From cheater00social at gmail.com  Mon Dec  1 04:12:50 2025
From: cheater00social at gmail.com (cheater cheater)
Date: Mon, 1 Dec 2025 04:12:50 +0100
Subject: [sdiy] DC-1 MHz, through-zero FM, controlled,
 oscillator without core capacitor
Message-ID: <CAGn5V--RBknCC8YUbD_H-eOn2JgTv6b=PAqm8B5jbSDfg98ugg@mail.gmail.com>

I've been watching this video by Mr. Carlson:

https://www.youtube.com/watch?v=9r6ntkwAadY

It shows an old school diffuse red LED being used in reverse polarity
as a varactor diode, and a setup using a potentiometer and that LED is
used together in the same way as a multi-plate, variable, air
capacitor such as a tuning capacitor taken out of a vintage AM radio.

The range of the simple circuit in the video is about 2 MHz. It occurs
to me that one should be able to use a setup with two such oscillator
cores, where one is being controlled, and the other one is at the
middle of its range, together with some static low pass filters to
extract only the fundamental sine waves, and a ring modulator, in
order to get A-B mixing products to extract the full range and to
center the range around 0 Hz and not around 27 MHz. Shaping to square
wave, triangle, and other synthesizer waveforms is possible starting
with a sine wave.

The low pass filters could probably require some form of capacitance,
but maybe inductors are better suited. I think there might exist
inexpensive premade brickwall filter modules for this sort of
frequency range, but I'm not a radio guy.

The circuit is demonstrated to be voltage controllable using light, by
using another LED, which can be fed constant current, dependent on
voltage input. This setup makes the control circuit electrically
decoupled from the oscillator and trivial to implement, essentially
building a vactrol.

The stability will probably suck, but if you want stability go play on a VST.

The 2 MHz range provides the capability to divide the frequency by 128
to achieve at least short-term stability, while numeric control could
provide correction current for long term drift. This could be achieved
by having a second copy of the oscillator running at a fixed
frequency, thermally coupled to the oscillator under control. The
second oscillator is input into a counter and control is exercised
using a PID loop in feedback. The oscillator core is low component
count and tiny in real estate, therefore it's easy to throw cores at a
problem until it's solved.

I hope someone plays around with this idea since I don't have a good
way of doing that myself at the moment.

I wonder if this would have a different sound than most typical VCOs,
especially if exposed to FM. If you make one, please post line-in
demos.

Cheers

From cheater00social at gmail.com  Mon Dec  1 04:31:35 2025
From: cheater00social at gmail.com (cheater cheater)
Date: Mon, 1 Dec 2025 04:31:35 +0100
Subject: [sdiy] DC-1 MHz, through-zero FM, controlled,
 oscillator without core capacitor
In-Reply-To: <CAGn5V--RBknCC8YUbD_H-eOn2JgTv6b=PAqm8B5jbSDfg98ugg@mail.gmail.com>
References: <CAGn5V--RBknCC8YUbD_H-eOn2JgTv6b=PAqm8B5jbSDfg98ugg@mail.gmail.com>
Message-ID: <CAGn5V-9_Vv8kxyEyj17g3fw42Br7ox1PX-UG6DgA363oUecqGQ@mail.gmail.com>

It makes sense to mention that the LED would be sealed off from light
except for the control light source, like in any other vactrol

On Mon, Dec 1, 2025 at 4:12?AM cheater cheater
<cheater00social at gmail.com> wrote:
>
> I've been watching this video by Mr. Carlson:
>
> https://www.youtube.com/watch?v=9r6ntkwAadY
>
> It shows an old school diffuse red LED being used in reverse polarity
> as a varactor diode, and a setup using a potentiometer and that LED is
> used together in the same way as a multi-plate, variable, air
> capacitor such as a tuning capacitor taken out of a vintage AM radio.
>
> The range of the simple circuit in the video is about 2 MHz. It occurs
> to me that one should be able to use a setup with two such oscillator
> cores, where one is being controlled, and the other one is at the
> middle of its range, together with some static low pass filters to
> extract only the fundamental sine waves, and a ring modulator, in
> order to get A-B mixing products to extract the full range and to
> center the range around 0 Hz and not around 27 MHz. Shaping to square
> wave, triangle, and other synthesizer waveforms is possible starting
> with a sine wave.
>
> The low pass filters could probably require some form of capacitance,
> but maybe inductors are better suited. I think there might exist
> inexpensive premade brickwall filter modules for this sort of
> frequency range, but I'm not a radio guy.
>
> The circuit is demonstrated to be voltage controllable using light, by
> using another LED, which can be fed constant current, dependent on
> voltage input. This setup makes the control circuit electrically
> decoupled from the oscillator and trivial to implement, essentially
> building a vactrol.
>
> The stability will probably suck, but if you want stability go play on a VST.
>
> The 2 MHz range provides the capability to divide the frequency by 128
> to achieve at least short-term stability, while numeric control could
> provide correction current for long term drift. This could be achieved
> by having a second copy of the oscillator running at a fixed
> frequency, thermally coupled to the oscillator under control. The
> second oscillator is input into a counter and control is exercised
> using a PID loop in feedback. The oscillator core is low component
> count and tiny in real estate, therefore it's easy to throw cores at a
> problem until it's solved.
>
> I hope someone plays around with this idea since I don't have a good
> way of doing that myself at the moment.
>
> I wonder if this would have a different sound than most typical VCOs,
> especially if exposed to FM. If you make one, please post line-in
> demos.
>
> Cheers


From rburnett at richieburnett.co.uk  Mon Dec  1 09:59:43 2025
From: rburnett at richieburnett.co.uk (rburnett at richieburnett.co.uk)
Date: Mon, 01 Dec 2025 08:59:43 +0000
Subject: [sdiy] DC-1 MHz, through-zero FM, controlled,
 oscillator without core capacitor
In-Reply-To: <CAGn5V-9_Vv8kxyEyj17g3fw42Br7ox1PX-UG6DgA363oUecqGQ@mail.gmail.com>
References: <CAGn5V--RBknCC8YUbD_H-eOn2JgTv6b=PAqm8B5jbSDfg98ugg@mail.gmail.com>
 <CAGn5V-9_Vv8kxyEyj17g3fw42Br7ox1PX-UG6DgA363oUecqGQ@mail.gmail.com>
Message-ID: <6ca6dc99ef73483de566c6f1a96255c9@richieburnett.co.uk>

It will work.  Varactor (varicap) diode VCOs are nothing new, although 
they usually use a diode designed specifically for the job instead of an 
LED! Likewise the hetrodyning (RF product "mixing") is a well 
established technique in radio transmitters/receivers for shifting 
frequencies up or down.

The downsides of varicap VCOs are drift and poor linearity (MHz/volt) of 
the control law. Both of these issues are typically solved in a modern 
radio transmitter or receiver by making the VCO be part of a PLL 
structure. This locks the VCO frequency to any one of a number of 
multiples of an accurate (crystal) reference frequency. Then you get the 
best of both worlds: adjustable frequency with perfect control 
linearity, combined with crystal accuracy and low drift.

If you mix together two RF signals up in the MHz to produce an audio 
tone the resulting pitch will be *incredibly* sensitive to tiny 
percentage changes in either of the RF oscillator's frequencies, and 
things like phase noise. Whether the result sounds to your liking is 
another matter!  I'd expect it to sound like a Theremin because that's 
essentially the mechanism that it uses to generate audio.

-Richie,


On 2025-12-01 03:31, cheater cheater via Synth-diy wrote:
> It makes sense to mention that the LED would be sealed off from light
> except for the control light source, like in any other vactrol
> 
> On Mon, Dec 1, 2025 at 4:12?AM cheater cheater
> <cheater00social at gmail.com> wrote:
>> 
>> I've been watching this video by Mr. Carlson:
>> 
>> https://www.youtube.com/watch?v=9r6ntkwAadY
>> 
>> It shows an old school diffuse red LED being used in reverse polarity
>> as a varactor diode, and a setup using a potentiometer and that LED is
>> used together in the same way as a multi-plate, variable, air
>> capacitor such as a tuning capacitor taken out of a vintage AM radio.
>> 
>> The range of the simple circuit in the video is about 2 MHz. It occurs
>> to me that one should be able to use a setup with two such oscillator
>> cores, where one is being controlled, and the other one is at the
>> middle of its range, together with some static low pass filters to
>> extract only the fundamental sine waves, and a ring modulator, in
>> order to get A-B mixing products to extract the full range and to
>> center the range around 0 Hz and not around 27 MHz. Shaping to square
>> wave, triangle, and other synthesizer waveforms is possible starting
>> with a sine wave.
>> 
>> The low pass filters could probably require some form of capacitance,
>> but maybe inductors are better suited. I think there might exist
>> inexpensive premade brickwall filter modules for this sort of
>> frequency range, but I'm not a radio guy.
>> 
>> The circuit is demonstrated to be voltage controllable using light, by
>> using another LED, which can be fed constant current, dependent on
>> voltage input. This setup makes the control circuit electrically
>> decoupled from the oscillator and trivial to implement, essentially
>> building a vactrol.
>> 
>> The stability will probably suck, but if you want stability go play on 
>> a VST.
>> 
>> The 2 MHz range provides the capability to divide the frequency by 128
>> to achieve at least short-term stability, while numeric control could
>> provide correction current for long term drift. This could be achieved
>> by having a second copy of the oscillator running at a fixed
>> frequency, thermally coupled to the oscillator under control. The
>> second oscillator is input into a counter and control is exercised
>> using a PID loop in feedback. The oscillator core is low component
>> count and tiny in real estate, therefore it's easy to throw cores at a
>> problem until it's solved.
>> 
>> I hope someone plays around with this idea since I don't have a good
>> way of doing that myself at the moment.
>> 
>> I wonder if this would have a different sound than most typical VCOs,
>> especially if exposed to FM. If you make one, please post line-in
>> demos.
>> 
>> Cheers
> 
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: 
> https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org

From modular at go2.pl  Mon Dec  1 13:47:38 2025
From: modular at go2.pl (Roman Sowa)
Date: Mon, 1 Dec 2025 13:47:38 +0100
Subject: [sdiy] Fet to short pedal input?
In-Reply-To: <408DCAF0-2AB0-47DD-8408-7A9F1D145E03@audiobanshee.com>
References: <LV8P222MB086185165F919557556BA913C4DFA@LV8P222MB0861.NAMP222.PROD.OUTLOOK.COM>
 <88669F3D-8FE2-480A-8E3F-B2E0231198D9@electricdruid.net>
 <SJ2P222MB08544A45AA7603B5E5BFD9FCC4DFA@SJ2P222MB0854.NAMP222.PROD.OUTLOOK.COM>
 <60DD7913-D1BD-4751-A885-C4BCEA46984A@audiobanshee.com>
 <81ed2801-72c6-4568-b27f-405236f05d7a@go2.pl>
 <408DCAF0-2AB0-47DD-8408-7A9F1D145E03@audiobanshee.com>
Message-ID: <0dad7a71-bb12-4609-bc45-7bebf7871ff9@go2.pl>



W dniu 2025-11-28 o?22:09, brianw pisze:
> 
> I am aware that saturation mode exists, but I don't really understand how to design with that mode. At the very least, I never see it in circuits outside power supply regulation or power amplification. In particular, I've never seen a saturated BJT used like an electronic bypass switch, which seems like what is needed here.

Maybe it sound strange not to use MOSFET but BJT as bypass switch, 
nevertheless it can be used. Maybe my response was too emotional, and 
this is widespread the reality. Once I was asked for help by well known 
eurorack maker in simple transistor circuit and it turned out that they 
don't have a lightest idea how BJTs work. I guess even PhD in signal 
processing soesn't help with basics.

> 
> I've only ever seen FET used for muting. In particular, I've seen depletion mode N-FET used because they conduct (to ground, in a mute circuit) when no voltage is applied to the gate. How would a BJT remain in saturation mode when all power is lost to the device?


I've seen many time BJTs used for muting, especially in synth outputs. 
They are activated straight from the power supply, just behind 
rectifier, before voltages rise to start any other activity. Then it's 
unmuted by control unit when boot up is done.

Roman

From modular at go2.pl  Mon Dec  1 13:53:30 2025
From: modular at go2.pl (Roman Sowa)
Date: Mon, 1 Dec 2025 13:53:30 +0100
Subject: [sdiy] Fet to short pedal input?
In-Reply-To: <CACodTR_LZV-=Jhdc1W6gegP56__Ffh9i+O8RvUoFt9pU8-OKTw@mail.gmail.com>
References: <LV8P222MB086185165F919557556BA913C4DFA@LV8P222MB0861.NAMP222.PROD.OUTLOOK.COM>
 <6EB328FA-4CED-4FEA-B71D-5FC225F3AA9B@electricdruid.net>
 <b9071728-2ee6-4aaa-afed-8e222dd6ec71@proton.me>
 <CAAv6=UDGL6s0saNdiVPqS=eVQ_FBNJxO=zJ=2wpFS-9AaHuH2g@mail.gmail.com>
 <76EDE146-E986-488E-89D3-53EFCE5694EC@audiobanshee.com>
 <CACodTR_LZV-=Jhdc1W6gegP56__Ffh9i+O8RvUoFt9pU8-OKTw@mail.gmail.com>
Message-ID: <e9d665f6-a099-4a8e-b900-22fb92917c07@go2.pl>

Neither drain or source has to be "fixed". They can fly at whatever 
voltages both sides of glide pot is experiencing. You only need to make 
sure that gate voltage is a few voltages higher than any possible Source 
voltage to turn it on, and at least no higher than Source to turn it 
off. In simple terms, switch it between plus and minus power rails, r as 
in this case between +15 and 0V should be enough.
And to get rid of substrate diode that will spoil it in glide circuit, 
just connect 2 MOSFETs back to back. Or should I say source to source.
Common MOSFETs accept +/-20V Ugs

Roman

W dniu 2025-11-28 o?22:51, Pete Hartman via Synth-diy pisze:
> Am I just missing something here? If neither the Source nor the Drain is 
> tied to anything resembling a fixed voltage, then what does the Gate 
> have to "compare" to (yes I'm being imprecise about the mechanism of a FET).
> 
> When one side is a ground, certainly, that makes sense to use a FET for 
> muting or even a BJT for switching (I've done the same).? But FETs 
> floating in the air ... unless there's a DC offset in that signal going 
> to the portamento circuit that can be relied on, I don't see how that 
> would work.
> 
> On Fri, Nov 28, 2025 at 3:26?PM brianw <brianw at audiobanshee.com 
> <mailto:brianw at audiobanshee.com>> wrote:
> 
>     A relay will certainly have the conductive properties of the pedal
>     switch.
> 
>     My questions are 1) how fast will the relay open circuit after the
>     Frostwave converts MIDI velocity to voltage? and 2) how many notes
>     can you play before the relay wears out?
> 
>     If the relay doesn't 'release' quickly enough, then the portamento
>     won't work as expected, since the early part of the note will jump
>     instantly towards the new pitch CV. In other words, the timing
>     between the Note On gate (when the pitch CV changes) and the relay
>     disengaging has to be zero (or less!). One possible solution is to
>     delay the Gate - perhaps using the Frostwave as the gate source.
> 
>     Brian
> 
> 
>     On Nov 28, 2025, at 7:39 AM, Michael E Caloroso wrote:
>      > You really need a control element with infinite resistance (open
>     circuit).? That element needs to have open circuit and short circuit
>     states and it's hard to beat a relay controlled by a Darlington BJT.
> 
> 
>     ________________________________________________________
>     This is the Synth-diy mailing list
>     Submit email to: Synth-diy at synth-diy.org
>     <mailto:Synth-diy at synth-diy.org>
>     View archive at: https://synth-diy.org/pipermail/synth-diy/
>     <https://synth-diy.org/pipermail/synth-diy/>
>     Check your settings at:
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>     <https://synth-diy.org/mailman/listinfo/synth-diy>
>     Selling or trading? Use marketplace at synth-diy.org
>     <mailto:marketplace at synth-diy.org>
> 
> 
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org

From tensiontype at hotmail.com  Mon Dec  1 14:00:22 2025
From: tensiontype at hotmail.com (Sean Ellis)
Date: Mon, 1 Dec 2025 13:00:22 +0000
Subject: [sdiy] Fet to short pedal input?
In-Reply-To: <CAP92RBWNKx0JbeMHg7E5K7sJrZq4hTJP83TqrfC5BEh2gg+jOQ@mail.gmail.com>
References: <LV8P222MB086185165F919557556BA913C4DFA@LV8P222MB0861.NAMP222.PROD.OUTLOOK.COM>
 <88669F3D-8FE2-480A-8E3F-B2E0231198D9@electricdruid.net>
 <SJ2P222MB08544A45AA7603B5E5BFD9FCC4DFA@SJ2P222MB0854.NAMP222.PROD.OUTLOOK.COM>
 <60DD7913-D1BD-4751-A885-C4BCEA46984A@audiobanshee.com>
 <81ed2801-72c6-4568-b27f-405236f05d7a@go2.pl>
 <408DCAF0-2AB0-47DD-8408-7A9F1D145E03@audiobanshee.com>
 <CAP92RBWNKx0JbeMHg7E5K7sJrZq4hTJP83TqrfC5BEh2gg+jOQ@mail.gmail.com>
Message-ID: <KL1PR02MB6663235DFF5F9FD4C4AB8834B3DBA@KL1PR02MB6663.apcprd02.prod.outlook.com>


The current Korg synths still use BJTs for this as seen in the Prologue 8 service manual (which I just discovered!)


Https://www.manualslib.com/manual/2518830/Korg-Prologue-8.html?page=37<https://www.manualslib.com/manual/2518830/Korg-Prologue-8.html?page=37>

________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Mattias Rickardsson <mr at analogue.org>
Sent: Friday, 28 November 2025 10:20 PM
To: brianw <brianw at audiobanshee.com>
Cc: synth-diy at synth-diy.org <synth-diy at synth-diy.org>
Subject: Re: [sdiy] Fet to short pedal input?

On Fri, 28 Nov 2025 at 22:12, brianw <brianw at audiobanshee.com<mailto:brianw at audiobanshee.com>> wrote:
On Nov 28, 2025, at 2:09 AM, Roman Sowa <modular at go2.pl<mailto:modular at go2.pl>> wrote:

> BTW, BJTs are most commonly used everywhere for muting output jacks during powerup or whatever other reasons, because it works so much better than FET in this application

I've only ever seen FET used for muting. In particular, I've seen depletion mode N-FET used because they conduct (to ground, in a mute circuit) when no voltage is applied to the gate. How would a BJT remain in saturation mode when all power is lost to the device?

I'd call this usecase "muting" (with big wavy rabbit ears around it) where the output clicks just need to become less loud, not necessarily silent. Here I've seen and used BJTs.
For real muting, where the signal needs to be muted for real, I've seen and used FETs and CMOS switches/muxes. :-)

/mr
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From cheater00social at gmail.com  Mon Dec  1 17:21:30 2025
From: cheater00social at gmail.com (cheater cheater)
Date: Mon, 1 Dec 2025 17:21:30 +0100
Subject: [sdiy] DC-1 MHz, through-zero FM, controlled,
 oscillator without core capacitor
In-Reply-To: <6ca6dc99ef73483de566c6f1a96255c9@richieburnett.co.uk>
References: <CAGn5V--RBknCC8YUbD_H-eOn2JgTv6b=PAqm8B5jbSDfg98ugg@mail.gmail.com>
 <CAGn5V-9_Vv8kxyEyj17g3fw42Br7ox1PX-UG6DgA363oUecqGQ@mail.gmail.com>
 <6ca6dc99ef73483de566c6f1a96255c9@richieburnett.co.uk>
Message-ID: <CAGn5V--t1MWtWD5GC3cSCDHJZbxY+kBi4R2p4rZrQQJ6mhT=MA@mail.gmail.com>

Interesting! I had no idea that was how a Theremin worked. Those can
keep the pitch really well, actually.

A PLL would mean completely digital control, wouldn't it?

Do PLLs like that respond well to audio rate modulation?

The idea with a second core was to let the oscillator drift a little
bit owing to its analog nature, while also correcting for the gross
drift. Do you think that would keep things close enough in tune to be
musically useful?

Low bass on a Theremin sounds pretty good.
https://www.youtube.com/watch?v=CgPgasgoVbU

I think a large portion of the sound is a question of wave shaping.

On Mon, Dec 1, 2025 at 9:59?AM <rburnett at richieburnett.co.uk> wrote:
>
> It will work.  Varactor (varicap) diode VCOs are nothing new, although
> they usually use a diode designed specifically for the job instead of an
> LED! Likewise the hetrodyning (RF product "mixing") is a well
> established technique in radio transmitters/receivers for shifting
> frequencies up or down.
>
> The downsides of varicap VCOs are drift and poor linearity (MHz/volt) of
> the control law. Both of these issues are typically solved in a modern
> radio transmitter or receiver by making the VCO be part of a PLL
> structure. This locks the VCO frequency to any one of a number of
> multiples of an accurate (crystal) reference frequency. Then you get the
> best of both worlds: adjustable frequency with perfect control
> linearity, combined with crystal accuracy and low drift.
>
> If you mix together two RF signals up in the MHz to produce an audio
> tone the resulting pitch will be *incredibly* sensitive to tiny
> percentage changes in either of the RF oscillator's frequencies, and
> things like phase noise. Whether the result sounds to your liking is
> another matter!  I'd expect it to sound like a Theremin because that's
> essentially the mechanism that it uses to generate audio.
>
> -Richie,
>
>
> On 2025-12-01 03:31, cheater cheater via Synth-diy wrote:
> > It makes sense to mention that the LED would be sealed off from light
> > except for the control light source, like in any other vactrol
> >
> > On Mon, Dec 1, 2025 at 4:12?AM cheater cheater
> > <cheater00social at gmail.com> wrote:
> >>
> >> I've been watching this video by Mr. Carlson:
> >>
> >> https://www.youtube.com/watch?v=9r6ntkwAadY
> >>
> >> It shows an old school diffuse red LED being used in reverse polarity
> >> as a varactor diode, and a setup using a potentiometer and that LED is
> >> used together in the same way as a multi-plate, variable, air
> >> capacitor such as a tuning capacitor taken out of a vintage AM radio.
> >>
> >> The range of the simple circuit in the video is about 2 MHz. It occurs
> >> to me that one should be able to use a setup with two such oscillator
> >> cores, where one is being controlled, and the other one is at the
> >> middle of its range, together with some static low pass filters to
> >> extract only the fundamental sine waves, and a ring modulator, in
> >> order to get A-B mixing products to extract the full range and to
> >> center the range around 0 Hz and not around 27 MHz. Shaping to square
> >> wave, triangle, and other synthesizer waveforms is possible starting
> >> with a sine wave.
> >>
> >> The low pass filters could probably require some form of capacitance,
> >> but maybe inductors are better suited. I think there might exist
> >> inexpensive premade brickwall filter modules for this sort of
> >> frequency range, but I'm not a radio guy.
> >>
> >> The circuit is demonstrated to be voltage controllable using light, by
> >> using another LED, which can be fed constant current, dependent on
> >> voltage input. This setup makes the control circuit electrically
> >> decoupled from the oscillator and trivial to implement, essentially
> >> building a vactrol.
> >>
> >> The stability will probably suck, but if you want stability go play on
> >> a VST.
> >>
> >> The 2 MHz range provides the capability to divide the frequency by 128
> >> to achieve at least short-term stability, while numeric control could
> >> provide correction current for long term drift. This could be achieved
> >> by having a second copy of the oscillator running at a fixed
> >> frequency, thermally coupled to the oscillator under control. The
> >> second oscillator is input into a counter and control is exercised
> >> using a PID loop in feedback. The oscillator core is low component
> >> count and tiny in real estate, therefore it's easy to throw cores at a
> >> problem until it's solved.
> >>
> >> I hope someone plays around with this idea since I don't have a good
> >> way of doing that myself at the moment.
> >>
> >> I wonder if this would have a different sound than most typical VCOs,
> >> especially if exposed to FM. If you make one, please post line-in
> >> demos.
> >>
> >> Cheers
> >
> > ________________________________________________________
> > This is the Synth-diy mailing list
> > Submit email to: Synth-diy at synth-diy.org
> > View archive at: https://synth-diy.org/pipermail/synth-diy/
> > Check your settings at:
> > https://synth-diy.org/mailman/listinfo/synth-diy
> > Selling or trading? Use marketplace at synth-diy.org


From chromatest at chromatest.net  Mon Dec  1 22:11:36 2025
From: chromatest at chromatest.net (Chromatest J. Pantsmaker)
Date: Mon, 1 Dec 2025 14:11:36 -0700
Subject: [sdiy] DC-1 MHz, through-zero FM, controlled,
 oscillator without core capacitor
In-Reply-To: <CAGn5V--t1MWtWD5GC3cSCDHJZbxY+kBi4R2p4rZrQQJ6mhT=MA@mail.gmail.com>
References: <CAGn5V--RBknCC8YUbD_H-eOn2JgTv6b=PAqm8B5jbSDfg98ugg@mail.gmail.com>
 <CAGn5V-9_Vv8kxyEyj17g3fw42Br7ox1PX-UG6DgA363oUecqGQ@mail.gmail.com>
 <6ca6dc99ef73483de566c6f1a96255c9@richieburnett.co.uk>
 <CAGn5V--t1MWtWD5GC3cSCDHJZbxY+kBi4R2p4rZrQQJ6mhT=MA@mail.gmail.com>
Message-ID: <CADpm=3HL1anPtPeyKOALHzT5-qsY-FBP4egBE_EJYOBK2qg1tg@mail.gmail.com>

I think you would implement the PLL circuitry *before* the audio-rate
modulation.

On Mon, Dec 1, 2025, 9:22?AM cheater cheater via Synth-diy <
synth-diy at synth-diy.org> wrote:

> Interesting! I had no idea that was how a Theremin worked. Those can
> keep the pitch really well, actually.
>
> A PLL would mean completely digital control, wouldn't it?
>
> Do PLLs like that respond well to audio rate modulation?
>
> The idea with a second core was to let the oscillator drift a little
> bit owing to its analog nature, while also correcting for the gross
> drift. Do you think that would keep things close enough in tune to be
> musically useful?
>
> Low bass on a Theremin sounds pretty good.
> https://www.youtube.com/watch?v=CgPgasgoVbU
>
> I think a large portion of the sound is a question of wave shaping.
>
> On Mon, Dec 1, 2025 at 9:59?AM <rburnett at richieburnett.co.uk> wrote:
> >
> > It will work.  Varactor (varicap) diode VCOs are nothing new, although
> > they usually use a diode designed specifically for the job instead of an
> > LED! Likewise the hetrodyning (RF product "mixing") is a well
> > established technique in radio transmitters/receivers for shifting
> > frequencies up or down.
> >
> > The downsides of varicap VCOs are drift and poor linearity (MHz/volt) of
> > the control law. Both of these issues are typically solved in a modern
> > radio transmitter or receiver by making the VCO be part of a PLL
> > structure. This locks the VCO frequency to any one of a number of
> > multiples of an accurate (crystal) reference frequency. Then you get the
> > best of both worlds: adjustable frequency with perfect control
> > linearity, combined with crystal accuracy and low drift.
> >
> > If you mix together two RF signals up in the MHz to produce an audio
> > tone the resulting pitch will be *incredibly* sensitive to tiny
> > percentage changes in either of the RF oscillator's frequencies, and
> > things like phase noise. Whether the result sounds to your liking is
> > another matter!  I'd expect it to sound like a Theremin because that's
> > essentially the mechanism that it uses to generate audio.
> >
> > -Richie,
> >
> >
> > On 2025-12-01 03:31, cheater cheater via Synth-diy wrote:
> > > It makes sense to mention that the LED would be sealed off from light
> > > except for the control light source, like in any other vactrol
> > >
> > > On Mon, Dec 1, 2025 at 4:12?AM cheater cheater
> > > <cheater00social at gmail.com> wrote:
> > >>
> > >> I've been watching this video by Mr. Carlson:
> > >>
> > >> https://www.youtube.com/watch?v=9r6ntkwAadY
> > >>
> > >> It shows an old school diffuse red LED being used in reverse polarity
> > >> as a varactor diode, and a setup using a potentiometer and that LED is
> > >> used together in the same way as a multi-plate, variable, air
> > >> capacitor such as a tuning capacitor taken out of a vintage AM radio.
> > >>
> > >> The range of the simple circuit in the video is about 2 MHz. It occurs
> > >> to me that one should be able to use a setup with two such oscillator
> > >> cores, where one is being controlled, and the other one is at the
> > >> middle of its range, together with some static low pass filters to
> > >> extract only the fundamental sine waves, and a ring modulator, in
> > >> order to get A-B mixing products to extract the full range and to
> > >> center the range around 0 Hz and not around 27 MHz. Shaping to square
> > >> wave, triangle, and other synthesizer waveforms is possible starting
> > >> with a sine wave.
> > >>
> > >> The low pass filters could probably require some form of capacitance,
> > >> but maybe inductors are better suited. I think there might exist
> > >> inexpensive premade brickwall filter modules for this sort of
> > >> frequency range, but I'm not a radio guy.
> > >>
> > >> The circuit is demonstrated to be voltage controllable using light, by
> > >> using another LED, which can be fed constant current, dependent on
> > >> voltage input. This setup makes the control circuit electrically
> > >> decoupled from the oscillator and trivial to implement, essentially
> > >> building a vactrol.
> > >>
> > >> The stability will probably suck, but if you want stability go play on
> > >> a VST.
> > >>
> > >> The 2 MHz range provides the capability to divide the frequency by 128
> > >> to achieve at least short-term stability, while numeric control could
> > >> provide correction current for long term drift. This could be achieved
> > >> by having a second copy of the oscillator running at a fixed
> > >> frequency, thermally coupled to the oscillator under control. The
> > >> second oscillator is input into a counter and control is exercised
> > >> using a PID loop in feedback. The oscillator core is low component
> > >> count and tiny in real estate, therefore it's easy to throw cores at a
> > >> problem until it's solved.
> > >>
> > >> I hope someone plays around with this idea since I don't have a good
> > >> way of doing that myself at the moment.
> > >>
> > >> I wonder if this would have a different sound than most typical VCOs,
> > >> especially if exposed to FM. If you make one, please post line-in
> > >> demos.
> > >>
> > >> Cheers
> > >
> > > ________________________________________________________
> > > This is the Synth-diy mailing list
> > > Submit email to: Synth-diy at synth-diy.org
> > > View archive at: https://synth-diy.org/pipermail/synth-diy/
> > > Check your settings at:
> > > https://synth-diy.org/mailman/listinfo/synth-diy
> > > Selling or trading? Use marketplace at synth-diy.org
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
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From cheater00social at gmail.com  Mon Dec  1 22:30:03 2025
From: cheater00social at gmail.com (cheater cheater)
Date: Mon, 1 Dec 2025 22:30:03 +0100
Subject: [sdiy] DC-1 MHz, through-zero FM, controlled,
 oscillator without core capacitor
In-Reply-To: <CADpm=3HL1anPtPeyKOALHzT5-qsY-FBP4egBE_EJYOBK2qg1tg@mail.gmail.com>
References: <CAGn5V--RBknCC8YUbD_H-eOn2JgTv6b=PAqm8B5jbSDfg98ugg@mail.gmail.com>
 <CAGn5V-9_Vv8kxyEyj17g3fw42Br7ox1PX-UG6DgA363oUecqGQ@mail.gmail.com>
 <6ca6dc99ef73483de566c6f1a96255c9@richieburnett.co.uk>
 <CAGn5V--t1MWtWD5GC3cSCDHJZbxY+kBi4R2p4rZrQQJ6mhT=MA@mail.gmail.com>
 <CADpm=3HL1anPtPeyKOALHzT5-qsY-FBP4egBE_EJYOBK2qg1tg@mail.gmail.com>
Message-ID: <CAGn5V--_kkp0vaM2TQH=6yHopWakprB5qcw-hamn0yPnJ_xz_g@mail.gmail.com>

frequency modulation inputs can carry both DC and AC components in one signal.

On Mon, Dec 1, 2025 at 10:11?PM Chromatest J. Pantsmaker
<chromatest at chromatest.net> wrote:
>
> I think you would implement the PLL circuitry *before* the audio-rate modulation.
>
> On Mon, Dec 1, 2025, 9:22?AM cheater cheater via Synth-diy <synth-diy at synth-diy.org> wrote:
>>
>> Interesting! I had no idea that was how a Theremin worked. Those can
>> keep the pitch really well, actually.
>>
>> A PLL would mean completely digital control, wouldn't it?
>>
>> Do PLLs like that respond well to audio rate modulation?
>>
>> The idea with a second core was to let the oscillator drift a little
>> bit owing to its analog nature, while also correcting for the gross
>> drift. Do you think that would keep things close enough in tune to be
>> musically useful?
>>
>> Low bass on a Theremin sounds pretty good.
>> https://www.youtube.com/watch?v=CgPgasgoVbU
>>
>> I think a large portion of the sound is a question of wave shaping.
>>
>> On Mon, Dec 1, 2025 at 9:59?AM <rburnett at richieburnett.co.uk> wrote:
>> >
>> > It will work.  Varactor (varicap) diode VCOs are nothing new, although
>> > they usually use a diode designed specifically for the job instead of an
>> > LED! Likewise the hetrodyning (RF product "mixing") is a well
>> > established technique in radio transmitters/receivers for shifting
>> > frequencies up or down.
>> >
>> > The downsides of varicap VCOs are drift and poor linearity (MHz/volt) of
>> > the control law. Both of these issues are typically solved in a modern
>> > radio transmitter or receiver by making the VCO be part of a PLL
>> > structure. This locks the VCO frequency to any one of a number of
>> > multiples of an accurate (crystal) reference frequency. Then you get the
>> > best of both worlds: adjustable frequency with perfect control
>> > linearity, combined with crystal accuracy and low drift.
>> >
>> > If you mix together two RF signals up in the MHz to produce an audio
>> > tone the resulting pitch will be *incredibly* sensitive to tiny
>> > percentage changes in either of the RF oscillator's frequencies, and
>> > things like phase noise. Whether the result sounds to your liking is
>> > another matter!  I'd expect it to sound like a Theremin because that's
>> > essentially the mechanism that it uses to generate audio.
>> >
>> > -Richie,
>> >
>> >
>> > On 2025-12-01 03:31, cheater cheater via Synth-diy wrote:
>> > > It makes sense to mention that the LED would be sealed off from light
>> > > except for the control light source, like in any other vactrol
>> > >
>> > > On Mon, Dec 1, 2025 at 4:12?AM cheater cheater
>> > > <cheater00social at gmail.com> wrote:
>> > >>
>> > >> I've been watching this video by Mr. Carlson:
>> > >>
>> > >> https://www.youtube.com/watch?v=9r6ntkwAadY
>> > >>
>> > >> It shows an old school diffuse red LED being used in reverse polarity
>> > >> as a varactor diode, and a setup using a potentiometer and that LED is
>> > >> used together in the same way as a multi-plate, variable, air
>> > >> capacitor such as a tuning capacitor taken out of a vintage AM radio.
>> > >>
>> > >> The range of the simple circuit in the video is about 2 MHz. It occurs
>> > >> to me that one should be able to use a setup with two such oscillator
>> > >> cores, where one is being controlled, and the other one is at the
>> > >> middle of its range, together with some static low pass filters to
>> > >> extract only the fundamental sine waves, and a ring modulator, in
>> > >> order to get A-B mixing products to extract the full range and to
>> > >> center the range around 0 Hz and not around 27 MHz. Shaping to square
>> > >> wave, triangle, and other synthesizer waveforms is possible starting
>> > >> with a sine wave.
>> > >>
>> > >> The low pass filters could probably require some form of capacitance,
>> > >> but maybe inductors are better suited. I think there might exist
>> > >> inexpensive premade brickwall filter modules for this sort of
>> > >> frequency range, but I'm not a radio guy.
>> > >>
>> > >> The circuit is demonstrated to be voltage controllable using light, by
>> > >> using another LED, which can be fed constant current, dependent on
>> > >> voltage input. This setup makes the control circuit electrically
>> > >> decoupled from the oscillator and trivial to implement, essentially
>> > >> building a vactrol.
>> > >>
>> > >> The stability will probably suck, but if you want stability go play on
>> > >> a VST.
>> > >>
>> > >> The 2 MHz range provides the capability to divide the frequency by 128
>> > >> to achieve at least short-term stability, while numeric control could
>> > >> provide correction current for long term drift. This could be achieved
>> > >> by having a second copy of the oscillator running at a fixed
>> > >> frequency, thermally coupled to the oscillator under control. The
>> > >> second oscillator is input into a counter and control is exercised
>> > >> using a PID loop in feedback. The oscillator core is low component
>> > >> count and tiny in real estate, therefore it's easy to throw cores at a
>> > >> problem until it's solved.
>> > >>
>> > >> I hope someone plays around with this idea since I don't have a good
>> > >> way of doing that myself at the moment.
>> > >>
>> > >> I wonder if this would have a different sound than most typical VCOs,
>> > >> especially if exposed to FM. If you make one, please post line-in
>> > >> demos.
>> > >>
>> > >> Cheers
>> > >
>> > > ________________________________________________________
>> > > This is the Synth-diy mailing list
>> > > Submit email to: Synth-diy at synth-diy.org
>> > > View archive at: https://synth-diy.org/pipermail/synth-diy/
>> > > Check your settings at:
>> > > https://synth-diy.org/mailman/listinfo/synth-diy
>> > > Selling or trading? Use marketplace at synth-diy.org
>>
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org
>> View archive at: https://synth-diy.org/pipermail/synth-diy/
>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org


From ben at stuyts.nl  Mon Dec  1 22:58:18 2025
From: ben at stuyts.nl (Ben Stuyts)
Date: Mon, 1 Dec 2025 22:58:18 +0100
Subject: [sdiy] DC-1 MHz, through-zero FM, controlled,
 oscillator without core capacitor
In-Reply-To: <6ca6dc99ef73483de566c6f1a96255c9@richieburnett.co.uk>
References: <CAGn5V--RBknCC8YUbD_H-eOn2JgTv6b=PAqm8B5jbSDfg98ugg@mail.gmail.com>
 <CAGn5V-9_Vv8kxyEyj17g3fw42Br7ox1PX-UG6DgA363oUecqGQ@mail.gmail.com>
 <6ca6dc99ef73483de566c6f1a96255c9@richieburnett.co.uk>
Message-ID: <9A9B14F8-EB2E-4B82-A829-1BE47BEE3CC1@stuyts.nl>


> On 1 Dec 2025, at 09:59, rburnett at richieburnett.co.uk wrote:
> 
> It will work.  Varactor (varicap) diode VCOs are nothing new, although they usually use a diode designed specifically for the job instead of an LED! Likewise the hetrodyning (RF product "mixing") is a well established technique in radio transmitters/receivers for shifting frequencies up or down.
> 
> The downsides of varicap VCOs are drift and poor linearity (MHz/volt) of the control law. Both of these issues are typically solved in a modern radio transmitter or receiver by making the VCO be part of a PLL structure. This locks the VCO frequency to any one of a number of multiples of an accurate (crystal) reference frequency. Then you get the best of both worlds: adjustable frequency with perfect control linearity, combined with crystal accuracy and low drift.
> 
> If you mix together two RF signals up in the MHz to produce an audio tone the resulting pitch will be *incredibly* sensitive to tiny percentage changes in either of the RF oscillator's frequencies, and things like phase noise. Whether the result sounds to your liking is another matter!  I'd expect it to sound like a Theremin because that's essentially the mechanism that it uses to generate audio.

Minor detail, in the Theremin, the hand-waving *is* the actual change in capacitance. The antenna is part of the tuned LC circuit in one of the oscillators. So no varicap diodes needed. Here is an early article from master theremin builder Bob Moog: https://ia600107.us.archive.org/23/items/synthmanual-moog-the-theremin-article/moogthethereminarticle_text.pdf

Ben

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From rburnett at richieburnett.co.uk  Mon Dec  1 23:50:11 2025
From: rburnett at richieburnett.co.uk (Richie Burnett)
Date: Mon, 1 Dec 2025 22:50:11 -0000
Subject: [sdiy] DC-1 MHz, through-zero FM, controlled,
 oscillator without core capacitor
In-Reply-To: <CAGn5V--t1MWtWD5GC3cSCDHJZbxY+kBi4R2p4rZrQQJ6mhT=MA@mail.gmail.com>
References: <CAGn5V--RBknCC8YUbD_H-eOn2JgTv6b=PAqm8B5jbSDfg98ugg@mail.gmail.com>
 <CAGn5V-9_Vv8kxyEyj17g3fw42Br7ox1PX-UG6DgA363oUecqGQ@mail.gmail.com>
 <6ca6dc99ef73483de566c6f1a96255c9@richieburnett.co.uk>
 <CAGn5V--t1MWtWD5GC3cSCDHJZbxY+kBi4R2p4rZrQQJ6mhT=MA@mail.gmail.com>
Message-ID: <C1B56265520E45D2994AD9F1CF124328@DESKTOPUHPK2VO>

> Interesting! I had no idea that was how a Theremin worked. Those can
keep the pitch really well, actually.

Perhaps if you are a player skilled in the art! ;-))

> A PLL would mean completely digital control, wouldn't it?

For the coarse pitch control in steps, yes.

> Do PLLs like that respond well to audio rate modulation?

There's two options...

1. You apply frequency modulation to the PLL's reference, and you make the 
PLL's response really fast so that its control loop acts to make the VCO 
track the instantaneous modulation on the reference.

_OR_

2. You mix the frequency modulation signal directly into the VCO's CV input 
and you make the PLL's response *really* slow, so that the feedback loop of 
the PLL doesn't try to remove the modulation by correcting for what it 
perceives as an unexpected error!

Both techniques have their own set of drawbacks though.  I've seen the 
second technique used in FM broadcast transmitters that claim digital PLL 
stability in the long-term for the carrier frequency, but still allow 
instantaneous analogue modulation of the frequency to impart the audio.  The 
downside is that the PLL usually takes *ages* to lock after a step change in 
frequency because the control loop has to be slow enough not to remove all 
of the bass from the audio!

> The idea with a second core was to let the oscillator drift a little
bit owing to its analog nature, while also correcting for the gross
drift. Do you think that would keep things close enough in tune to be
musically useful?

I don't know.

I'd be inclined to have one of the RF oscillators be a crystal oscillator. 
Then you only have the stability of one RF oscillator to worry about and/or 
compensate for in your system.

But then my preference would be for DDS rather than PLL anyway, because you 
get much more agile frequency control, in very fine steps (milli-hertz,) 
with none of the control-loop settling issues of a PLL, yet still keeping 
the crystal oscillator accuracy and long-term frequency stability.

-Richie, 


-- 
This email has been checked for viruses by AVG antivirus software.
www.avg.com

From grant at musictechnologiesgroup.com  Tue Dec  2 01:02:49 2025
From: grant at musictechnologiesgroup.com (grant musictechnologiesgroup.com)
Date: Tue, 2 Dec 2025 00:02:49 +0000
Subject: [sdiy] Fet to short pedal input?
In-Reply-To: <KL1PR02MB6663235DFF5F9FD4C4AB8834B3DBA@KL1PR02MB6663.apcprd02.prod.outlook.com>
References: <LV8P222MB086185165F919557556BA913C4DFA@LV8P222MB0861.NAMP222.PROD.OUTLOOK.COM>
 <88669F3D-8FE2-480A-8E3F-B2E0231198D9@electricdruid.net>
 <SJ2P222MB08544A45AA7603B5E5BFD9FCC4DFA@SJ2P222MB0854.NAMP222.PROD.OUTLOOK.COM>
 <60DD7913-D1BD-4751-A885-C4BCEA46984A@audiobanshee.com>
 <81ed2801-72c6-4568-b27f-405236f05d7a@go2.pl>
 <408DCAF0-2AB0-47DD-8408-7A9F1D145E03@audiobanshee.com>
 <CAP92RBWNKx0JbeMHg7E5K7sJrZq4hTJP83TqrfC5BEh2gg+jOQ@mail.gmail.com>
 <KL1PR02MB6663235DFF5F9FD4C4AB8834B3DBA@KL1PR02MB6663.apcprd02.prod.outlook.com>
Message-ID: <8ad5b1e0-6130-4700-b44f-e52c024d1e02@musictechnologiesgroup.com>

Geez, they have a whole truckload of STM32's in there. And I thought this was the Raspberry Pi musical instrument company...


On 12/1/2025 5:00 AM, Sean Ellis via Synth-diy wrote:

The current Korg synths still use BJTs for this as seen in the Prologue 8 service manual (which I just discovered!)


Https://www.manualslib.com/manual/2518830/Korg-Prologue-8.html?page=37<https://www.manualslib.com/manual/2518830/Korg-Prologue-8.html?page=37>

________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org><mailto:synth-diy-bounces at synth-diy.org> on behalf of Mattias Rickardsson <mr at analogue.org><mailto:mr at analogue.org>
Sent: Friday, 28 November 2025 10:20 PM
To: brianw <brianw at audiobanshee.com><mailto:brianw at audiobanshee.com>
Cc: synth-diy at synth-diy.org<mailto:synth-diy at synth-diy.org> <synth-diy at synth-diy.org><mailto:synth-diy at synth-diy.org>
Subject: Re: [sdiy] Fet to short pedal input?

On Fri, 28 Nov 2025 at 22:12, brianw <brianw at audiobanshee.com<mailto:brianw at audiobanshee.com>> wrote:
On Nov 28, 2025, at 2:09 AM, Roman Sowa <modular at go2.pl<mailto:modular at go2.pl>> wrote:

> BTW, BJTs are most commonly used everywhere for muting output jacks during powerup or whatever other reasons, because it works so much better than FET in this application

I've only ever seen FET used for muting. In particular, I've seen depletion mode N-FET used because they conduct (to ground, in a mute circuit) when no voltage is applied to the gate. How would a BJT remain in saturation mode when all power is lost to the device?

I'd call this usecase "muting" (with big wavy rabbit ears around it) where the output clicks just need to become less loud, not necessarily silent. Here I've seen and used BJTs.
For real muting, where the signal needs to be muted for real, I've seen and used FETs and CMOS switches/muxes. :-)

/mr



________________________________________________________
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Submit email to: Synth-diy at synth-diy.org<mailto:Synth-diy at synth-diy.org>
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From brianw at audiobanshee.com  Tue Dec  2 02:44:42 2025
From: brianw at audiobanshee.com (brianw)
Date: Mon, 1 Dec 2025 17:44:42 -0800
Subject: [sdiy] Fet to short pedal input?
In-Reply-To: <8ad5b1e0-6130-4700-b44f-e52c024d1e02@musictechnologiesgroup.com>
References: <LV8P222MB086185165F919557556BA913C4DFA@LV8P222MB0861.NAMP222.PROD.OUTLOOK.COM>
 <88669F3D-8FE2-480A-8E3F-B2E0231198D9@electricdruid.net>
 <SJ2P222MB08544A45AA7603B5E5BFD9FCC4DFA@SJ2P222MB0854.NAMP222.PROD.OUTLOOK.COM>
 <60DD7913-D1BD-4751-A885-C4BCEA46984A@audiobanshee.com>
 <81ed2801-72c6-4568-b27f-405236f05d7a@go2.pl>
 <408DCAF0-2AB0-47DD-8408-7A9F1D145E03@audiobanshee.com>
 <CAP92RBWNKx0JbeMHg7E5K7sJrZq4hTJP83TqrfC5BEh2gg+jOQ@mail.gmail.com>
 <KL1PR02MB6663235DFF5F9FD4C4AB8834B3DBA@KL1PR02MB6663.apcprd02.prod.outlook.com>
 <8ad5b1e0-6130-4700-b44f-e52c024d1e02@musictechnologiesgroup.com>
Message-ID: <B7AC2196-5363-41DD-B3B2-B716913C9E50@audiobanshee.com>

On Dec 1, 2025, at 4:02 PM, grant wrote:
> Geez, they have a whole truckload of STM32's in there. And I thought this was the Raspberry Pi musical instrument company...
> 
> On 12/1/2025 5:00 AM, Sean Ellis wrote:
>> 
>> https://www.manualslib.com/manual/2518830/Korg-Prologue-8.html?page=37

I counted a dozen ... yeah, that's a lot of firmware to develop and load onto the chips at manufacturing time.

I'm sure you were joking about the Raspberry Pi, but I can't resist a chance to be pedantic. The R-Pi is based on a Broadcom chip that has a lot of silicon dedicated to GPU functions. That's a lot of power and cost wasted on a function that isn't used in a synthesizer, and multiplying the waste by 12 would really be an issue.

Meanwhile, Korg seems to have selected the cheapest STM32 chips that can handle each task. Four front panel controllers are the STM32F030, which starts at $1.47 each. Six voice synthesizers are the STM32F401, which starts at $2.41 each. Then there are a couple of STM32F446 to coordinate voices, which are $3.22 each. Each one of those is 1/10 the cost of a Raspberry Pi. Some of the the STM32 variations even have 2D graphics acceleration to run the LCD displays more efficiently.

There are probably 10,000 different CPU options for modern electronics design, from companies like Analog Devices (SHARC and Blackfin), Freescale (Kinetis), XMOS, Texas Instruments (TMS320, Stellaris, MSP430), Microchip (PIC), and then many current revisions of classic eighties 8-bit processors as used in vintage hybrid analog synths. Some of them even use picoamps of current, making them great for long life on battery power.

Anyway, that's the end of my Public Service Announcement in 4, 3, 2, 1...



From dkantowitz at gmail.com  Tue Dec  2 02:54:33 2025
From: dkantowitz at gmail.com (David Kantowitz)
Date: Mon, 1 Dec 2025 17:54:33 -0800
Subject: [sdiy] Fet to short pedal input?
In-Reply-To: <B7AC2196-5363-41DD-B3B2-B716913C9E50@audiobanshee.com>
References: <LV8P222MB086185165F919557556BA913C4DFA@LV8P222MB0861.NAMP222.PROD.OUTLOOK.COM>
 <88669F3D-8FE2-480A-8E3F-B2E0231198D9@electricdruid.net>
 <SJ2P222MB08544A45AA7603B5E5BFD9FCC4DFA@SJ2P222MB0854.NAMP222.PROD.OUTLOOK.COM>
 <60DD7913-D1BD-4751-A885-C4BCEA46984A@audiobanshee.com>
 <81ed2801-72c6-4568-b27f-405236f05d7a@go2.pl>
 <408DCAF0-2AB0-47DD-8408-7A9F1D145E03@audiobanshee.com>
 <CAP92RBWNKx0JbeMHg7E5K7sJrZq4hTJP83TqrfC5BEh2gg+jOQ@mail.gmail.com>
 <KL1PR02MB6663235DFF5F9FD4C4AB8834B3DBA@KL1PR02MB6663.apcprd02.prod.outlook.com>
 <8ad5b1e0-6130-4700-b44f-e52c024d1e02@musictechnologiesgroup.com>
 <B7AC2196-5363-41DD-B3B2-B716913C9E50@audiobanshee.com>
Message-ID: <CAEfLrHFiK4zJs5p=_Ci0zV+4s9WvWFLCB9gxAKTk-NG8GG0EGA@mail.gmail.com>

On Mon, Dec 1, 2025 at 5:47?PM brianw <brianw at audiobanshee.com> wrote:

> On Dec 1, 2025, at 4:02 PM, grant wrote:
> > Geez, they have a whole truckload of STM32's in there. And I thought
> this was the Raspberry Pi musical instrument company...
> >
> > On 12/1/2025 5:00 AM, Sean Ellis wrote:
> >>
> >> https://www.manualslib.com/manual/2518830/Korg-Prologue-8.html?page=37
>
> I counted a dozen ... yeah, that's a lot of firmware to develop and load
> onto the chips at manufacturing time.
>
> I'm sure you were joking about the Raspberry Pi, but I can't resist a
> chance to be pedantic.


I think the wavestate, opsix, etc. cycle of synths had Raspi compute
modules in them.

>
>
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From mbryant at futurehorizons.com  Tue Dec  2 03:33:07 2025
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Tue, 2 Dec 2025 02:33:07 +0000
Subject: [sdiy] Fet to short pedal input?
In-Reply-To: <B7AC2196-5363-41DD-B3B2-B716913C9E50@audiobanshee.com>
References: <LV8P222MB086185165F919557556BA913C4DFA@LV8P222MB0861.NAMP222.PROD.OUTLOOK.COM>
 <88669F3D-8FE2-480A-8E3F-B2E0231198D9@electricdruid.net>
 <SJ2P222MB08544A45AA7603B5E5BFD9FCC4DFA@SJ2P222MB0854.NAMP222.PROD.OUTLOOK.COM>
 <60DD7913-D1BD-4751-A885-C4BCEA46984A@audiobanshee.com>
 <81ed2801-72c6-4568-b27f-405236f05d7a@go2.pl>
 <408DCAF0-2AB0-47DD-8408-7A9F1D145E03@audiobanshee.com>
 <CAP92RBWNKx0JbeMHg7E5K7sJrZq4hTJP83TqrfC5BEh2gg+jOQ@mail.gmail.com>
 <KL1PR02MB6663235DFF5F9FD4C4AB8834B3DBA@KL1PR02MB6663.apcprd02.prod.outlook.com>
 <8ad5b1e0-6130-4700-b44f-e52c024d1e02@musictechnologiesgroup.com>
 <B7AC2196-5363-41DD-B3B2-B716913C9E50@audiobanshee.com>
Message-ID: <CWLP265MB7132D32754BB4C76A6FB87EFDBD8A@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>

  *
Four front panel controllers are the STM32F030, which starts at $1.47 each.

Actually 40 cents tops in the volume Korg will use them at ?
Same with the other devices.

RPL don't discount for quantity so their devices work well in low volume applications.  But the RP2354 MCU with internal flash does still make sense in many applications.
________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of brianw <brianw at audiobanshee.com>
Sent: 02 December 2025 01:44
To: grant musictechnologiesgroup.com <grant at musictechnologiesgroup.com>
Cc: synth-diy at synth-diy.org <synth-diy at synth-diy.org>
Subject: Re: [sdiy] Fet to short pedal input?

On Dec 1, 2025, at 4:02 PM, grant wrote:
> Geez, they have a whole truckload of STM32's in there. And I thought this was the Raspberry Pi musical instrument company...
>
> On 12/1/2025 5:00 AM, Sean Ellis wrote:
>>
>> https://www.manualslib.com/manual/2518830/Korg-Prologue-8.html?page=37

I counted a dozen ... yeah, that's a lot of firmware to develop and load onto the chips at manufacturing time.

I'm sure you were joking about the Raspberry Pi, but I can't resist a chance to be pedantic. The R-Pi is based on a Broadcom chip that has a lot of silicon dedicated to GPU functions. That's a lot of power and cost wasted on a function that isn't used in a synthesizer, and multiplying the waste by 12 would really be an issue.

Meanwhile, Korg seems to have selected the cheapest STM32 chips that can handle each task. Four front panel controllers are the STM32F030, which starts at $1.47 each. Six voice synthesizers are the STM32F401, which starts at $2.41 each. Then there are a couple of STM32F446 to coordinate voices, which are $3.22 each. Each one of those is 1/10 the cost of a Raspberry Pi. Some of the the STM32 variations even have 2D graphics acceleration to run the LCD displays more efficiently.

There are probably 10,000 different CPU options for modern electronics design, from companies like Analog Devices (SHARC and Blackfin), Freescale (Kinetis), XMOS, Texas Instruments (TMS320, Stellaris, MSP430), Microchip (PIC), and then many current revisions of classic eighties 8-bit processors as used in vintage hybrid analog synths. Some of them even use picoamps of current, making them great for long life on battery power.

Anyway, that's the end of my Public Service Announcement in 4, 3, 2, 1...


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From grant at musictechnologiesgroup.com  Tue Dec  2 04:30:24 2025
From: grant at musictechnologiesgroup.com (grant musictechnologiesgroup.com)
Date: Tue, 2 Dec 2025 03:30:24 +0000
Subject: [sdiy] Fet to short pedal input?
In-Reply-To: <CAEfLrHFiK4zJs5p=_Ci0zV+4s9WvWFLCB9gxAKTk-NG8GG0EGA@mail.gmail.com>
References: <LV8P222MB086185165F919557556BA913C4DFA@LV8P222MB0861.NAMP222.PROD.OUTLOOK.COM>
 <88669F3D-8FE2-480A-8E3F-B2E0231198D9@electricdruid.net>
 <SJ2P222MB08544A45AA7603B5E5BFD9FCC4DFA@SJ2P222MB0854.NAMP222.PROD.OUTLOOK.COM>
 <60DD7913-D1BD-4751-A885-C4BCEA46984A@audiobanshee.com>
 <81ed2801-72c6-4568-b27f-405236f05d7a@go2.pl>
 <408DCAF0-2AB0-47DD-8408-7A9F1D145E03@audiobanshee.com>
 <CAP92RBWNKx0JbeMHg7E5K7sJrZq4hTJP83TqrfC5BEh2gg+jOQ@mail.gmail.com>
 <KL1PR02MB6663235DFF5F9FD4C4AB8834B3DBA@KL1PR02MB6663.apcprd02.prod.outlook.com>
 <8ad5b1e0-6130-4700-b44f-e52c024d1e02@musictechnologiesgroup.com>
 <B7AC2196-5363-41DD-B3B2-B716913C9E50@audiobanshee.com>
 <CAEfLrHFiK4zJs5p=_Ci0zV+4s9WvWFLCB9gxAKTk-NG8GG0EGA@mail.gmail.com>
Message-ID: <1f2cf0d9-52a7-43b4-bfa9-d601f32e0aaf@musictechnologiesgroup.com>


Yes, Modwave was the other one.

https://www.raspberrypi.com/success-stories/korg-synthesizers/


GB

On 12/1/2025 5:54 PM, David Kantowitz via Synth-diy wrote:


On Mon, Dec 1, 2025 at 5:47?PM brianw <brianw at audiobanshee.com<mailto:brianw at audiobanshee.com>> wrote:
On Dec 1, 2025, at 4:02 PM, grant wrote:
> Geez, they have a whole truckload of STM32's in there. And I thought this was the Raspberry Pi musical instrument company...
>
> On 12/1/2025 5:00 AM, Sean Ellis wrote:
>>
>> https://www.manualslib.com/manual/2518830/Korg-Prologue-8.html?page=37

I counted a dozen ... yeah, that's a lot of firmware to develop and load onto the chips at manufacturing time.

I'm sure you were joking about the Raspberry Pi, but I can't resist a chance to be pedantic.

I think the wavestate, opsix, etc. cycle of synths had Raspi compute modules in them.




________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org<mailto:Synth-diy at synth-diy.org>
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From don at till.com  Tue Dec  2 22:44:04 2025
From: don at till.com (Donald Tillman)
Date: Tue, 2 Dec 2025 13:44:04 -0800
Subject: [sdiy] DC-1 MHz, through-zero FM, controlled,
 oscillator without core capacitor
In-Reply-To: <CAGn5V--RBknCC8YUbD_H-eOn2JgTv6b=PAqm8B5jbSDfg98ugg@mail.gmail.com>
References: <CAGn5V--RBknCC8YUbD_H-eOn2JgTv6b=PAqm8B5jbSDfg98ugg@mail.gmail.com>
Message-ID: <74F14DB8-EEF9-4777-98FE-F0A4B9327F58@till.com>

That video is kind'a goofy.

Yes, the capacitance of a reverse-biased diode decreases with the reverse voltage.  "Varactor" diodes are optimized specifically for that, but any diode will do.

Two high frequency oscillators driving a modulator for an audio difference frequency is exactly how a Theremin works.  The frequencies are usually around 100Khz to 200Khz, and hand capacitance changes the tuning of one of the oscillators by a few percent.

It's also exactly how Morse code radio is received.  (Morse code radio does not transmit beeps.  The beeps are at the receiver where the local oscillator mixes with the received RF signal.)

And it's the basis for the quadrature thru-zero local oscillator in the Moog/Bode Frequency Shifter.

The 28 MHz this guy has is way, way too high for any useful audio work.  It covers the complete audio range in like a 0.04% RF frequency change.

  -- Don
--
Donald Tillman, Palo Alto, California
https://till.com

> On Nov 30, 2025, at 7:12?PM, cheater cheater via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
> I've been watching this video by Mr. Carlson:
> 
> https://www.youtube.com/watch?v=9r6ntkwAadY
> 
> It shows an old school diffuse red LED being used in reverse polarity
> as a varactor diode, and a setup using a potentiometer and that LED is
> used together in the same way as a multi-plate, variable, air
> capacitor such as a tuning capacitor taken out of a vintage AM radio.
> 
> The range of the simple circuit in the video is about 2 MHz. It occurs
> to me that one should be able to use a setup with two such oscillator
> cores, where one is being controlled, and the other one is at the
> middle of its range, together with some static low pass filters to
> extract only the fundamental sine waves, and a ring modulator, in
> order to get A-B mixing products to extract the full range and to
> center the range around 0 Hz and not around 27 MHz. Shaping to square
> wave, triangle, and other synthesizer waveforms is possible starting
> with a sine wave.
> 
> The low pass filters could probably require some form of capacitance,
> but maybe inductors are better suited. I think there might exist
> inexpensive premade brickwall filter modules for this sort of
> frequency range, but I'm not a radio guy.
> 
> The circuit is demonstrated to be voltage controllable using light, by
> using another LED, which can be fed constant current, dependent on
> voltage input. This setup makes the control circuit electrically
> decoupled from the oscillator and trivial to implement, essentially
> building a vactrol.
> 
> The stability will probably suck, but if you want stability go play on a VST.
> 
> The 2 MHz range provides the capability to divide the frequency by 128
> to achieve at least short-term stability, while numeric control could
> provide correction current for long term drift. This could be achieved
> by having a second copy of the oscillator running at a fixed
> frequency, thermally coupled to the oscillator under control. The
> second oscillator is input into a counter and control is exercised
> using a PID loop in feedback. The oscillator core is low component
> count and tiny in real estate, therefore it's easy to throw cores at a
> problem until it's solved.
> 
> I hope someone plays around with this idea since I don't have a good
> way of doing that myself at the moment.
> 
> I wonder if this would have a different sound than most typical VCOs,
> especially if exposed to FM. If you make one, please post line-in
> demos.
> 
> Cheers
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From don at till.com  Wed Dec  3 02:32:34 2025
From: don at till.com (Donald Tillman)
Date: Tue, 2 Dec 2025 17:32:34 -0800
Subject: [sdiy] DC-1 MHz, through-zero FM, controlled,
 oscillator without core capacitor
In-Reply-To: <CAGn5V--t1MWtWD5GC3cSCDHJZbxY+kBi4R2p4rZrQQJ6mhT=MA@mail.gmail.com>
References: <CAGn5V--RBknCC8YUbD_H-eOn2JgTv6b=PAqm8B5jbSDfg98ugg@mail.gmail.com>
 <CAGn5V-9_Vv8kxyEyj17g3fw42Br7ox1PX-UG6DgA363oUecqGQ@mail.gmail.com>
 <6ca6dc99ef73483de566c6f1a96255c9@richieburnett.co.uk>
 <CAGn5V--t1MWtWD5GC3cSCDHJZbxY+kBi4R2p4rZrQQJ6mhT=MA@mail.gmail.com>
Message-ID: <468577BB-6CB5-4DA8-8133-C243590A8917@till.com>

On Dec 1, 2025, at 8:21?AM, cheater cheater via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
> A PLL would mean completely digital control, wouldn't it?

PLLs are analog.  I'm not sure what you mean by "digital control".


> Do PLLs like that respond well to audio rate modulation?

PLLs are often used for FM radio demodulation, so yeah.


> Low bass on a Theremin sounds pretty good.
> https://www.youtube.com/watch?v=CgPgasgoVbU

That's an even goofier video!

Theremins can have a problem with very low notes because the two oscillators can sync up as their frequencies get really close.

So yeah a flip-flop on the output is reasonable feature.

  -- Don
--
Donald Tillman, Palo Alto, California
https://till.com

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From brianw at audiobanshee.com  Wed Dec  3 03:05:21 2025
From: brianw at audiobanshee.com (brianw)
Date: Tue, 2 Dec 2025 18:05:21 -0800
Subject: [sdiy] DC-1 MHz, through-zero FM, controlled,
 oscillator without core capacitor
In-Reply-To: <468577BB-6CB5-4DA8-8133-C243590A8917@till.com>
References: <CAGn5V--RBknCC8YUbD_H-eOn2JgTv6b=PAqm8B5jbSDfg98ugg@mail.gmail.com>
 <CAGn5V-9_Vv8kxyEyj17g3fw42Br7ox1PX-UG6DgA363oUecqGQ@mail.gmail.com>
 <6ca6dc99ef73483de566c6f1a96255c9@richieburnett.co.uk>
 <CAGn5V--t1MWtWD5GC3cSCDHJZbxY+kBi4R2p4rZrQQJ6mhT=MA@mail.gmail.com>
 <468577BB-6CB5-4DA8-8133-C243590A8917@till.com>
Message-ID: <AC48863D-F607-4B9A-9818-12A05868FF4F@audiobanshee.com>



On Dec 2, 2025, at 5:32 PM, Donald Tillman wrote:
> On Dec 1, 2025, at 8:21?AM, cheater cheater wrote:
>> 
>> A PLL would mean completely digital control, wouldn't it?
> 
> PLLs are analog.  I'm not sure what you mean by "digital control".

PLLs can be implemented as either analog or digital.

In fact, some Texas Instruments TMS320 DSP chips have both DPLL (digital) and APLL (analog). Their PLL implementations are described such that the analog PLL is more noise tolerant and has less long-term jitter, and thus they recommend it when interfacing to USB.

I certainly don't know what the difference is between digital and analog PLL, but the differences are useful enough to implement both on the same chip (and I happen to find it interesting that an "analog" PLL can be implemented on a Digital Signal Processor die).

Brian Willoughby



From lijon at kymatica.com  Wed Dec  3 09:09:35 2025
From: lijon at kymatica.com (Jonatan Liljedahl)
Date: Wed, 3 Dec 2025 09:09:35 +0100
Subject: [sdiy] DC-1 MHz, through-zero FM, controlled,
 oscillator without core capacitor
In-Reply-To: <74F14DB8-EEF9-4777-98FE-F0A4B9327F58@till.com>
References: <CAGn5V--RBknCC8YUbD_H-eOn2JgTv6b=PAqm8B5jbSDfg98ugg@mail.gmail.com>
 <74F14DB8-EEF9-4777-98FE-F0A4B9327F58@till.com>
Message-ID: <CALfiFhBKNzsYmT+ErTmwGAFBUsBmCfC+B8dR+cNaAJPEuYF-1Q@mail.gmail.com>

tis 2 dec. 2025 kl. 22:49 skrev Donald Tillman <don at till.com>:

>
> It's also exactly how Morse code radio is received.  (Morse code radio
> does not transmit beeps.  The beeps are at the receiver where the local
> oscillator mixes with the received RF signal.)
>

Not only morse code (CW) but also single side-band transmission (SSB),
which is standard in HF radio. It uses half the bandwidth of AM, and also
potentially it needs less power than AM since the carrier doesn't have to
be transmitted.

>
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From cheater00social at gmail.com  Wed Dec  3 09:46:24 2025
From: cheater00social at gmail.com (cheater cheater)
Date: Wed, 3 Dec 2025 09:46:24 +0100
Subject: [sdiy] DC-1 MHz, through-zero FM, controlled,
 oscillator without core capacitor
In-Reply-To: <CALfiFhBKNzsYmT+ErTmwGAFBUsBmCfC+B8dR+cNaAJPEuYF-1Q@mail.gmail.com>
References: <CAGn5V--RBknCC8YUbD_H-eOn2JgTv6b=PAqm8B5jbSDfg98ugg@mail.gmail.com>
 <74F14DB8-EEF9-4777-98FE-F0A4B9327F58@till.com>
 <CALfiFhBKNzsYmT+ErTmwGAFBUsBmCfC+B8dR+cNaAJPEuYF-1Q@mail.gmail.com>
Message-ID: <CAGn5V-8AZ2V9sfPQfUi9Y06=WcxjBPDmvN756KA+x0qg8soAwQ@mail.gmail.com>

what is the minimal analog implementation of a PLL that would be
useful for taming a varactor based oscillator, while retaining ability
to do audio rate frequency modulation?

On Wed, Dec 3, 2025 at 9:09?AM Jonatan Liljedahl <lijon at kymatica.com> wrote:
>
> tis 2 dec. 2025 kl. 22:49 skrev Donald Tillman <don at till.com>:
>>
>>
>> It's also exactly how Morse code radio is received.  (Morse code radio does not transmit beeps.  The beeps are at the receiver where the local oscillator mixes with the received RF signal.)
>
>
> Not only morse code (CW) but also single side-band transmission (SSB), which is standard in HF radio. It uses half the bandwidth of AM, and also potentially it needs less power than AM since the carrier doesn't have to be transmitted.


From synth at schmitzbits.de  Wed Dec  3 11:43:57 2025
From: synth at schmitzbits.de (synth at schmitzbits.de)
Date: Wed, 3 Dec 2025 10:43:57 +0000
Subject: [sdiy] DC-1 MHz, through-zero FM, controlled,
 oscillator without core capacitor
In-Reply-To: <468577BB-6CB5-4DA8-8133-C243590A8917@till.com>
References: <CAGn5V--RBknCC8YUbD_H-eOn2JgTv6b=PAqm8B5jbSDfg98ugg@mail.gmail.com>
 <CAGn5V-9_Vv8kxyEyj17g3fw42Br7ox1PX-UG6DgA363oUecqGQ@mail.gmail.com>
 <6ca6dc99ef73483de566c6f1a96255c9@richieburnett.co.uk>
 <CAGn5V--t1MWtWD5GC3cSCDHJZbxY+kBi4R2p4rZrQQJ6mhT=MA@mail.gmail.com>
 <468577BB-6CB5-4DA8-8133-C243590A8917@till.com>
Message-ID: <BEZP281MB1973A8DB20D3A82B25CA881DD3D9A@BEZP281MB1973.DEUP281.PROD.OUTLOOK.COM>

>PLLs are analog.  I'm not sure what you mean by "digital control".

I think what he refers to is that a PLLs often has a frequency divider that is digitally controlled.

Cheers,
 Ren?

________________________________
Von: Synth-diy <synth-diy-bounces at synth-diy.org> im Auftrag von Donald Tillman <don at till.com>
Gesendet: Mittwoch, 3. Dezember 2025 02:32
An: cheater cheater <cheater00social at gmail.com>
Cc: rburnett at richieburnett.co.uk <rburnett at richieburnett.co.uk>; synth-diy <synth-diy at synth-diy.org>
Betreff: Re: [sdiy] DC-1 MHz, through-zero FM, controlled, oscillator without core capacitor

On Dec 1, 2025, at 8:21?AM, cheater cheater via Synth-diy <synth-diy at synth-diy.org> wrote:

A PLL would mean completely digital control, wouldn't it?

PLLs are analog.  I'm not sure what you mean by "digital control".




Do PLLs like that respond well to audio rate modulation?

PLLs are often used for FM radio demodulation, so yeah.


Low bass on a Theremin sounds pretty good.
https://www.youtube.com/watch?v=CgPgasgoVbU

That's an even goofier video!

Theremins can have a problem with very low notes because the two oscillators can sync up as their frequencies get really close.

So yeah a flip-flop on the output is reasonable feature.

  -- Don
--
Donald Tillman, Palo Alto, California
https://till.com

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From gordonjcp at gjcp.net  Thu Dec  4 10:38:59 2025
From: gordonjcp at gjcp.net (Gordonjcp)
Date: Thu, 4 Dec 2025 09:38:59 +0000
Subject: [sdiy] DC-1 MHz, through-zero FM, controlled,
 oscillator without core capacitor
In-Reply-To: <CAGn5V-8AZ2V9sfPQfUi9Y06=WcxjBPDmvN756KA+x0qg8soAwQ@mail.gmail.com>
References: <CAGn5V--RBknCC8YUbD_H-eOn2JgTv6b=PAqm8B5jbSDfg98ugg@mail.gmail.com>
 <74F14DB8-EEF9-4777-98FE-F0A4B9327F58@till.com>
 <CALfiFhBKNzsYmT+ErTmwGAFBUsBmCfC+B8dR+cNaAJPEuYF-1Q@mail.gmail.com>
 <CAGn5V-8AZ2V9sfPQfUi9Y06=WcxjBPDmvN756KA+x0qg8soAwQ@mail.gmail.com>
Message-ID: <20251204093859.GA26708@gjcp.net>

On Wed, Dec 03, 2025 at 09:46:24AM +0100, cheater cheater via Synth-diy wrote:
> what is the minimal analog implementation of a PLL that would be
> useful for taming a varactor based oscillator, while retaining ability
> to do audio rate frequency modulation?
> 

Ye Olde CD4046 I guess? Have you ever looked at how the oscillator in an EDP Wasp/Gnat works? The touch keyboard generates a digital clock that a 4046 PLL locks to, with the PLL generating the squarewave directly and its control voltage setting the ramp current for the sawtooth generator very much like a Juno DCO. The PWMed output is generated from the saw, as you'd expect.

I guess the audio rate modulation would be dependent on the loop time constant. The loop control voltage is lowpassed so that it doesn't become unstable. Think in terms of tuning a PID, you don't want it to respond too fast or it'll overshoot and you don't want it to respond too slow or it'll take forever to settle.

-- 
Gordonjcp


From list at mikebeauchamp.com  Sat Dec 13 06:55:30 2025
From: list at mikebeauchamp.com (Mike Beauchamp)
Date: Sat, 13 Dec 2025 00:55:30 -0500
Subject: [sdiy] SMT transistor for white noise?
Message-ID: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>

I'm noticing my latest batch of MMBT3904 by ONSEMI are barely creating 
any white noise, requiring about 8000x gain to get up to +/- 5V.

Previous batches of the MMBT3904 only required about 500x gain to get up 
to +/- 5V. When I was using TH 2N3904, I think the gain required was 
only about 200x.

This much gain is also making something on the board (ceramic caps, the 
transistor itself?) pretty microphonic and tapping on the board is now 
audible.

Before I order a few dozen samples of different transistors off digikey 
to test, I'm wondering if anybody had any go-to parts for SMT 
transistors that are still noisy?

Mike


From jschwich53 at comcast.net  Sat Dec 13 07:45:54 2025
From: jschwich53 at comcast.net (Jay Schwichtenberg)
Date: Fri, 12 Dec 2025 22:45:54 -0800 (PST)
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
References: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
Message-ID: <849764329.165727.1765608354401@connect.xfinity.com>

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From modular at go2.pl  Sat Dec 13 09:06:39 2025
From: modular at go2.pl (Roman)
Date: Sat, 13 Dec 2025 09:06:39 +0100
Subject: [sdiy] ODP:  SMT transistor for white noise?
In-Reply-To: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
References: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
Message-ID: <qdjrk7884oa6d46qb1fro120.1765613199727@email.android.com>

IMHO the best SMD transistor for noise is tiny microcontroller in SOT23-6 running LFSR.

Roman 

---- U?ytkownik Mike Beauchamp napisa? ----

>I'm noticing my latest batch of MMBT3904 by ONSEMI are barely creating 
>any white noise, requiring about 8000x gain to get up to +/- 5V.
>
>Previous batches of the MMBT3904 only required about 500x gain to get up 
>to +/- 5V. When I was using TH 2N3904, I think the gain required was 
>only about 200x.
>
>This much gain is also making something on the board (ceramic caps, the 
>transistor itself?) pretty microphonic and tapping on the board is now 
>audible.
>
>Before I order a few dozen samples of different transistors off digikey 
>to test, I'm wondering if anybody had any go-to parts for SMT 
>transistors that are still noisy?
>
>Mike
>
>________________________________________________________
>This is the Synth-diy mailing list
>Submit email to: Synth-diy at synth-diy.org
>View archive at: https://synth-diy.org/pipermail/synth-diy/
>Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>Selling or trading? Use marketplace at synth-diy.org
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From gordonjcp at gjcp.net  Sat Dec 13 11:32:28 2025
From: gordonjcp at gjcp.net (Gordonjcp)
Date: Sat, 13 Dec 2025 10:32:28 +0000
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
References: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
Message-ID: <20251213103228.GA28738@gjcp.net>

On Sat, Dec 13, 2025 at 12:55:30AM -0500, Mike Beauchamp wrote:
> I'm noticing my latest batch of MMBT3904 by ONSEMI are barely creating any
> white noise, requiring about 8000x gain to get up to +/- 5V.
> 
> Previous batches of the MMBT3904 only required about 500x gain to get up to
> +/- 5V. When I was using TH 2N3904, I think the gain required was only about
> 200x.

I'm guessing you've got cheap Chinese ones this time round. They're far too high quality to use as noise sources.

You need to pay a bit extra to get American-made dodgy counterfeit components for this.

-- 
Gordonjcp

From mbryant at futurehorizons.com  Sat Dec 13 12:11:54 2025
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Sat, 13 Dec 2025 11:11:54 +0000
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <20251213103228.GA28738@gjcp.net>
References: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
 <20251213103228.GA28738@gjcp.net>
Message-ID: <CWLP265MB71325DE00E782DC7A6F97EA4DBAFA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>

Too true ?   A large percentage of the world's small signal transistors now come from a huge fab in Chongqing and they just brand them to whatever their client wants.

Small power devices may be your best bet for more consistent noise as they are larger area and so will have a few more defects in them.
________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Gordonjcp <gordonjcp at gjcp.net>
Sent: 13 December 2025 10:32
To: synth-diy at synth-diy.org <synth-diy at synth-diy.org>
Subject: Re: [sdiy] SMT transistor for white noise?

On Sat, Dec 13, 2025 at 12:55:30AM -0500, Mike Beauchamp wrote:
> I'm noticing my latest batch of MMBT3904 by ONSEMI are barely creating any
> white noise, requiring about 8000x gain to get up to +/- 5V.
>
> Previous batches of the MMBT3904 only required about 500x gain to get up to
> +/- 5V. When I was using TH 2N3904, I think the gain required was only about
> 200x.

I'm guessing you've got cheap Chinese ones this time round. They're far too high quality to use as noise sources.

You need to pay a bit extra to get American-made dodgy counterfeit components for this.

--
Gordonjcp
________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org
View archive at: https://synth-diy.org/pipermail/synth-diy/
Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
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From pfperry at melbpc.org.au  Sat Dec 13 13:32:10 2025
From: pfperry at melbpc.org.au (Paul Perry)
Date: Sat, 13 Dec 2025 23:32:10 +1100
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <CWLP265MB71325DE00E782DC7A6F97EA4DBAFA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
References: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
 <20251213103228.GA28738@gjcp.net>
 <CWLP265MB71325DE00E782DC7A6F97EA4DBAFA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <CAA79VLrsW-Le=hUMe+Enb4Ypt58W5570Lh9WXBYiFoWPDBQc-w@mail.gmail.com>

Is it possible to simply amplify the thermal noise in a high value resistor?
paul perry Melbourne Australia

On Sat, Dec 13, 2025 at 10:15?PM Mike Bryant <mbryant at futurehorizons.com>
wrote:

> Too true ?   A large percentage of the world's small signal transistors
> now come from a huge fab in Chongqing and they just brand them to whatever
> their client wants.
>
> Small power devices may be your best bet for more consistent noise as they
> are larger area and so will have a few more defects in them.
> ------------------------------
> *From:* Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of
> Gordonjcp <gordonjcp at gjcp.net>
> *Sent:* 13 December 2025 10:32
> *To:* synth-diy at synth-diy.org <synth-diy at synth-diy.org>
> *Subject:* Re: [sdiy] SMT transistor for white noise?
>
> On Sat, Dec 13, 2025 at 12:55:30AM -0500, Mike Beauchamp wrote:
> > I'm noticing my latest batch of MMBT3904 by ONSEMI are barely creating
> any
> > white noise, requiring about 8000x gain to get up to +/- 5V.
> >
> > Previous batches of the MMBT3904 only required about 500x gain to get up
> to
> > +/- 5V. When I was using TH 2N3904, I think the gain required was only
> about
> > 200x.
>
> I'm guessing you've got cheap Chinese ones this time round. They're far
> too high quality to use as noise sources.
>
> You need to pay a bit extra to get American-made dodgy counterfeit
> components for this.
>
> --
> Gordonjcp
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
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From mr at analogue.org  Sat Dec 13 13:50:18 2025
From: mr at analogue.org (Mattias Rickardsson)
Date: Sat, 13 Dec 2025 13:50:18 +0100
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <CAA79VLrsW-Le=hUMe+Enb4Ypt58W5570Lh9WXBYiFoWPDBQc-w@mail.gmail.com>
References: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
 <20251213103228.GA28738@gjcp.net>
 <CWLP265MB71325DE00E782DC7A6F97EA4DBAFA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAA79VLrsW-Le=hUMe+Enb4Ypt58W5570Lh9WXBYiFoWPDBQc-w@mail.gmail.com>
Message-ID: <CAP92RBXH2udC6-eizq80EyzdB4-LFbcmMajRuhovb=qHcHE8SQ@mail.gmail.com>

Den l?r 13 dec. 2025 13:34Paul Perry via Synth-diy <synth-diy at synth-diy.org>
skrev:

> Is it possible to simply amplify the thermal noise in a high value
> resistor?
> paul perry Melbourne Australia
>

And/or the noise of a noisy op-amp in a high-gain setting?

/mr

>
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From mbryant at futurehorizons.com  Sat Dec 13 14:54:39 2025
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Sat, 13 Dec 2025 13:54:39 +0000
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <CAP92RBXH2udC6-eizq80EyzdB4-LFbcmMajRuhovb=qHcHE8SQ@mail.gmail.com>
References: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
 <20251213103228.GA28738@gjcp.net>
 <CWLP265MB71325DE00E782DC7A6F97EA4DBAFA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAA79VLrsW-Le=hUMe+Enb4Ypt58W5570Lh9WXBYiFoWPDBQc-w@mail.gmail.com>
 <CAP92RBXH2udC6-eizq80EyzdB4-LFbcmMajRuhovb=qHcHE8SQ@mail.gmail.com>
Message-ID: <1e46e322-0c4c-4d27-9686-a74af9695f8f@email.android.com>

Thinking back, in the 70s Zener diodes gave better noise than transistors

On 13 Dec 2025 12:52, Mattias Rickardsson <mr at analogue.org> wrote:


Den l?r 13 dec. 2025 13:34Paul Perry via Synth-diy <synth-diy at synth-diy.org<mailto:synth-diy at synth-diy.org>> skrev:
Is it possible to simply amplify the thermal noise in a high value resistor?
paul perry Melbourne Australia

And/or the noise of a noisy op-amp in a high-gain setting?

/mr
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From brothertheo2014 at gmail.com  Sat Dec 13 15:35:02 2025
From: brothertheo2014 at gmail.com (Brother Theo)
Date: Sat, 13 Dec 2025 09:35:02 -0500
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <1e46e322-0c4c-4d27-9686-a74af9695f8f@email.android.com>
References: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
 <20251213103228.GA28738@gjcp.net>
 <CWLP265MB71325DE00E782DC7A6F97EA4DBAFA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAA79VLrsW-Le=hUMe+Enb4Ypt58W5570Lh9WXBYiFoWPDBQc-w@mail.gmail.com>
 <CAP92RBXH2udC6-eizq80EyzdB4-LFbcmMajRuhovb=qHcHE8SQ@mail.gmail.com>
 <1e46e322-0c4c-4d27-9686-a74af9695f8f@email.android.com>
Message-ID: <CA+K2+DK8e=6mcGfxand9bHE+9Cg_2oRuqs_-H8XVU2a9um=ZuQ@mail.gmail.com>

I switched to the 2 transistor noise circuit and have had zero issues
since. The Future Retro 777 re-release uses that circuit.



On Sat, Dec 13, 2025 at 8:57?AM Mike Bryant <mbryant at futurehorizons.com>
wrote:

> Thinking back, in the 70s Zener diodes gave better noise than transistors
>
> On 13 Dec 2025 12:52, Mattias Rickardsson <mr at analogue.org> wrote:
>
>
> Den l?r 13 dec. 2025 13:34Paul Perry via Synth-diy <
> synth-diy at synth-diy.org> skrev:
>
>> Is it possible to simply amplify the thermal noise in a high value
>> resistor?
>> paul perry Melbourne Australia
>>
>
> And/or the noise of a noisy op-amp in a high-gain setting?
>
> /mr
>
>> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>


-- 
Timothy Ressel
909-423-5962
FutureRetro Synthesizers
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From tom at electricdruid.net  Sat Dec 13 16:46:44 2025
From: tom at electricdruid.net (Tom Wiltshire)
Date: Sat, 13 Dec 2025 15:46:44 +0000
Subject: [sdiy] ODP:  SMT transistor for white noise?
In-Reply-To: <qdjrk7884oa6d46qb1fro120.1765613199727@email.android.com>
References: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
 <qdjrk7884oa6d46qb1fro120.1765613199727@email.android.com>
Message-ID: <531DB332-2BA0-47C9-A71B-84FB0D529EF5@electricdruid.net>



> On 13 Dec 2025, at 08:06, Roman via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
> IMHO the best SMD transistor for noise is tiny microcontroller in SOT23-6 running LFSR.
> 
> Roman

I was thinking exactly the same thing, Roman!

You get a 2.5V average output level so the required gain goes way down and that saves picking up mains hum, extraneous noises, etc etc. Plus you get reliably white output from *every* device, not just some of 'em. There was a reason we moved away from transistor noise sources back in the day...;)

Tom

From gordonjcp at gjcp.net  Sat Dec 13 20:22:48 2025
From: gordonjcp at gjcp.net (Gordonjcp)
Date: Sat, 13 Dec 2025 19:22:48 +0000
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <CWLP265MB71325DE00E782DC7A6F97EA4DBAFA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
References: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
 <20251213103228.GA28738@gjcp.net>
 <CWLP265MB71325DE00E782DC7A6F97EA4DBAFA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <20251213192248.GA30200@gjcp.net>

On Sat, Dec 13, 2025 at 11:11:54AM +0000, Mike Bryant wrote:
> Too true ?   A large percentage of the world's small signal transistors now come from a huge fab in Chongqing and they just brand them to whatever their client wants.
> 

Many years ago I bought a bag of something like 500 of the cheapest Chinesiest BC548-wannabes from Some Dude In Shenzen On eBay, expecting to maybe hand-match a couple of sets of a dozen reasonably close ones for filters.

Nope.

Any two you pulled out of the bag at random would have the same Vbe down to *microvolts*.

So that was a quicker evening than I anticipated.

-- 
Gordonjcp


From ijfritz at comcast.net  Sat Dec 13 20:53:57 2025
From: ijfritz at comcast.net (Ian Fritz)
Date: Sat, 13 Dec 2025 12:53:57 -0700
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <20251213192248.GA30200@gjcp.net>
References: <20251213192248.GA30200@gjcp.net>
Message-ID: <509C773B-6FB9-4303-9780-F62012F813CE@comcast.net>

Do they have these in monolithic pair packages?

Ian

> On Dec 13, 2025, at 12:27?PM, Gordonjcp <gordonjcp at gjcp.net> wrote:
> 
> ?On Sat, Dec 13, 2025 at 11:11:54AM +0000, Mike Bryant wrote:
>> Too true ?   A large percentage of the world's small signal transistors now come from a huge fab in Chongqing and they just brand them to whatever their client wants.
>> 
> 
> Many years ago I bought a bag of something like 500 of the cheapest Chinesiest BC548-wannabes from Some Dude In Shenzen On eBay, expecting to maybe hand-match a couple of sets of a dozen reasonably close ones for filters.
> 
> Nope.
> 
> Any two you pulled out of the bag at random would have the same Vbe down to *microvolts*.
> 
> So that was a quicker evening than I anticipated.
> 
> --
> Gordonjcp
> 
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org



From scottbernardi55 at gmail.com  Sat Dec 13 21:06:46 2025
From: scottbernardi55 at gmail.com (Scott Bernardi)
Date: Sat, 13 Dec 2025 12:06:46 -0800
Subject: [sdiy] Tri to Saw converter produces a weird waveform
Message-ID: <CAM-tPNP4CSLS-Z0inuEyaidqiheiCeWDOpOHr5N4VcxAYmusLg@mail.gmail.com>

I built a tri core vco and used a typical method to convert the triangle to
a saw using the invert - noninvert of the triangle and adding the square
back in.  Schematic and the waveforms I get are on this page:
Weird Saw <https://www.bernacomp.com/elec/og2/weird-saw.html>

Any ideas what's going on and how to correct it?
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From lijon at kymatica.com  Sat Dec 13 21:28:11 2025
From: lijon at kymatica.com (Jonatan Liljedahl)
Date: Sat, 13 Dec 2025 21:28:11 +0100
Subject: [sdiy] Tri to Saw converter produces a weird waveform
In-Reply-To: <CAM-tPNP4CSLS-Z0inuEyaidqiheiCeWDOpOHr5N4VcxAYmusLg@mail.gmail.com>
References: <CAM-tPNP4CSLS-Z0inuEyaidqiheiCeWDOpOHr5N4VcxAYmusLg@mail.gmail.com>
Message-ID: <CALfiFhB1+WXL7Rt8EawhWj4HsT+0P_ozYie8aSYZxMaupW06Wg@mail.gmail.com>

Just an idea: the first opamp is clipping due to common mode input voltage
outside range? TL072 on +/-12V only handles about -8 to +10 IIRC.

/Jonatan
http://kymatica.com


l?r 13 dec. 2025 kl. 21:10 skrev Scott Bernardi via Synth-diy <
synth-diy at synth-diy.org>:

> I built a tri core vco and used a typical method to convert the triangle
> to a saw using the invert - noninvert of the triangle and adding the square
> back in.  Schematic and the waveforms I get are on this page:
> Weird Saw <https://www.bernacomp.com/elec/og2/weird-saw.html>
>
> Any ideas what's going on and how to correct it?
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
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From don at till.com  Sat Dec 13 21:41:34 2025
From: don at till.com (Donald Tillman)
Date: Sat, 13 Dec 2025 12:41:34 -0800
Subject: [sdiy] Tri to Saw converter produces a weird waveform
In-Reply-To: <CAM-tPNP4CSLS-Z0inuEyaidqiheiCeWDOpOHr5N4VcxAYmusLg@mail.gmail.com>
References: <CAM-tPNP4CSLS-Z0inuEyaidqiheiCeWDOpOHr5N4VcxAYmusLg@mail.gmail.com>
Message-ID: <AC301D13-A146-4302-9492-BC5EE62BA340@till.com>

On Dec 13, 2025, at 12:06?PM, Scott Bernardi via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
> I built a tri core vco and used a typical method to convert the triangle to a saw using the invert - noninvert of the triangle and adding the square back in.  Schematic and the waveforms I get are on this page:
> Weird Saw <https://www.bernacomp.com/elec/og2/weird-saw.html>
> 
> Any ideas what's going on and how to correct it?

The 2N7000 has a parasitic diode between the drain and the source, so it will start conducting if the drain goes more than 0.6V negative.

  -- Don
--
Donald Tillman, Palo Alto, California
https://till.com
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From phil.macphail at liivatera.com  Sat Dec 13 21:44:21 2025
From: phil.macphail at liivatera.com (Phil Macphail)
Date: Sat, 13 Dec 2025 22:44:21 +0200
Subject: [sdiy] Tri to Saw converter produces a weird waveform
In-Reply-To: <CAM-tPNP4CSLS-Z0inuEyaidqiheiCeWDOpOHr5N4VcxAYmusLg@mail.gmail.com>
References: <CAM-tPNP4CSLS-Z0inuEyaidqiheiCeWDOpOHr5N4VcxAYmusLg@mail.gmail.com>
Message-ID: <96AD135A-E788-42E9-9C43-2B868F7A37B0@liivatera.com>

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From list at mikebeauchamp.com  Sat Dec 13 22:05:58 2025
From: list at mikebeauchamp.com (Mike Beauchamp)
Date: Sat, 13 Dec 2025 16:05:58 -0500
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <CA+K2+DK8e=6mcGfxand9bHE+9Cg_2oRuqs_-H8XVU2a9um=ZuQ@mail.gmail.com>
References: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
 <20251213103228.GA28738@gjcp.net>
 <CWLP265MB71325DE00E782DC7A6F97EA4DBAFA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAA79VLrsW-Le=hUMe+Enb4Ypt58W5570Lh9WXBYiFoWPDBQc-w@mail.gmail.com>
 <CAP92RBXH2udC6-eizq80EyzdB4-LFbcmMajRuhovb=qHcHE8SQ@mail.gmail.com>
 <1e46e322-0c4c-4d27-9686-a74af9695f8f@email.android.com>
 <CA+K2+DK8e=6mcGfxand9bHE+9Cg_2oRuqs_-H8XVU2a9um=ZuQ@mail.gmail.com>
Message-ID: <b1e7a18e-6160-401e-8078-fa69eb6952cf@mikebeauchamp.com>

On 2025-12-13 09:35, Brother Theo via Synth-diy wrote:
> I switched to the 2 transistor noise circuit and have had zero issues 
> since. The Future Retro 777 re-release uses that circuit.

Hi Timothy, doing some duckduckgo-ing, I found a few...

https://www.edn.com/simple-white-noise-generator/

https://www.nutsvolts.com/magazine/article/bipolar_transistor_cookbook_part_5 
(figure 20)


The EDN article is interesting. Seems like the second transistor is just 
the amplification stage and the increased noise level is because of the 
addition of C1. I don't understand the function of C1.. time to get out 
the breadboard.

Mike

From scottbernardi55 at gmail.com  Sun Dec 14 00:03:11 2025
From: scottbernardi55 at gmail.com (Scott Bernardi)
Date: Sat, 13 Dec 2025 15:03:11 -0800
Subject: [sdiy] Tri to Saw converter produces a weird waveform
In-Reply-To: <AC301D13-A146-4302-9492-BC5EE62BA340@till.com>
References: <CAM-tPNP4CSLS-Z0inuEyaidqiheiCeWDOpOHr5N4VcxAYmusLg@mail.gmail.com>
 <AC301D13-A146-4302-9492-BC5EE62BA340@till.com>
Message-ID: <CAM-tPNOAsC=wZb6WBsVQtirb2awq3pDWf0zNeyLq6XN-n519hg@mail.gmail.com>

Yep, that was it. I had to go back to an npn transistor with a series diode
and resistor driving the base (I was hoping the MOSFET would give me a
sharper edge on the top of the sawtooth. It's a bit rounded with the npn).

On Sat, Dec 13, 2025 at 12:41?PM Donald Tillman <don at till.com> wrote:

> On Dec 13, 2025, at 12:06?PM, Scott Bernardi via Synth-diy <
> synth-diy at synth-diy.org> wrote:
>
>
> I built a tri core vco and used a typical method to convert the triangle
> to a saw using the invert - noninvert of the triangle and adding the square
> back in.  Schematic and the waveforms I get are on this page:
> Weird Saw <https://www.bernacomp.com/elec/og2/weird-saw.html>
>
> Any ideas what's going on and how to correct it?
>
>
> The 2N7000 has a parasitic diode between the drain and the source, so it
> will start conducting if the drain goes more than 0.6V negative.
>
>   -- Don
> --
> Donald Tillman, Palo Alto, California
> https://till.com
>
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From jschwich53 at comcast.net  Sun Dec 14 01:48:38 2025
From: jschwich53 at comcast.net (Jay Schwichtenberg)
Date: Sat, 13 Dec 2025 16:48:38 -0800
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <b1e7a18e-6160-401e-8078-fa69eb6952cf@mikebeauchamp.com>
References: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
 <20251213103228.GA28738@gjcp.net>
 <CWLP265MB71325DE00E782DC7A6F97EA4DBAFA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAA79VLrsW-Le=hUMe+Enb4Ypt58W5570Lh9WXBYiFoWPDBQc-w@mail.gmail.com>
 <CAP92RBXH2udC6-eizq80EyzdB4-LFbcmMajRuhovb=qHcHE8SQ@mail.gmail.com>
 <1e46e322-0c4c-4d27-9686-a74af9695f8f@email.android.com>
 <CA+K2+DK8e=6mcGfxand9bHE+9Cg_2oRuqs_-H8XVU2a9um=ZuQ@mail.gmail.com>
 <b1e7a18e-6160-401e-8078-fa69eb6952cf@mikebeauchamp.com>
Message-ID: <eea35985-c3eb-455f-a58b-ab572cb59b9e@comcast.net>

I've used the EDN noise circuit at least 3 times and it has worked just 
fine. I always socket the noise transistor and select it. I bought a bag 
of 500 2N3904 transistors (for 1 cent each) about 15 years ago.

Thing about LFSRs is they are usually pseudo random. They typically 
contain small sections of noise that repetitive. In most case that is 
good enough but not truly random. In order to get truly random noise 
digitally it can be somewhat complicated.

Jay S.

On 12/13/2025 1:05 PM, Mike Beauchamp wrote:
> On 2025-12-13 09:35, Brother Theo via Synth-diy wrote:
>> I switched to the 2 transistor noise circuit and have had zero issues 
>> since. The Future Retro 777 re-release uses that circuit.
>
> Hi Timothy, doing some duckduckgo-ing, I found a few...
>
> https://www.edn.com/simple-white-noise-generator/
>
> https://www.nutsvolts.com/magazine/article/bipolar_transistor_cookbook_part_5 
> (figure 20)
>
>
> The EDN article is interesting. Seems like the second transistor is 
> just the amplification stage and the increased noise level is because 
> of the addition of C1. I don't understand the function of C1.. time to 
> get out the breadboard.
>
> Mike
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org

From jschwich53 at comcast.net  Sun Dec 14 01:59:38 2025
From: jschwich53 at comcast.net (Jay Schwichtenberg)
Date: Sat, 13 Dec 2025 16:59:38 -0800
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <b1e7a18e-6160-401e-8078-fa69eb6952cf@mikebeauchamp.com>
References: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
 <20251213103228.GA28738@gjcp.net>
 <CWLP265MB71325DE00E782DC7A6F97EA4DBAFA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAA79VLrsW-Le=hUMe+Enb4Ypt58W5570Lh9WXBYiFoWPDBQc-w@mail.gmail.com>
 <CAP92RBXH2udC6-eizq80EyzdB4-LFbcmMajRuhovb=qHcHE8SQ@mail.gmail.com>
 <1e46e322-0c4c-4d27-9686-a74af9695f8f@email.android.com>
 <CA+K2+DK8e=6mcGfxand9bHE+9Cg_2oRuqs_-H8XVU2a9um=ZuQ@mail.gmail.com>
 <b1e7a18e-6160-401e-8078-fa69eb6952cf@mikebeauchamp.com>
Message-ID: <5bea33a9-4645-430f-b6be-3939a2b67599@comcast.net>

Looking at the EDN schematic again I think there is an error. Think C1 
should go from Q1's emitter and ground, not emitter and +12. I built 
mine with C1 going to ground.

Jay S.

On 12/13/2025 1:05 PM, Mike Beauchamp wrote:
> On 2025-12-13 09:35, Brother Theo via Synth-diy wrote:
>> I switched to the 2 transistor noise circuit and have had zero issues 
>> since. The Future Retro 777 re-release uses that circuit.
>
> Hi Timothy, doing some duckduckgo-ing, I found a few...
>
> https://www.edn.com/simple-white-noise-generator/
>
> https://www.nutsvolts.com/magazine/article/bipolar_transistor_cookbook_part_5 
> (figure 20)
>
>
> The EDN article is interesting. Seems like the second transistor is 
> just the amplification stage and the increased noise level is because 
> of the addition of C1. I don't understand the function of C1.. time to 
> get out the breadboard.
>
> Mike
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org

From tom at electricdruid.net  Sun Dec 14 02:10:09 2025
From: tom at electricdruid.net (Tom Wiltshire)
Date: Sun, 14 Dec 2025 01:10:09 +0000
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <eea35985-c3eb-455f-a58b-ab572cb59b9e@comcast.net>
References: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
 <20251213103228.GA28738@gjcp.net>
 <CWLP265MB71325DE00E782DC7A6F97EA4DBAFA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAA79VLrsW-Le=hUMe+Enb4Ypt58W5570Lh9WXBYiFoWPDBQc-w@mail.gmail.com>
 <CAP92RBXH2udC6-eizq80EyzdB4-LFbcmMajRuhovb=qHcHE8SQ@mail.gmail.com>
 <1e46e322-0c4c-4d27-9686-a74af9695f8f@email.android.com>
 <CA+K2+DK8e=6mcGfxand9bHE+9Cg_2oRuqs_-H8XVU2a9um=ZuQ@mail.gmail.com>
 <b1e7a18e-6160-401e-8078-fa69eb6952cf@mikebeauchamp.com>
 <eea35985-c3eb-455f-a58b-ab572cb59b9e@comcast.net>
Message-ID: <AD244110-16A8-4E4C-BCC8-5AC5312F854D@electricdruid.net>

They're not "usually" pseudo-random, they *are* pseudo-random. They produce a fixed sequence the same every time. However, that sequence is statistically indistinguishable from a random signal. It certainly "sounds random". There is only any audible repetition if the LFSR is too short. The MM5837 that gave digital noise sources a bad reputation back in the day (Prophet 5, Korg Monopoly, etc) used a 17-bit register, giving a repetition rate of only a few seconds at its typical output rate of 10's of KHz. No-one complains about the 31-bit register LFSR noise in the TR-909, for example. Since the length of the sequence doubles for each extra bit you add, going a few bits beyond the 17-bit register of the MM5837 gives massive improvements. Moving up to a 24-bit register gives you an output that doesn't repeat for several minutes. By the time you're to the TR-909's 31-bit register, you're into hours, even with its much better output rate (around 250KHz).

While you _can_ screw up the implementation, LFSRs are a solid technique for good quality audio noise. There's no way you can tell the difference. There's really no need for "truly random" noise unless you're running a lottery.

Tom

> On 14 Dec 2025, at 00:48, Jay Schwichtenberg via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
> I've used the EDN noise circuit at least 3 times and it has worked just fine. I always socket the noise transistor and select it. I bought a bag of 500 2N3904 transistors (for 1 cent each) about 15 years ago.
> 
> Thing about LFSRs is they are usually pseudo random. They typically contain small sections of noise that repetitive. In most case that is good enough but not truly random. In order to get truly random noise digitally it can be somewhat complicated.
> 
> Jay S.
> 
> On 12/13/2025 1:05 PM, Mike Beauchamp wrote:
>> On 2025-12-13 09:35, Brother Theo via Synth-diy wrote:
>>> I switched to the 2 transistor noise circuit and have had zero issues since. The Future Retro 777 re-release uses that circuit.
>> 
>> Hi Timothy, doing some duckduckgo-ing, I found a few...
>> 
>> https://www.edn.com/simple-white-noise-generator/
>> 
>> https://www.nutsvolts.com/magazine/article/bipolar_transistor_cookbook_part_5 (figure 20)
>> 
>> 
>> The EDN article is interesting. Seems like the second transistor is just the amplification stage and the increased noise level is because of the addition of C1. I don't understand the function of C1.. time to get out the breadboard.
>> 
>> Mike
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org
>> View archive at: https://synth-diy.org/pipermail/synth-diy/
>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org



From loscha at gmail.com  Sun Dec 14 02:10:22 2025
From: loscha at gmail.com (Loscha)
Date: Sun, 14 Dec 2025 12:10:22 +1100
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <5bea33a9-4645-430f-b6be-3939a2b67599@comcast.net>
References: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
 <20251213103228.GA28738@gjcp.net>
 <CWLP265MB71325DE00E782DC7A6F97EA4DBAFA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAA79VLrsW-Le=hUMe+Enb4Ypt58W5570Lh9WXBYiFoWPDBQc-w@mail.gmail.com>
 <CAP92RBXH2udC6-eizq80EyzdB4-LFbcmMajRuhovb=qHcHE8SQ@mail.gmail.com>
 <1e46e322-0c4c-4d27-9686-a74af9695f8f@email.android.com>
 <CA+K2+DK8e=6mcGfxand9bHE+9Cg_2oRuqs_-H8XVU2a9um=ZuQ@mail.gmail.com>
 <b1e7a18e-6160-401e-8078-fa69eb6952cf@mikebeauchamp.com>
 <5bea33a9-4645-430f-b6be-3939a2b67599@comcast.net>
Message-ID: <CAA25cvdOnpQDun4_h5FO9dxcp1QcfJGJdAKcKSHoOOt2Z7UhhQ@mail.gmail.com>

Electric Druid has code and circuits for noise generators on 8 pin
microcontrollers, which I'm sure are adaptable into other platforms.

https://electricdruid.net/white-noise-source-mm5837-mm5437-replacement/
https://electricdruid.net/noise2-white-pink-noise-source/

On Sun, 14 Dec 2025 at 12:02, Jay Schwichtenberg via Synth-diy <
synth-diy at synth-diy.org> wrote:

> Looking at the EDN schematic again I think there is an error. Think C1
> should go from Q1's emitter and ground, not emitter and +12. I built
> mine with C1 going to ground.
>
> Jay S.
>
> On 12/13/2025 1:05 PM, Mike Beauchamp wrote:
> > On 2025-12-13 09:35, Brother Theo via Synth-diy wrote:
> >> I switched to the 2 transistor noise circuit and have had zero issues
> >> since. The Future Retro 777 re-release uses that circuit.
> >
> > Hi Timothy, doing some duckduckgo-ing, I found a few...
> >
> > https://www.edn.com/simple-white-noise-generator/
> >
> >
> https://www.nutsvolts.com/magazine/article/bipolar_transistor_cookbook_part_5
> > (figure 20)
> >
> >
> > The EDN article is interesting. Seems like the second transistor is
> > just the amplification stage and the increased noise level is because
> > of the addition of C1. I don't understand the function of C1.. time to
> > get out the breadboard.
> >
> > Mike
> > ________________________________________________________
> > This is the Synth-diy mailing list
> > Submit email to: Synth-diy at synth-diy.org
> > View archive at: https://synth-diy.org/pipermail/synth-diy/
> > Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> > Selling or trading? Use marketplace at synth-diy.org
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
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From jschwich53 at comcast.net  Sun Dec 14 02:26:13 2025
From: jschwich53 at comcast.net (Jay Schwichtenberg)
Date: Sat, 13 Dec 2025 17:26:13 -0800
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <5bea33a9-4645-430f-b6be-3939a2b67599@comcast.net>
References: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
 <20251213103228.GA28738@gjcp.net>
 <CWLP265MB71325DE00E782DC7A6F97EA4DBAFA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAA79VLrsW-Le=hUMe+Enb4Ypt58W5570Lh9WXBYiFoWPDBQc-w@mail.gmail.com>
 <CAP92RBXH2udC6-eizq80EyzdB4-LFbcmMajRuhovb=qHcHE8SQ@mail.gmail.com>
 <1e46e322-0c4c-4d27-9686-a74af9695f8f@email.android.com>
 <CA+K2+DK8e=6mcGfxand9bHE+9Cg_2oRuqs_-H8XVU2a9um=ZuQ@mail.gmail.com>
 <b1e7a18e-6160-401e-8078-fa69eb6952cf@mikebeauchamp.com>
 <5bea33a9-4645-430f-b6be-3939a2b67599@comcast.net>
Message-ID: <c5e92afc-8c3e-41c8-9a26-8fcd9cf334cf@comcast.net>

Looking for the reason I found the error (which I couldn't find) in the 
EDN circuit I found this.

Audio Synthesis Ep001: Super-Simple Noise Source
https://www.youtube.com/watch?v=GJwIduQmdhM

Jay S

On 12/13/2025 4:59 PM, Jay Schwichtenberg via Synth-diy wrote:
> Looking at the EDN schematic again I think there is an error. Think C1 
> should go from Q1's emitter and ground, not emitter and +12. I built 
> mine with C1 going to ground.
>
> Jay S.
>
> On 12/13/2025 1:05 PM, Mike Beauchamp wrote:
>> On 2025-12-13 09:35, Brother Theo via Synth-diy wrote:
>>> I switched to the 2 transistor noise circuit and have had zero 
>>> issues since. The Future Retro 777 re-release uses that circuit.
>>
>> Hi Timothy, doing some duckduckgo-ing, I found a few...
>>
>> https://www.edn.com/simple-white-noise-generator/
>>
>> https://www.nutsvolts.com/magazine/article/bipolar_transistor_cookbook_part_5 
>> (figure 20)
>>
>>
>> The EDN article is interesting. Seems like the second transistor is 
>> just the amplification stage and the increased noise level is because 
>> of the addition of C1. I don't understand the function of C1.. time 
>> to get out the breadboard.
>>
>> Mike
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org
>> View archive at: https://synth-diy.org/pipermail/synth-diy/
>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org

From list at mikebeauchamp.com  Sun Dec 14 06:14:16 2025
From: list at mikebeauchamp.com (Mike Beauchamp)
Date: Sun, 14 Dec 2025 00:14:16 -0500
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <5bea33a9-4645-430f-b6be-3939a2b67599@comcast.net>
References: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
 <20251213103228.GA28738@gjcp.net>
 <CWLP265MB71325DE00E782DC7A6F97EA4DBAFA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAA79VLrsW-Le=hUMe+Enb4Ypt58W5570Lh9WXBYiFoWPDBQc-w@mail.gmail.com>
 <CAP92RBXH2udC6-eizq80EyzdB4-LFbcmMajRuhovb=qHcHE8SQ@mail.gmail.com>
 <1e46e322-0c4c-4d27-9686-a74af9695f8f@email.android.com>
 <CA+K2+DK8e=6mcGfxand9bHE+9Cg_2oRuqs_-H8XVU2a9um=ZuQ@mail.gmail.com>
 <b1e7a18e-6160-401e-8078-fa69eb6952cf@mikebeauchamp.com>
 <5bea33a9-4645-430f-b6be-3939a2b67599@comcast.net>
Message-ID: <23e4d0c7-e27d-42c7-8b37-c48819973498@mikebeauchamp.com>

Thanks Jay S.

I tried placing this C1 capacitor on my existing circuit (similar to Ray 
Wilsons' 
https://musicfromouterspace.com/analogsynth_new/SOUNDLABMINIMARKII/images/slmsmarkii_page_4.gif 
)

C1 going to +12 was very bad, introduced some weird high-frequency spikes.

C1 going to ground was also bad, sounded like it added a low-pass filter 
to the sound of the noise and reduced the output volume a bit.

I'm not understanding the explanation for C1 on the EDN page at all: 
"The improved output level is due mainly to the inclusion of C1, which 
provides a low-impedance AC source to the noise source while not 
disturbing the DC bias of Q1"

Also here's the original article (very cool to flip through this magazine):
https://archive.org/details/silicon-chip-2005-no-01/page/92/mode/2up

Mike





On 2025-12-13 19:59, Jay Schwichtenberg via Synth-diy wrote:
> Looking at the EDN schematic again I think there is an error. Think C1 
> should go from Q1's emitter and ground, not emitter and +12. I built 
> mine with C1 going to ground.
> 
> Jay S.
> 
> On 12/13/2025 1:05 PM, Mike Beauchamp wrote:
>> On 2025-12-13 09:35, Brother Theo via Synth-diy wrote:
>>> I switched to the 2 transistor noise circuit and have had zero issues 
>>> since. The Future Retro 777 re-release uses that circuit.
>>
>> Hi Timothy, doing some duckduckgo-ing, I found a few...
>>
>> https://www.edn.com/simple-white-noise-generator/
>>
>> https://www.nutsvolts.com/magazine/article/bipolar_transistor_cookbook_part_5 (figure 20)
>>
>>
>> The EDN article is interesting. Seems like the second transistor is 
>> just the amplification stage and the increased noise level is because 
>> of the addition of C1. I don't understand the function of C1.. time to 
>> get out the breadboard.
>>
>> Mike
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org
>> View archive at: https://synth-diy.org/pipermail/synth-diy/
>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
> 

From oleavitt at proton.me  Sun Dec 14 07:56:30 2025
From: oleavitt at proton.me (Oren Leavitt)
Date: Sun, 14 Dec 2025 06:56:30 +0000
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <1e46e322-0c4c-4d27-9686-a74af9695f8f@email.android.com>
References: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
 <20251213103228.GA28738@gjcp.net>
 <CWLP265MB71325DE00E782DC7A6F97EA4DBAFA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAA79VLrsW-Le=hUMe+Enb4Ypt58W5570Lh9WXBYiFoWPDBQc-w@mail.gmail.com>
 <CAP92RBXH2udC6-eizq80EyzdB4-LFbcmMajRuhovb=qHcHE8SQ@mail.gmail.com>
 <1e46e322-0c4c-4d27-9686-a74af9695f8f@email.android.com>
Message-ID: <f594d8a3-3473-4e98-acc3-6f572fbc966a@proton.me>

I have a 70s 1N47xx (I forget what it is) 12 volt Zener diode that 
crackles and whistles.
It's my favorite in my collection of noise generators! This thing is 
raunchy and doesn't need a lot of gain.

On 12/13/25 7:54 AM, Mike Bryant wrote:
> Thinking back, in the 70s Zener diodes gave better noise than transistors
> 
> On 13 Dec 2025 12:52, Mattias Rickardsson <mr at analogue.org> wrote:
> 
> 
> Den l?r 13 dec. 2025 13:34Paul Perry via Synth-diy <synth-diy at synth- 
> diy.org <mailto:synth-diy at synth-diy.org>> skrev:
> 
>     Is it possible to simply amplify the thermal noise in a high value
>     resistor?
>     paul perry Melbourne Australia
> 
> 
> And/or the noise of a noisy op-amp in a high-gain setting?
> 
> /mr
> 




From lijon at kymatica.com  Sun Dec 14 14:31:47 2025
From: lijon at kymatica.com (Jonatan Liljedahl)
Date: Sun, 14 Dec 2025 14:31:47 +0100
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <eea35985-c3eb-455f-a58b-ab572cb59b9e@comcast.net>
References: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
 <20251213103228.GA28738@gjcp.net>
 <CWLP265MB71325DE00E782DC7A6F97EA4DBAFA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAA79VLrsW-Le=hUMe+Enb4Ypt58W5570Lh9WXBYiFoWPDBQc-w@mail.gmail.com>
 <CAP92RBXH2udC6-eizq80EyzdB4-LFbcmMajRuhovb=qHcHE8SQ@mail.gmail.com>
 <1e46e322-0c4c-4d27-9686-a74af9695f8f@email.android.com>
 <CA+K2+DK8e=6mcGfxand9bHE+9Cg_2oRuqs_-H8XVU2a9um=ZuQ@mail.gmail.com>
 <b1e7a18e-6160-401e-8078-fa69eb6952cf@mikebeauchamp.com>
 <eea35985-c3eb-455f-a58b-ab572cb59b9e@comcast.net>
Message-ID: <CALfiFhACwFx3OpTkfg7qgA2sp2N+XCyzQqGZ4W12VOBYHTPaCg@mail.gmail.com>

A 32-bit maximum length LFSR gives a sequence of 2**32-1, which at a sample
rate of 44.1kHz repeats after 27 hours! :)

/Jonatan
http://kymatica.com


s?n 14 dec. 2025 kl. 01:53 skrev Jay Schwichtenberg via Synth-diy <
synth-diy at synth-diy.org>:

> I've used the EDN noise circuit at least 3 times and it has worked just
> fine. I always socket the noise transistor and select it. I bought a bag
> of 500 2N3904 transistors (for 1 cent each) about 15 years ago.
>
> Thing about LFSRs is they are usually pseudo random. They typically
> contain small sections of noise that repetitive. In most case that is
> good enough but not truly random. In order to get truly random noise
> digitally it can be somewhat complicated.
>
> Jay S.
>
> On 12/13/2025 1:05 PM, Mike Beauchamp wrote:
> > On 2025-12-13 09:35, Brother Theo via Synth-diy wrote:
> >> I switched to the 2 transistor noise circuit and have had zero issues
> >> since. The Future Retro 777 re-release uses that circuit.
> >
> > Hi Timothy, doing some duckduckgo-ing, I found a few...
> >
> > https://www.edn.com/simple-white-noise-generator/
> >
> >
> https://www.nutsvolts.com/magazine/article/bipolar_transistor_cookbook_part_5
> > (figure 20)
> >
> >
> > The EDN article is interesting. Seems like the second transistor is
> > just the amplification stage and the increased noise level is because
> > of the addition of C1. I don't understand the function of C1.. time to
> > get out the breadboard.
> >
> > Mike
> > ________________________________________________________
> > This is the Synth-diy mailing list
> > Submit email to: Synth-diy at synth-diy.org
> > View archive at: https://synth-diy.org/pipermail/synth-diy/
> > Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> > Selling or trading? Use marketplace at synth-diy.org
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
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From mort_win at yahoo.co.uk  Sun Dec 14 14:58:18 2025
From: mort_win at yahoo.co.uk (david walker)
Date: Sun, 14 Dec 2025 13:58:18 +0000 (UTC)
Subject: [sdiy] traffic lights
References: <731904305.956870.1765720698039.ref@mail.yahoo.com>
Message-ID: <731904305.956870.1765720698039@mail.yahoo.com>

Hello hope sum one can help but i got sum?Grain of Wheat Bulbs 12V red yellow and green so you can see were i am going with them what i would like to does any have any simple designs like using a 555 or sum other essay to use compotes so make a set of traffic lights so any help would be a big thanks??
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From grant at musictechnologiesgroup.com  Sun Dec 14 17:31:41 2025
From: grant at musictechnologiesgroup.com (grant musictechnologiesgroup.com)
Date: Sun, 14 Dec 2025 16:31:41 +0000
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <b1e7a18e-6160-401e-8078-fa69eb6952cf@mikebeauchamp.com>
References: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
 <20251213103228.GA28738@gjcp.net>
 <CWLP265MB71325DE00E782DC7A6F97EA4DBAFA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAA79VLrsW-Le=hUMe+Enb4Ypt58W5570Lh9WXBYiFoWPDBQc-w@mail.gmail.com>
 <CAP92RBXH2udC6-eizq80EyzdB4-LFbcmMajRuhovb=qHcHE8SQ@mail.gmail.com>
 <1e46e322-0c4c-4d27-9686-a74af9695f8f@email.android.com>
 <CA+K2+DK8e=6mcGfxand9bHE+9Cg_2oRuqs_-H8XVU2a9um=ZuQ@mail.gmail.com>
 <b1e7a18e-6160-401e-8078-fa69eb6952cf@mikebeauchamp.com>
Message-ID: <3a8a6cb2-a72b-4712-8d11-72a8be7d66b5@musictechnologiesgroup.com>

Can anyone see the 10 comments below the article? They are not showing 
up for me and those professional magazine usually have great comments.

GB

On 12/13/2025 1:05 PM, Mike Beauchamp wrote:
> On 2025-12-13 09:35, Brother Theo via Synth-diy wrote:
>> I switched to the 2 transistor noise circuit and have had zero issues 
>> since. The Future Retro 777 re-release uses that circuit.
>
> Hi Timothy, doing some duckduckgo-ing, I found a few...
>
> https://www.edn.com/simple-white-noise-generator/
>
> https://www.nutsvolts.com/magazine/article/bipolar_transistor_cookbook_part_5 
> (figure 20)
>
>
> The EDN article is interesting. Seems like the second transistor is 
> just the amplification stage and the increased noise level is because 
> of the addition of C1. I don't understand the function of C1.. time to 
> get out the breadboard.
>
> Mike
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org



From fluxmonk at gmail.com  Sun Dec 14 18:03:47 2025
From: fluxmonk at gmail.com (bbob)
Date: Sun, 14 Dec 2025 12:03:47 -0500
Subject: [sdiy] traffic lights
In-Reply-To: <731904305.956870.1765720698039@mail.yahoo.com>
References: <731904305.956870.1765720698039.ref@mail.yahoo.com>
 <731904305.956870.1765720698039@mail.yahoo.com>
Message-ID: <CABbX2d8-39_6TGYAxj3YUQoGqJOR2BWdsnwNmkMOnmhumrwLzg@mail.gmail.com>

i don't always say this, but a small arduino-compatible microcontroller
would probably be an easier/smaller/cheaper solution for this.

On Sun, Dec 14, 2025 at 9:00?AM david walker via Synth-diy <
synth-diy at synth-diy.org> wrote:

> Hello hope sum one can help but i got sum Grain of Wheat Bulbs 12V red
> yellow and green so you can see were i am going with them what i would like
> to does any have any simple designs like using a 555 or sum other essay to
> use compotes so make a set of traffic lights so any help would be a big
> thanks [image: Emoji]
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
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From jpdesroc at oricom.ca  Sun Dec 14 18:17:36 2025
From: jpdesroc at oricom.ca (jpdesroc at oricom.ca)
Date: Sun, 14 Dec 2025 12:17:36 -0500
Subject: [sdiy] traffic lights
In-Reply-To: <731904305.956870.1765720698039@mail.yahoo.com>
References: <731904305.956870.1765720698039.ref@mail.yahoo.com>
 <731904305.956870.1765720698039@mail.yahoo.com>
Message-ID: <000001dc6d1d$8ba137b0$a2e3a710$@oricom.ca>

I think you?ll get in trouble using a single 555 to do what you need.

But using 2 CMOS IC?s like the CD4049 and a CD4017 you?ll do what you need.

Making a slow oscillator with one of the 4049 inverter (or a small transistor wired to oscillate),

Then wiring a 4017 so it will reset after 3 consecutive outputs

(wiring output ?4? pin 7 to reset pin 15).

Make sure pin 13 is wired to the GND.

The first 3 outputs (pins 3,2,4) will do the GREEN,YELLOW,RED.

But since the CD4017 cannot sink or supply enough current
to lite 12v bulbs just use 3 transistors to drive them from the 4017 outs.

But a small PIC would easily do that job with 3 transistors..

 

 

De : Synth-diy <synth-diy-bounces at synth-diy.org> De la part de david walker via Synth-diy
Envoy? : 14 d?cembre 2025 08:58
? : synth-diy at synth-diy.org
Objet : [sdiy] traffic lights

 

Hello hope sum one can help but i got sum Grain of Wheat Bulbs 12V red yellow and green so you can see were i am going with them what i would like to does any have any simple designs like using a 555 or sum other essay to use compotes so make a set of traffic lights so any help would be a big thanks   <https://s.yimg.com/nq/yemoji_assets/latest/yemoji_assets/1f642.png>  

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From grant at musictechnologiesgroup.com  Sun Dec 14 18:36:00 2025
From: grant at musictechnologiesgroup.com (grant musictechnologiesgroup.com)
Date: Sun, 14 Dec 2025 17:36:00 +0000
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <3a8a6cb2-a72b-4712-8d11-72a8be7d66b5@musictechnologiesgroup.com>
References: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
 <20251213103228.GA28738@gjcp.net>
 <CWLP265MB71325DE00E782DC7A6F97EA4DBAFA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAA79VLrsW-Le=hUMe+Enb4Ypt58W5570Lh9WXBYiFoWPDBQc-w@mail.gmail.com>
 <CAP92RBXH2udC6-eizq80EyzdB4-LFbcmMajRuhovb=qHcHE8SQ@mail.gmail.com>
 <1e46e322-0c4c-4d27-9686-a74af9695f8f@email.android.com>
 <CA+K2+DK8e=6mcGfxand9bHE+9Cg_2oRuqs_-H8XVU2a9um=ZuQ@mail.gmail.com>
 <b1e7a18e-6160-401e-8078-fa69eb6952cf@mikebeauchamp.com>
 <3a8a6cb2-a72b-4712-8d11-72a8be7d66b5@musictechnologiesgroup.com>
Message-ID: <b5eb4455-6390-4932-b036-2dabca7f4bc6@musictechnologiesgroup.com>

Curiously this one shows all the comments:

https://www.edn.com/a-non-finicky-mass-producible-audio-frequency-white-noise-generator/

On 12/14/2025 8:31 AM, grant musictechnologiesgroup.com wrote:
> Can anyone see the 10 comments below the EDN article? They are not showing
> up for me and those professional magazines usually have great comments.
>
> GB
>
> On 12/13/2025 1:05 PM, Mike Beauchamp wrote:
>> On 2025-12-13 09:35, Brother Theo via Synth-diy wrote:
>>> I switched to the 2 transistor noise circuit and have had zero issues
>>> since. The Future Retro 777 re-release uses that circuit.
>> Hi Timothy, doing some duckduckgo-ing, I found a few...
>>
>> https://www.edn.com/simple-white-noise-generator/
>>
>> https://www.nutsvolts.com/magazine/article/bipolar_transistor_cookbook_part_5
>> (figure 20)
>>
>>
>> The EDN article is interesting. Seems like the second transistor is
>> just the amplification stage and the increased noise level is because
>> of the addition of C1. I don't understand the function of C1.. time to
>> get out the breadboard.
>>
>> Mike
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org
>> View archive at: https://synth-diy.org/pipermail/synth-diy/
>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org



From grenert at gmail.com  Sun Dec 14 19:00:22 2025
From: grenert at gmail.com (grenert)
Date: Sun, 14 Dec 2025 10:00:22 -0800
Subject: [sdiy] traffic lights
In-Reply-To: <731904305.956870.1765720698039@mail.yahoo.com>
References: <731904305.956870.1765720698039.ref@mail.yahoo.com>
 <731904305.956870.1765720698039@mail.yahoo.com>
Message-ID: <CAGkoGzg=cAN3kB9s5tYnZ_o0VPCCv0MUFG_wf++8qkhdWpNkLw@mail.gmail.com>

This is model railroad stuff, should work:
https://www.aliexpress.us/item/3256808338510072.html?gatewayAdapt=glo2usa4itemAdapt


On Sun, Dec 14, 2025 at 6:00?AM david walker via Synth-diy <
synth-diy at synth-diy.org> wrote:

> Hello hope sum one can help but i got sum Grain of Wheat Bulbs 12V red
> yellow and green so you can see were i am going with them what i would like
> to does any have any simple designs like using a 555 or sum other essay to
> use compotes so make a set of traffic lights so any help would be a big
> thanks [image: Emoji]
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
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From oleavitt at proton.me  Sun Dec 14 20:26:40 2025
From: oleavitt at proton.me (Oren Leavitt)
Date: Sun, 14 Dec 2025 19:26:40 +0000
Subject: [sdiy] traffic lights
In-Reply-To: <731904305.956870.1765720698039@mail.yahoo.com>
References: <731904305.956870.1765720698039.ref@mail.yahoo.com>
 <731904305.956870.1765720698039@mail.yahoo.com>
Message-ID: <11485b33-d256-4e0b-bb09-17507f318c74@proton.me>

Back in the 1970s I built a traffic light from a magazine article that 
used a few 40xx series CMOS ICs and some transistors to drive the lamps.
If I find the article, I'll post it.
Nowadays, you can do this easily with a PIC, Arduino, or whatever 
microcontroller and some transistors to drive the 12V lamps.

On 12/14/25 7:58 AM, david walker via Synth-diy wrote:
> Hello hope sum one can help but i got sum Grain of Wheat Bulbs 12V red 
> yellow and green so you can see were i am going with them what i would 
> like to does any have any simple designs like using a 555 or sum other 
> essay to use compotes so make a set of traffic lights so any help would 
> be a big thanks Emoji




From gordonjcp at gjcp.net  Sun Dec 14 20:57:35 2025
From: gordonjcp at gjcp.net (Gordonjcp)
Date: Sun, 14 Dec 2025 19:57:35 +0000
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <AD244110-16A8-4E4C-BCC8-5AC5312F854D@electricdruid.net>
References: <b3048277-9853-48e8-b649-19e1e296f5c2@mikebeauchamp.com>
 <20251213103228.GA28738@gjcp.net>
 <CWLP265MB71325DE00E782DC7A6F97EA4DBAFA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <CAA79VLrsW-Le=hUMe+Enb4Ypt58W5570Lh9WXBYiFoWPDBQc-w@mail.gmail.com>
 <CAP92RBXH2udC6-eizq80EyzdB4-LFbcmMajRuhovb=qHcHE8SQ@mail.gmail.com>
 <1e46e322-0c4c-4d27-9686-a74af9695f8f@email.android.com>
 <CA+K2+DK8e=6mcGfxand9bHE+9Cg_2oRuqs_-H8XVU2a9um=ZuQ@mail.gmail.com>
 <b1e7a18e-6160-401e-8078-fa69eb6952cf@mikebeauchamp.com>
 <eea35985-c3eb-455f-a58b-ab572cb59b9e@comcast.net>
 <AD244110-16A8-4E4C-BCC8-5AC5312F854D@electricdruid.net>
Message-ID: <20251214195735.GA1515@gjcp.net>

On Sun, Dec 14, 2025 at 01:10:09AM +0000, Tom Wiltshire wrote:
> 
> While you _can_ screw up the implementation, LFSRs are a solid technique for good quality audio noise. There's no way you can tell the difference. There's really no need for "truly random" noise unless you're running a lottery.

Another neat property of LFSRs is that with correctly-chosen taps they will output a permutation of all their possible values except 0 (there must always be at least one bit set). This is for example how the Wolfenstein 3D "fizzle fade" effect is achieved. I feel like there's some sort of very clever arpeggiator in that, somewhere.

-- 
Gordonjcp


From ben at stuyts.nl  Sun Dec 14 21:21:26 2025
From: ben at stuyts.nl (Ben Stuyts)
Date: Sun, 14 Dec 2025 21:21:26 +0100
Subject: [sdiy] traffic lights
In-Reply-To: <731904305.956870.1765720698039@mail.yahoo.com>
References: <731904305.956870.1765720698039.ref@mail.yahoo.com>
 <731904305.956870.1765720698039@mail.yahoo.com>
Message-ID: <E45D7811-411B-40C8-8873-648AF1EEC142@stuyts.nl>

If you just want it to loop around, have look at ring multivibrators. These extend the basic 2-transistor multivibrator for more stages. E.g. this schematic from https://electronics.stackexchange.com/questions/678865/is-there-any-such-thing-as-a-tristable-quadristable-etc-multivibrator

?

Replace R2, R3, R4 with your light bulbs (and series resistor is needed) and adjust the capacitors to suit the required frequency.

Ben


> On 14 Dec 2025, at 14:58, david walker via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
> Hello hope sum one can help but i got sum Grain of Wheat Bulbs 12V red yellow and green so you can see were i am going with them what i would like to does any have any simple designs like using a 555 or sum other essay to use compotes so make a set of traffic lights so any help would be a big thanks  
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org

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From mbryant at futurehorizons.com  Sun Dec 14 21:38:54 2025
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Sun, 14 Dec 2025 20:38:54 +0000
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <509C773B-6FB9-4303-9780-F62012F813CE@comcast.net>
References: <20251213192248.GA30200@gjcp.net>
 <509C773B-6FB9-4303-9780-F62012F813CE@comcast.net>
Message-ID: <CWLP265MB7132BB62D7C982EE6D01F746DBACA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>

I think you'll find the LM194 and its clones are the only monolithic ones left now.   There were others a few years ago but most others are now two very well matched but separate die in the same package.
________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Ian Fritz via Synth-diy <synth-diy at synth-diy.org>
Sent: 13 December 2025 19:53
To: Gordonjcp <gordonjcp at gjcp.net>
Cc: synth-diy at synth-diy.org <synth-diy at synth-diy.org>
Subject: Re: [sdiy] SMT transistor for white noise?

Do they have these in monolithic pair packages?

Ian

> On Dec 13, 2025, at 12:27?PM, Gordonjcp <gordonjcp at gjcp.net> wrote:
>
> ?On Sat, Dec 13, 2025 at 11:11:54AM +0000, Mike Bryant wrote:
>> Too true ?   A large percentage of the world's small signal transistors now come from a huge fab in Chongqing and they just brand them to whatever their client wants.
>>
>
> Many years ago I bought a bag of something like 500 of the cheapest Chinesiest BC548-wannabes from Some Dude In Shenzen On eBay, expecting to maybe hand-match a couple of sets of a dozen reasonably close ones for filters.
>
> Nope.
>
> Any two you pulled out of the bag at random would have the same Vbe down to *microvolts*.
>
> So that was a quicker evening than I anticipated.
>
> --
> Gordonjcp
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org


________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org
View archive at: https://synth-diy.org/pipermail/synth-diy/
Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
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From hugh at blemings.org  Sun Dec 14 23:28:21 2025
From: hugh at blemings.org (Hugh Blemings)
Date: Mon, 15 Dec 2025 09:28:21 +1100
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <CWLP265MB7132BB62D7C982EE6D01F746DBACA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
References: <20251213192248.GA30200@gjcp.net>
 <509C773B-6FB9-4303-9780-F62012F813CE@comcast.net>
 <CWLP265MB7132BB62D7C982EE6D01F746DBACA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <89884d8e-93da-4253-8d19-06f3ed3f39e3@blemings.org>

Hi All,


I'm reminded of "ChaosKey" a design that Keith Packard and Bdale Garbee 
put together to create entropy for the random number generator in the 
Linux kernel.? It's based off a pair of transistors biased up at 
something like 20V and fully open source. https://altusmetrum.org/ChaosKey/


Might be of interest?

Cheers,
Hugh



On 15/12/2025 07:38, Mike Bryant wrote:
> I think you'll find the LM194 and its clones are the only monolithic 
> ones left now.? ?There were others a few years ago but most others are 
> now two very well matched but separate die in the same package.
> ------------------------------------------------------------------------
> *From:* Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Ian 
> Fritz via Synth-diy <synth-diy at synth-diy.org>
> *Sent:* 13 December 2025 19:53
> *To:* Gordonjcp <gordonjcp at gjcp.net>
> *Cc:* synth-diy at synth-diy.org <synth-diy at synth-diy.org>
> *Subject:* Re: [sdiy] SMT transistor for white noise?
> Do they have these in monolithic pair packages?
>
> Ian
>
> > On Dec 13, 2025, at 12:27?PM, Gordonjcp <gordonjcp at gjcp.net> wrote:
> >
> > ?On Sat, Dec 13, 2025 at 11:11:54AM +0000, Mike Bryant wrote:
> >> Too true ??? A large percentage of the world's small signal 
> transistors now come from a huge fab in Chongqing and they just brand 
> them to whatever their client wants.
> >>
> >
> > Many years ago I bought a bag of something like 500 of the cheapest 
> Chinesiest BC548-wannabes from Some Dude In Shenzen On eBay, expecting 
> to maybe hand-match a couple of sets of a dozen reasonably close ones 
> for filters.
> >
> > Nope.
> >
> > Any two you pulled out of the bag at random would have the same Vbe 
> down to *microvolts*.
> >
> > So that was a quicker evening than I anticipated.
> >
> > --
> > Gordonjcp
> >
> > ________________________________________________________
> > This is the Synth-diy mailing list
> > Submit email to: Synth-diy at synth-diy.org
> > View archive at: https://synth-diy.org/pipermail/synth-diy/
> > Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> > Selling or trading? Use marketplace at synth-diy.org
>
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to:Synth-diy at synth-diy.org
> View archive at:https://synth-diy.org/pipermail/synth-diy/
> Check your settings at:https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Usemarketplace at synth-diy.org

-- 
I am slowly moving tohugh at blemings.id.au as my main email address.
If you're usinghugh at blemings.org please update your address book accordingly.
Thank you :)
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From markverbos at gmail.com  Mon Dec 15 11:23:53 2025
From: markverbos at gmail.com (mark verbos)
Date: Mon, 15 Dec 2025 11:23:53 +0100
Subject: [sdiy] SMT transistor for white noise?
In-Reply-To: <89884d8e-93da-4253-8d19-06f3ed3f39e3@blemings.org>
References: <20251213192248.GA30200@gjcp.net>
 <509C773B-6FB9-4303-9780-F62012F813CE@comcast.net>
 <CWLP265MB7132BB62D7C982EE6D01F746DBACA@CWLP265MB7132.GBRP265.PROD.OUTLOOK.COM>
 <89884d8e-93da-4253-8d19-06f3ed3f39e3@blemings.org>
Message-ID: <EBB2E3DE-3453-45DA-9FE7-2789B3917F4B@gmail.com>


https://www.lavarand.org/?
LavaRnd
lavarand.org





> On Dec 14, 2025, at 23:28, Hugh Blemings <hugh at blemings.org> wrote:
> 
> Hi All,
> 
> I'm reminded of "ChaosKey" a design that Keith Packard and Bdale Garbee put together to create entropy for the random number generator in the Linux kernel.  It's based off a pair of transistors biased up at something like 20V and fully open source.  https://altusmetrum.org/ChaosKey/
> 
> Might be of interest?
> 
> Cheers,
> Hugh
> 
> 
> On 15/12/2025 07:38, Mike Bryant wrote:
>> I think you'll find the LM194 and its clones are the only monolithic ones left now.   There were others a few years ago but most others are now two very well matched but separate die in the same package.
>> From: Synth-diy <synth-diy-bounces at synth-diy.org> <mailto:synth-diy-bounces at synth-diy.org> on behalf of Ian Fritz via Synth-diy <synth-diy at synth-diy.org> <mailto:synth-diy at synth-diy.org>
>> Sent: 13 December 2025 19:53
>> To: Gordonjcp <gordonjcp at gjcp.net> <mailto:gordonjcp at gjcp.net>
>> Cc: synth-diy at synth-diy.org <mailto:synth-diy at synth-diy.org> <synth-diy at synth-diy.org> <mailto:synth-diy at synth-diy.org>
>> Subject: Re: [sdiy] SMT transistor for white noise?
>>  
>> Do they have these in monolithic pair packages?
>> 
>> Ian
>> 
>> > On Dec 13, 2025, at 12:27?PM, Gordonjcp <gordonjcp at gjcp.net> <mailto:gordonjcp at gjcp.net> wrote:
>> > 
>> > ?On Sat, Dec 13, 2025 at 11:11:54AM +0000, Mike Bryant wrote:
>> >> Too true ?   A large percentage of the world's small signal transistors now come from a huge fab in Chongqing and they just brand them to whatever their client wants.
>> >> 
>> > 
>> > Many years ago I bought a bag of something like 500 of the cheapest Chinesiest BC548-wannabes from Some Dude In Shenzen On eBay, expecting to maybe hand-match a couple of sets of a dozen reasonably close ones for filters.
>> > 
>> > Nope.
>> > 
>> > Any two you pulled out of the bag at random would have the same Vbe down to *microvolts*.
>> > 
>> > So that was a quicker evening than I anticipated.
>> > 
>> > --
>> > Gordonjcp
>> > 
>> > ________________________________________________________
>> > This is the Synth-diy mailing list
>> > Submit email to: Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
>> > View archive at: https://synth-diy.org/pipermail/synth-diy/
>> > Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>> > Selling or trading? Use marketplace at synth-diy.org <mailto:marketplace at synth-diy.org>
>> 
>> 
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
>> View archive at: https://synth-diy.org/pipermail/synth-diy/
>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org <mailto:marketplace at synth-diy.org>
>> 
>> 
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
>> View archive at: https://synth-diy.org/pipermail/synth-diy/
>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org <mailto:marketplace at synth-diy.org>
> -- 
> I am slowly moving to hugh at blemings.id.au <mailto:hugh at blemings.id.au> as my main email address.
> If you're using hugh at blemings.org <mailto:hugh at blemings.org> please update your address book accordingly.
> Thank you :)
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org <mailto:marketplace at synth-diy.org>
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From jpdesroc at oricom.ca  Tue Dec 23 16:53:44 2025
From: jpdesroc at oricom.ca (jpdesroc at oricom.ca)
Date: Tue, 23 Dec 2025 10:53:44 -0500
Subject: [sdiy] Software that intercepts MIDI notes and readjust velocity
 values to a fixed value.. ?
In-Reply-To: <44a9d773-6a4b-458f-9f3a-ed806b6874d8@go2.pl>
References: <002d01dba412$077a6530$166f2f90$@oricom.ca>
 <44a9d773-6a4b-458f-9f3a-ed806b6874d8@go2.pl>
Message-ID: <000001dc7424$51ea0c50$f5be24f0$@oricom.ca>

I'm using a small M-AUDIO Keystation61 MK3 MIDI keyboard
to record notes in my Sonar X3 DAW.
I'm connected through USB cable and it works fine.
Since I'm not a keyboard player I'm not used to velocity playing  'awareness'
so I get many different velocity recorded while I play this keyboard.
This can be annoying when I play organ or some synth plugins.
So.. I'd like to 'fix' all the MIDI notes to full velocity when I desire it
but I could,nt find a way to do it.
Sonar as no MIDI settings for velocity that I could fix to 127 (max)
So I need a third party utility that would 'intercepts' and correct the incoming MIDI notes
And readjust the velocities before reaching to my DAW.
My keyboard has both USB and DIN 5pins MIDI out connectors.
I could build a small box with MIDI IN/OUT that would do the velocity correction
but to me it's like re-inventing the wheel.
I do prefer to stick with my USB cable only but will not go to USB programing requirements
for an external box I would build.
I found this but I'm not sure if it's what I need: https://plugins4free.com/plugin/2154/

So.. any suggestions for a small application that would do that ?





From dave at expeditionelectronics.com  Tue Dec 23 17:01:09 2025
From: dave at expeditionelectronics.com (David Moylan)
Date: Tue, 23 Dec 2025 11:01:09 -0500
Subject: [sdiy] Software that intercepts MIDI notes and readjust
 velocity values to a fixed value.. ?
In-Reply-To: <000001dc7424$51ea0c50$f5be24f0$@oricom.ca>
References: <002d01dba412$077a6530$166f2f90$@oricom.ca>
 <44a9d773-6a4b-458f-9f3a-ed806b6874d8@go2.pl>
 <000001dc7424$51ea0c50$f5be24f0$@oricom.ca>
Message-ID: <c25b3b5a-0795-4c01-8cb4-cc97210feafa@expeditionelectronics.com>

Hmm, don't the synth plugins have options to ignore velocity?

On 12/23/25 10:53 AM, Jean-Pierre Desrochers via Synth-diy wrote:
> I'm using a small M-AUDIO Keystation61 MK3 MIDI keyboard
> to record notes in my Sonar X3 DAW.
> I'm connected through USB cable and it works fine.
> Since I'm not a keyboard player I'm not used to velocity playing  'awareness'
> so I get many different velocity recorded while I play this keyboard.
> This can be annoying when I play organ or some synth plugins.
> So.. I'd like to 'fix' all the MIDI notes to full velocity when I desire it
> but I could,nt find a way to do it.
> Sonar as no MIDI settings for velocity that I could fix to 127 (max)
> So I need a third party utility that would 'intercepts' and correct the incoming MIDI notes
> And readjust the velocities before reaching to my DAW.
> My keyboard has both USB and DIN 5pins MIDI out connectors.
> I could build a small box with MIDI IN/OUT that would do the velocity correction
> but to me it's like re-inventing the wheel.
> I do prefer to stick with my USB cable only but will not go to USB programing requirements
> for an external box I would build.
> I found this but I'm not sure if it's what I need: https://plugins4free.com/plugin/2154/
>
> So.. any suggestions for a small application that would do that ?
>
>
>
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org


-- 
David Moylan
Expedition Electronics
sonic adventures!


From jpdesroc at oricom.ca  Tue Dec 23 17:03:35 2025
From: jpdesroc at oricom.ca (jpdesroc at oricom.ca)
Date: Tue, 23 Dec 2025 11:03:35 -0500
Subject: [sdiy] Software that intercepts MIDI notes and readjust
 velocity values to a fixed value.. ?
In-Reply-To: <c25b3b5a-0795-4c01-8cb4-cc97210feafa@expeditionelectronics.com>
References: <002d01dba412$077a6530$166f2f90$@oricom.ca>
 <44a9d773-6a4b-458f-9f3a-ed806b6874d8@go2.pl>
 <000001dc7424$51ea0c50$f5be24f0$@oricom.ca>
 <c25b3b5a-0795-4c01-8cb4-cc97210feafa@expeditionelectronics.com>
Message-ID: <000101dc7425$b26074b0$17215e10$@oricom.ca>

I mostly use Arturia 2025.4 V Collection plugins and I did not find any
settings that would do that..

-----Message d'origine-----
De?: Synth-diy <synth-diy-bounces at synth-diy.org> De la part de David Moylan
via Synth-diy
Envoy??: 23 d?cembre 2025 11:01
??: synth-diy at synth-diy.org
Objet?: Re: [sdiy] Software that intercepts MIDI notes and readjust velocity
values to a fixed value.. ?

Hmm, don't the synth plugins have options to ignore velocity?

On 12/23/25 10:53 AM, Jean-Pierre Desrochers via Synth-diy wrote:
> I'm using a small M-AUDIO Keystation61 MK3 MIDI keyboard to record 
> notes in my Sonar X3 DAW.
> I'm connected through USB cable and it works fine.
> Since I'm not a keyboard player I'm not used to velocity playing
'awareness'
> so I get many different velocity recorded while I play this keyboard.
> This can be annoying when I play organ or some synth plugins.
> So.. I'd like to 'fix' all the MIDI notes to full velocity when I 
> desire it but I could,nt find a way to do it.
> Sonar as no MIDI settings for velocity that I could fix to 127 (max) 
> So I need a third party utility that would 'intercepts' and correct 
> the incoming MIDI notes And readjust the velocities before reaching to my
DAW.
> My keyboard has both USB and DIN 5pins MIDI out connectors.
> I could build a small box with MIDI IN/OUT that would do the velocity 
> correction but to me it's like re-inventing the wheel.
> I do prefer to stick with my USB cable only but will not go to USB 
> programing requirements for an external box I would build.
> I found this but I'm not sure if it's what I need: 
> https://plugins4free.com/plugin/2154/
>
> So.. any suggestions for a small application that would do that ?
>
>
>
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org View archive at: 
> https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: 
> https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org


--
David Moylan
Expedition Electronics
sonic adventures!

________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org View archive at:
https://synth-diy.org/pipermail/synth-diy/
Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
Selling or trading? Use marketplace at synth-diy.org



From fanwander at mnet-online.de  Tue Dec 23 17:23:36 2025
From: fanwander at mnet-online.de (Florian Anwander)
Date: Tue, 23 Dec 2025 17:23:36 +0100
Subject: [sdiy] Software that intercepts MIDI notes and readjust
 velocity values to a fixed value.. ?
In-Reply-To: <000001dc7424$51ea0c50$f5be24f0$@oricom.ca>
References: <002d01dba412$077a6530$166f2f90$@oricom.ca>
 <44a9d773-6a4b-458f-9f3a-ed806b6874d8@go2.pl>
 <000001dc7424$51ea0c50$f5be24f0$@oricom.ca>
Message-ID: <56328443-1eb5-4286-96b6-1f969d2f3c59@mnet-online.de>

Hello Jean-Pierre

Am 23.12.25 um 16:53 schrieb Jean-Pierre Desrochers via Synth-diy:
> I found this but I'm not sure if it's what I need:https://plugins4free.com/plugin/2154/

This will change the velocity sent by the track while playing back. It 
will not set the recorded velocity.

Florian


From shawnrakestraw at gmail.com  Tue Dec 23 17:24:47 2025
From: shawnrakestraw at gmail.com (Shawn Rakestraw)
Date: Tue, 23 Dec 2025 11:24:47 -0500
Subject: [sdiy] Software that intercepts MIDI notes and readjust
 velocity values to a fixed value.. ?
In-Reply-To: <000101dc7425$b26074b0$17215e10$@oricom.ca>
References: <002d01dba412$077a6530$166f2f90$@oricom.ca>
 <44a9d773-6a4b-458f-9f3a-ed806b6874d8@go2.pl>
 <000001dc7424$51ea0c50$f5be24f0$@oricom.ca>
 <c25b3b5a-0795-4c01-8cb4-cc97210feafa@expeditionelectronics.com>
 <000101dc7425$b26074b0$17215e10$@oricom.ca>
Message-ID: <CA+-UNiCi4ZN-w-DEYRYk+QBN0J0eYW8kPGE42OjceiVHum0b2g@mail.gmail.com>

If I were you, I would look for a solution within your DAW rather than in
hardware form. I am not familiar with Sonar at all, so I can't be specific,
but in other DAWs, there are usually plugins that allow all sorts of MIDI
note manipulation. You usually just place the MIDI plugin immediately
before your synth plugin. You could even place a few in a row, like a
plugin that creates chords from single notes and then another that makes
arpeggios from those chords.

On Tue, Dec 23, 2025 at 11:06?AM Jean-Pierre Desrochers via Synth-diy <
synth-diy at synth-diy.org> wrote:

> I mostly use Arturia 2025.4 V Collection plugins and I did not find any
> settings that would do that..
>
> -----Message d'origine-----
> De : Synth-diy <synth-diy-bounces at synth-diy.org> De la part de David
> Moylan
> via Synth-diy
> Envoy? : 23 d?cembre 2025 11:01
> ? : synth-diy at synth-diy.org
> Objet : Re: [sdiy] Software that intercepts MIDI notes and readjust
> velocity
> values to a fixed value.. ?
>
> Hmm, don't the synth plugins have options to ignore velocity?
>
> On 12/23/25 10:53 AM, Jean-Pierre Desrochers via Synth-diy wrote:
> > I'm using a small M-AUDIO Keystation61 MK3 MIDI keyboard to record
> > notes in my Sonar X3 DAW.
> > I'm connected through USB cable and it works fine.
> > Since I'm not a keyboard player I'm not used to velocity playing
> 'awareness'
> > so I get many different velocity recorded while I play this keyboard.
> > This can be annoying when I play organ or some synth plugins.
> > So.. I'd like to 'fix' all the MIDI notes to full velocity when I
> > desire it but I could,nt find a way to do it.
> > Sonar as no MIDI settings for velocity that I could fix to 127 (max)
> > So I need a third party utility that would 'intercepts' and correct
> > the incoming MIDI notes And readjust the velocities before reaching to my
> DAW.
> > My keyboard has both USB and DIN 5pins MIDI out connectors.
> > I could build a small box with MIDI IN/OUT that would do the velocity
> > correction but to me it's like re-inventing the wheel.
> > I do prefer to stick with my USB cable only but will not go to USB
> > programing requirements for an external box I would build.
> > I found this but I'm not sure if it's what I need:
> > https://plugins4free.com/plugin/2154/
> >
> > So.. any suggestions for a small application that would do that ?
> >
> >
> >
> >
> > ________________________________________________________
> > This is the Synth-diy mailing list
> > Submit email to: Synth-diy at synth-diy.org View archive at:
> > https://synth-diy.org/pipermail/synth-diy/
> > Check your settings at:
> > https://synth-diy.org/mailman/listinfo/synth-diy
> > Selling or trading? Use marketplace at synth-diy.org
>
>
> --
> David Moylan
> Expedition Electronics
> sonic adventures!
>
> ________________________________________________________
> This is the Synth-diy mailing list
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> https://synth-diy.org/pipermail/synth-diy/
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>
> ________________________________________________________
> This is the Synth-diy mailing list
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From philgallo at gmail.com  Tue Dec 23 18:40:11 2025
From: philgallo at gmail.com (Phillip Gallo)
Date: Tue, 23 Dec 2025 10:40:11 -0700
Subject: [sdiy] Software that intercepts MIDI notes and readjust
 velocity values to a fixed value.. ?
In-Reply-To: <CA+-UNiCi4ZN-w-DEYRYk+QBN0J0eYW8kPGE42OjceiVHum0b2g@mail.gmail.com>
References: <002d01dba412$077a6530$166f2f90$@oricom.ca>
 <44a9d773-6a4b-458f-9f3a-ed806b6874d8@go2.pl>
 <000001dc7424$51ea0c50$f5be24f0$@oricom.ca>
 <c25b3b5a-0795-4c01-8cb4-cc97210feafa@expeditionelectronics.com>
 <000101dc7425$b26074b0$17215e10$@oricom.ca>
 <CA+-UNiCi4ZN-w-DEYRYk+QBN0J0eYW8kPGE42OjceiVHum0b2g@mail.gmail.com>
Message-ID: <CAN4YM6dzVkznLyuBDRg6d=t6ejtsxJrceLT4Na-YuCmoEWQeZw@mail.gmail.com>

Ask Google the following:

how to set Incoming MIDI Velocities to fixed value using SONAR

On Tue, Dec 23, 2025 at 9:27?AM Shawn Rakestraw via Synth-diy <
synth-diy at synth-diy.org> wrote:

> If I were you, I would look for a solution within your DAW rather than in
> hardware form. I am not familiar with Sonar at all, so I can't be specific,
> but in other DAWs, there are usually plugins that allow all sorts of MIDI
> note manipulation. You usually just place the MIDI plugin immediately
> before your synth plugin. You could even place a few in a row, like a
> plugin that creates chords from single notes and then another that makes
> arpeggios from those chords.
>
> On Tue, Dec 23, 2025 at 11:06?AM Jean-Pierre Desrochers via Synth-diy <
> synth-diy at synth-diy.org> wrote:
>
>> I mostly use Arturia 2025.4 V Collection plugins and I did not find any
>> settings that would do that..
>>
>> -----Message d'origine-----
>> De : Synth-diy <synth-diy-bounces at synth-diy.org> De la part de David
>> Moylan
>> via Synth-diy
>> Envoy? : 23 d?cembre 2025 11:01
>> ? : synth-diy at synth-diy.org
>> Objet : Re: [sdiy] Software that intercepts MIDI notes and readjust
>> velocity
>> values to a fixed value.. ?
>>
>> Hmm, don't the synth plugins have options to ignore velocity?
>>
>> On 12/23/25 10:53 AM, Jean-Pierre Desrochers via Synth-diy wrote:
>> > I'm using a small M-AUDIO Keystation61 MK3 MIDI keyboard to record
>> > notes in my Sonar X3 DAW.
>> > I'm connected through USB cable and it works fine.
>> > Since I'm not a keyboard player I'm not used to velocity playing
>> 'awareness'
>> > so I get many different velocity recorded while I play this keyboard.
>> > This can be annoying when I play organ or some synth plugins.
>> > So.. I'd like to 'fix' all the MIDI notes to full velocity when I
>> > desire it but I could,nt find a way to do it.
>> > Sonar as no MIDI settings for velocity that I could fix to 127 (max)
>> > So I need a third party utility that would 'intercepts' and correct
>> > the incoming MIDI notes And readjust the velocities before reaching to
>> my
>> DAW.
>> > My keyboard has both USB and DIN 5pins MIDI out connectors.
>> > I could build a small box with MIDI IN/OUT that would do the velocity
>> > correction but to me it's like re-inventing the wheel.
>> > I do prefer to stick with my USB cable only but will not go to USB
>> > programing requirements for an external box I would build.
>> > I found this but I'm not sure if it's what I need:
>> > https://plugins4free.com/plugin/2154/
>> >
>> > So.. any suggestions for a small application that would do that ?
>> >
>> >
>> >
>> >
>> > ________________________________________________________
>> > This is the Synth-diy mailing list
>> > Submit email to: Synth-diy at synth-diy.org View archive at:
>> > https://synth-diy.org/pipermail/synth-diy/
>> > Check your settings at:
>> > https://synth-diy.org/mailman/listinfo/synth-diy
>> > Selling or trading? Use marketplace at synth-diy.org
>>
>>
>> --
>> David Moylan
>> Expedition Electronics
>> sonic adventures!
>>
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org View archive at:
>> https://synth-diy.org/pipermail/synth-diy/
>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org
>>
>>
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org
>> View archive at: https://synth-diy.org/pipermail/synth-diy/
>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org
>>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
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From mbryant at futurehorizons.com  Tue Dec 23 19:05:42 2025
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Tue, 23 Dec 2025 18:05:42 +0000
Subject: [sdiy] Software that intercepts MIDI notes and readjust
 velocity values to a fixed value.. ?
In-Reply-To: <000001dc7424$51ea0c50$f5be24f0$@oricom.ca>
References: <002d01dba412$077a6530$166f2f90$@oricom.ca>
 <44a9d773-6a4b-458f-9f3a-ed806b6874d8@go2.pl>
 <000001dc7424$51ea0c50$f5be24f0$@oricom.ca>
Message-ID: <LO6P265MB71331E5702921B0438DEE790DBB5A@LO6P265MB7133.GBRP265.PROD.OUTLOOK.COM>

Download the M-Audio Control Center software for that keyboard and you should be able to adjust the velocity curve to something like an on/off square.
________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Jean-Pierre Desrochers via Synth-diy <synth-diy at synth-diy.org>
Sent: 23 December 2025 15:53
To: Synth-diy at synth-diy.org <Synth-diy at synth-diy.org>
Subject: [sdiy] Software that intercepts MIDI notes and readjust velocity values to a fixed value.. ?

I'm using a small M-AUDIO Keystation61 MK3 MIDI keyboard
to record notes in my Sonar X3 DAW.
I'm connected through USB cable and it works fine.
Since I'm not a keyboard player I'm not used to velocity playing  'awareness'
so I get many different velocity recorded while I play this keyboard.
This can be annoying when I play organ or some synth plugins.
So.. I'd like to 'fix' all the MIDI notes to full velocity when I desire it
but I could,nt find a way to do it.
Sonar as no MIDI settings for velocity that I could fix to 127 (max)
So I need a third party utility that would 'intercepts' and correct the incoming MIDI notes
And readjust the velocities before reaching to my DAW.
My keyboard has both USB and DIN 5pins MIDI out connectors.
I could build a small box with MIDI IN/OUT that would do the velocity correction
but to me it's like re-inventing the wheel.
I do prefer to stick with my USB cable only but will not go to USB programing requirements
for an external box I would build.
I found this but I'm not sure if it's what I need: https://plugins4free.com/plugin/2154/

So.. any suggestions for a small application that would do that ?




________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org
View archive at: https://synth-diy.org/pipermail/synth-diy/
Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
Selling or trading? Use marketplace at synth-diy.org
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From eric at ericframpton.com  Tue Dec 23 19:30:57 2025
From: eric at ericframpton.com (Eric Frampton)
Date: Tue, 23 Dec 2025 18:30:57 +0000
Subject: [sdiy] Software that intercepts MIDI notes and readjust
 velocity values to a fixed value.. ?
In-Reply-To: <LO6P265MB71331E5702921B0438DEE790DBB5A@LO6P265MB7133.GBRP265.PROD.OUTLOOK.COM>
References: <LO6P265MB71331E5702921B0438DEE790DBB5A@LO6P265MB7133.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <996BF0C1-53FA-4EA1-82B0-A70899BAD1EC@ericframpton.com>

If you?re on a Mac, I think MIDIpipe does this

Sent from a device with tiny keys.

On Dec 23, 2025, at 1:07?PM, Mike Bryant <mbryant at futurehorizons.com> wrote:

?
Download the M-Audio Control Center software for that keyboard and you should be able to adjust the velocity curve to something like an on/off square.
________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Jean-Pierre Desrochers via Synth-diy <synth-diy at synth-diy.org>
Sent: 23 December 2025 15:53
To: Synth-diy at synth-diy.org <Synth-diy at synth-diy.org>
Subject: [sdiy] Software that intercepts MIDI notes and readjust velocity values to a fixed value.. ?

I'm using a small M-AUDIO Keystation61 MK3 MIDI keyboard
to record notes in my Sonar X3 DAW.
I'm connected through USB cable and it works fine.
Since I'm not a keyboard player I'm not used to velocity playing  'awareness'
so I get many different velocity recorded while I play this keyboard.
This can be annoying when I play organ or some synth plugins.
So.. I'd like to 'fix' all the MIDI notes to full velocity when I desire it
but I could,nt find a way to do it.
Sonar as no MIDI settings for velocity that I could fix to 127 (max)
So I need a third party utility that would 'intercepts' and correct the incoming MIDI notes
And readjust the velocities before reaching to my DAW.
My keyboard has both USB and DIN 5pins MIDI out connectors.
I could build a small box with MIDI IN/OUT that would do the velocity correction
but to me it's like re-inventing the wheel.
I do prefer to stick with my USB cable only but will not go to USB programing requirements
for an external box I would build.
I found this but I'm not sure if it's what I need: https://plugins4free.com/plugin/2154/

So.. any suggestions for a small application that would do that ?




________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org
View archive at: https://synth-diy.org/pipermail/synth-diy/
Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
Selling or trading? Use marketplace at synth-diy.org
________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org
View archive at: https://synth-diy.org/pipermail/synth-diy/
Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
Selling or trading? Use marketplace at synth-diy.org
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From brianw at audiobanshee.com  Tue Dec 23 19:31:42 2025
From: brianw at audiobanshee.com (brianw)
Date: Tue, 23 Dec 2025 10:31:42 -0800
Subject: [sdiy] Software that intercepts MIDI notes and readjust
 velocity values to a fixed value.. ?
In-Reply-To: <000001dc7424$51ea0c50$f5be24f0$@oricom.ca>
References: <002d01dba412$077a6530$166f2f90$@oricom.ca>
 <44a9d773-6a4b-458f-9f3a-ed806b6874d8@go2.pl>
 <000001dc7424$51ea0c50$f5be24f0$@oricom.ca>
Message-ID: <A03CF9A0-5E25-4CA7-A419-EA523119970A@audiobanshee.com>

Logic Studio Pro has what they call the Environment, which allows all kinds of manipulations of MIDI data.

I realize that you are using Sonar X3, but Logic would allow you to accomplish your goal without any hardware or extra software.

Brian


On Dec 23, 2025, at 7:53 AM, Jean-Pierre Desrochers wrote:
> I'm using a small M-AUDIO Keystation61 MK3 MIDI keyboard
> to record notes in my Sonar X3 DAW.
> I'm connected through USB cable and it works fine.
> Since I'm not a keyboard player I'm not used to velocity playing  'awareness'
> so I get many different velocity recorded while I play this keyboard.
> This can be annoying when I play organ or some synth plugins.
> So.. I'd like to 'fix' all the MIDI notes to full velocity when I desire it
> but I could,nt find a way to do it.
> Sonar as no MIDI settings for velocity that I could fix to 127 (max)
> So I need a third party utility that would 'intercepts' and correct the incoming MIDI notes
> And readjust the velocities before reaching to my DAW.
> My keyboard has both USB and DIN 5pins MIDI out connectors.
> I could build a small box with MIDI IN/OUT that would do the velocity correction
> but to me it's like re-inventing the wheel.
> I do prefer to stick with my USB cable only but will not go to USB programing requirements
> for an external box I would build.
> I found this but I'm not sure if it's what I need: https://plugins4free.com/plugin/2154/
> 
> So.. any suggestions for a small application that would do that ?



From jpdesroc at oricom.ca  Tue Dec 23 19:34:28 2025
From: jpdesroc at oricom.ca (jpdesroc at oricom.ca)
Date: Tue, 23 Dec 2025 13:34:28 -0500
Subject: [sdiy] Software that intercepts MIDI notes and readjust
 velocity values to a fixed value.. ?
In-Reply-To: <LO6P265MB71331E5702921B0438DEE790DBB5A@LO6P265MB7133.GBRP265.PROD.OUTLOOK.COM>
References: <002d01dba412$077a6530$166f2f90$@oricom.ca>
 <44a9d773-6a4b-458f-9f3a-ed806b6874d8@go2.pl>
 <000001dc7424$51ea0c50$f5be24f0$@oricom.ca>
 <LO6P265MB71331E5702921B0438DEE790DBB5A@LO6P265MB7133.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <000901dc743a$c64c0bf0$52e423d0$@oricom.ca>

No ?M-Audio Control Center? or something similar available on their web
site..

 

De : Mike Bryant <mbryant at futurehorizons.com> 
Envoy? : 23 d?cembre 2025 13:06
? : Synth-diy at synth-diy.org; jpdesroc at oricom.ca
Objet : Re: [sdiy] Software that intercepts MIDI notes and readjust velocity
values to a fixed value.. ?

 

Download the M-Audio Control Center software for that keyboard and you
should be able to adjust the velocity curve to something like an on/off
square.

  _____  

From: Synth-diy <synth-diy-bounces at synth-diy.org
<mailto:synth-diy-bounces at synth-diy.org> > on behalf of Jean-Pierre
Desrochers via Synth-diy <synth-diy at synth-diy.org
<mailto:synth-diy at synth-diy.org> >
Sent: 23 December 2025 15:53
To: Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
<Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org> >
Subject: [sdiy] Software that intercepts MIDI notes and readjust velocity
values to a fixed value.. ? 

 

I'm using a small M-AUDIO Keystation61 MK3 MIDI keyboard
to record notes in my Sonar X3 DAW.
I'm connected through USB cable and it works fine.
Since I'm not a keyboard player I'm not used to velocity playing
'awareness'
so I get many different velocity recorded while I play this keyboard.
This can be annoying when I play organ or some synth plugins.
So.. I'd like to 'fix' all the MIDI notes to full velocity when I desire it
but I could,nt find a way to do it.
Sonar as no MIDI settings for velocity that I could fix to 127 (max)
So I need a third party utility that would 'intercepts' and correct the
incoming MIDI notes
And readjust the velocities before reaching to my DAW.
My keyboard has both USB and DIN 5pins MIDI out connectors.
I could build a small box with MIDI IN/OUT that would do the velocity
correction
but to me it's like re-inventing the wheel.
I do prefer to stick with my USB cable only but will not go to USB
programing requirements
for an external box I would build.
I found this but I'm not sure if it's what I need:
https://plugins4free.com/plugin/2154/

So.. any suggestions for a small application that would do that ?




________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org> 
View archive at: https://synth-diy.org/pipermail/synth-diy/
Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
Selling or trading? Use marketplace at synth-diy.org
<mailto:marketplace at synth-diy.org> 

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From grant at musictechnologiesgroup.com  Tue Dec 23 19:38:28 2025
From: grant at musictechnologiesgroup.com (grant musictechnologiesgroup.com)
Date: Tue, 23 Dec 2025 18:38:28 +0000
Subject: [sdiy] Software that intercepts MIDI notes and readjust
 velocity values to a fixed value.. ?
In-Reply-To: <CA+-UNiCi4ZN-w-DEYRYk+QBN0J0eYW8kPGE42OjceiVHum0b2g@mail.gmail.com>
References: <002d01dba412$077a6530$166f2f90$@oricom.ca>
 <44a9d773-6a4b-458f-9f3a-ed806b6874d8@go2.pl>
 <000001dc7424$51ea0c50$f5be24f0$@oricom.ca>
 <c25b3b5a-0795-4c01-8cb4-cc97210feafa@expeditionelectronics.com>
 <000101dc7425$b26074b0$17215e10$@oricom.ca>
 <CA+-UNiCi4ZN-w-DEYRYk+QBN0J0eYW8kPGE42OjceiVHum0b2g@mail.gmail.com>
Message-ID: <8123956d-3f11-4cd0-9ad4-5b8c8647753a@musictechnologiesgroup.com>

On 12/23/2025 8:24 AM, Shawn Rakestraw via Synth-diy wrote:
> If I were you, I would look for a solution within your DAW rather than 
> in hardware form...

Heresy. USB MIDI Host to 5-pin DIN, then to MIDI Solutions Velocity 
Converter box, finally to MIDI-to-USB adapter/cable.

GB


From jpdesroc at oricom.ca  Tue Dec 23 19:41:34 2025
From: jpdesroc at oricom.ca (jpdesroc at oricom.ca)
Date: Tue, 23 Dec 2025 13:41:34 -0500
Subject: [sdiy] Software that intercepts MIDI notes and readjust
 velocity values to a fixed value.. ?
In-Reply-To: <LO6P265MB71331E5702921B0438DEE790DBB5A@LO6P265MB7133.GBRP265.PROD.OUTLOOK.COM>
References: <002d01dba412$077a6530$166f2f90$@oricom.ca>
 <44a9d773-6a4b-458f-9f3a-ed806b6874d8@go2.pl>
 <000001dc7424$51ea0c50$f5be24f0$@oricom.ca>
 <LO6P265MB71331E5702921B0438DEE790DBB5A@LO6P265MB7133.GBRP265.PROD.OUTLOOK.COM>
Message-ID: <000e01dc743b$c3bbceb0$4b336c10$@oricom.ca>

Got it !

 

There is MIDI FX plugin called ?Velocity? that just needs
to be placed in the incoming MIDI track and set to a fixed value of 127 (in
my case)

 

Thanks to all of you.

 

De : Mike Bryant <mbryant at futurehorizons.com> 
Envoy? : 23 d?cembre 2025 13:06
? : Synth-diy at synth-diy.org; jpdesroc at oricom.ca
Objet : Re: [sdiy] Software that intercepts MIDI notes and readjust velocity
values to a fixed value.. ?

 

Download the M-Audio Control Center software for that keyboard and you
should be able to adjust the velocity curve to something like an on/off
square.

  _____  

From: Synth-diy <synth-diy-bounces at synth-diy.org
<mailto:synth-diy-bounces at synth-diy.org> > on behalf of Jean-Pierre
Desrochers via Synth-diy <synth-diy at synth-diy.org
<mailto:synth-diy at synth-diy.org> >
Sent: 23 December 2025 15:53
To: Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
<Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org> >
Subject: [sdiy] Software that intercepts MIDI notes and readjust velocity
values to a fixed value.. ? 

 

I'm using a small M-AUDIO Keystation61 MK3 MIDI keyboard
to record notes in my Sonar X3 DAW.
I'm connected through USB cable and it works fine.
Since I'm not a keyboard player I'm not used to velocity playing
'awareness'
so I get many different velocity recorded while I play this keyboard.
This can be annoying when I play organ or some synth plugins.
So.. I'd like to 'fix' all the MIDI notes to full velocity when I desire it
but I could,nt find a way to do it.
Sonar as no MIDI settings for velocity that I could fix to 127 (max)
So I need a third party utility that would 'intercepts' and correct the
incoming MIDI notes
And readjust the velocities before reaching to my DAW.
My keyboard has both USB and DIN 5pins MIDI out connectors.
I could build a small box with MIDI IN/OUT that would do the velocity
correction
but to me it's like re-inventing the wheel.
I do prefer to stick with my USB cable only but will not go to USB
programing requirements
for an external box I would build.
I found this but I'm not sure if it's what I need:
https://plugins4free.com/plugin/2154/

So.. any suggestions for a small application that would do that ?




________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org> 
View archive at: https://synth-diy.org/pipermail/synth-diy/
Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
Selling or trading? Use marketplace at synth-diy.org
<mailto:marketplace at synth-diy.org> 

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From mbryant at futurehorizons.com  Tue Dec 23 20:51:16 2025
From: mbryant at futurehorizons.com (Mike Bryant)
Date: Tue, 23 Dec 2025 19:51:16 +0000
Subject: [sdiy] Software that intercepts MIDI notes and readjust
 velocity values to a fixed value.. ?
In-Reply-To: <000901dc743a$c64c0bf0$52e423d0$@oricom.ca>
References: <002d01dba412$077a6530$166f2f90$@oricom.ca>
 <44a9d773-6a4b-458f-9f3a-ed806b6874d8@go2.pl>
 <000001dc7424$51ea0c50$f5be24f0$@oricom.ca>
 <LO6P265MB71331E5702921B0438DEE790DBB5A@LO6P265MB7133.GBRP265.PROD.OUTLOOK.COM>
 <000901dc743a$c64c0bf0$52e423d0$@oricom.ca>
Message-ID: <LO6P265MB71335CFD4BE41853B37766FBDBB5A@LO6P265MB7133.GBRP265.PROD.OUTLOOK.COM>

I think you need to register and sign in, then it appears under "My Products".
It also used to come on a CD with the keyboard but I suspect not nowadays
________________________________
From: jpdesroc at oricom.ca <jpdesroc at oricom.ca>
Sent: 23 December 2025 18:34
To: Mike Bryant <mbryant at futurehorizons.com>; Synth-diy at synth-diy.org <Synth-diy at synth-diy.org>
Subject: RE: [sdiy] Software that intercepts MIDI notes and readjust velocity values to a fixed value.. ?


No ?M-Audio Control Center? or something similar available on their web site..



De : Mike Bryant <mbryant at futurehorizons.com>
Envoy? : 23 d?cembre 2025 13:06
? : Synth-diy at synth-diy.org; jpdesroc at oricom.ca
Objet : Re: [sdiy] Software that intercepts MIDI notes and readjust velocity values to a fixed value.. ?



Download the M-Audio Control Center software for that keyboard and you should be able to adjust the velocity curve to something like an on/off square.

________________________________

From: Synth-diy <synth-diy-bounces at synth-diy.org<mailto:synth-diy-bounces at synth-diy.org>> on behalf of Jean-Pierre Desrochers via Synth-diy <synth-diy at synth-diy.org<mailto:synth-diy at synth-diy.org>>
Sent: 23 December 2025 15:53
To: Synth-diy at synth-diy.org<mailto:Synth-diy at synth-diy.org> <Synth-diy at synth-diy.org<mailto:Synth-diy at synth-diy.org>>
Subject: [sdiy] Software that intercepts MIDI notes and readjust velocity values to a fixed value.. ?



I'm using a small M-AUDIO Keystation61 MK3 MIDI keyboard
to record notes in my Sonar X3 DAW.
I'm connected through USB cable and it works fine.
Since I'm not a keyboard player I'm not used to velocity playing  'awareness'
so I get many different velocity recorded while I play this keyboard.
This can be annoying when I play organ or some synth plugins.
So.. I'd like to 'fix' all the MIDI notes to full velocity when I desire it
but I could,nt find a way to do it.
Sonar as no MIDI settings for velocity that I could fix to 127 (max)
So I need a third party utility that would 'intercepts' and correct the incoming MIDI notes
And readjust the velocities before reaching to my DAW.
My keyboard has both USB and DIN 5pins MIDI out connectors.
I could build a small box with MIDI IN/OUT that would do the velocity correction
but to me it's like re-inventing the wheel.
I do prefer to stick with my USB cable only but will not go to USB programing requirements
for an external box I would build.
I found this but I'm not sure if it's what I need: https://plugins4free.com/plugin/2154/

So.. any suggestions for a small application that would do that ?




________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org<mailto:Synth-diy at synth-diy.org>
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From johnspeth at yahoo.com  Wed Dec 24 20:42:23 2025
From: johnspeth at yahoo.com (John Speth)
Date: Wed, 24 Dec 2025 19:42:23 +0000 (UTC)
Subject: [sdiy] Software that intercepts MIDI notes and readjust
 velocity values to a fixed value.. ?
In-Reply-To: <000e01dc743b$c3bbceb0$4b336c10$@oricom.ca>
References: <002d01dba412$077a6530$166f2f90$@oricom.ca>
 <44a9d773-6a4b-458f-9f3a-ed806b6874d8@go2.pl>
 <000001dc7424$51ea0c50$f5be24f0$@oricom.ca>
 <LO6P265MB71331E5702921B0438DEE790DBB5A@LO6P265MB7133.GBRP265.PROD.OUTLOOK.COM>
 <000e01dc743b$c3bbceb0$4b336c10$@oricom.ca>
Message-ID: <1019855362.3434701.1766605343400@mail.yahoo.com>

 A tool I've used a lot for your kind of problem is Midiox. Use the programmable filters. That feature takes a little experimentation to get right. You'll need to use virtual MIDI ports like loopmidi so you have a MIDI chain for processing.
    On Tuesday, December 23, 2025 at 12:00:31 PM PST, Jean-Pierre Desrochers via Synth-diy <synth-diy at synth-diy.org> wrote:  
 
 
Got it !

 ?

There is MIDI FX plugin called ?Velocity? that just needs
to be placed in the incoming MIDI track and set to a fixed value of 127 (in my case)

 ?

Thanks to all of you.

 ?

De?: Mike Bryant <mbryant at futurehorizons.com> 
Envoy??: 23 d?cembre 2025 13:06
??: Synth-diy at synth-diy.org; jpdesroc at oricom.ca
Objet?: Re: [sdiy] Software that intercepts MIDI notes and readjust velocity values to a fixed value.. ?

 ?

Download the M-Audio Control Center software for that keyboard and you should be able to adjust the velocity curve to something like an on/off square.

From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Jean-Pierre Desrochers via Synth-diy <synth-diy at synth-diy.org>
Sent: 23 December 2025 15:53
To: Synth-diy at synth-diy.org <Synth-diy at synth-diy.org>
Subject: [sdiy] Software that intercepts MIDI notes and readjust velocity values to a fixed value.. ? 

?

I'm using a small M-AUDIO Keystation61 MK3 MIDI keyboard
to record notes in my Sonar X3 DAW.
I'm connected through USB cable and it works fine.
Since I'm not a keyboard player I'm not used to velocity playing? 'awareness'
so I get many different velocity recorded while I play this keyboard.
This can be annoying when I play organ or some synth plugins.
So.. I'd like to 'fix' all the MIDI notes to full velocity when I desire it
but I could,nt find a way to do it.
Sonar as no MIDI settings for velocity that I could fix to 127 (max)
So I need a third party utility that would 'intercepts' and correct the incoming MIDI notes
And readjust the velocities before reaching to my DAW.
My keyboard has both USB and DIN 5pins MIDI out connectors.
I could build a small box with MIDI IN/OUT that would do the velocity correction
but to me it's like re-inventing the wheel.
I do prefer to stick with my USB cable only but will not go to USB programing requirements
for an external box I would build.
I found this but I'm not sure if it's what I need: https://plugins4free.com/plugin/2154/

So.. any suggestions for a small application that would do that ?




________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org
View archive at: https://synth-diy.org/pipermail/synth-diy/
Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
Selling or trading? Use marketplace at synth-diy.org
________________________________________________________
This is the Synth-diy mailing list
Submit email to: Synth-diy at synth-diy.org
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From jacobwatters at gmail.com  Thu Dec 25 20:46:14 2025
From: jacobwatters at gmail.com (Jacob Watters)
Date: Thu, 25 Dec 2025 14:46:14 -0500
Subject: [sdiy] Software that intercepts MIDI notes and readjust
 velocity values to a fixed value.. ?
In-Reply-To: <1019855362.3434701.1766605343400@mail.yahoo.com>
References: <002d01dba412$077a6530$166f2f90$@oricom.ca>
 <44a9d773-6a4b-458f-9f3a-ed806b6874d8@go2.pl>
 <000001dc7424$51ea0c50$f5be24f0$@oricom.ca>
 <LO6P265MB71331E5702921B0438DEE790DBB5A@LO6P265MB7133.GBRP265.PROD.OUTLOOK.COM>
 <000e01dc743b$c3bbceb0$4b336c10$@oricom.ca>
 <1019855362.3434701.1766605343400@mail.yahoo.com>
Message-ID: <CAKcdib0uFrUe0EJ2nR4nrSiSFzDW-svVGS8cVhsMKAjsDhQjeg@mail.gmail.com>

If you are looking for a hardware solution, that would be easy to do with
an arduino. I used an old keybed and an arduino with an LED display and a
pot to create my own MIDI controller that allows me to manually dial in the
velocity. You could omit the keybed, and just have the arduino replace the
velocity with the desired level.

*Jacob Watters*
JacobWatters.com <http://jacobwatters.com/>


On Wed, Dec 24, 2025 at 2:45?PM John Speth via Synth-diy <
synth-diy at synth-diy.org> wrote:

> A tool I've used a lot for your kind of problem is Midiox. Use the
> programmable filters. That feature takes a little experimentation to get
> right. You'll need to use virtual MIDI ports like loopmidi so you have a
> MIDI chain for processing.
>
> On Tuesday, December 23, 2025 at 12:00:31 PM PST, Jean-Pierre Desrochers
> via Synth-diy <synth-diy at synth-diy.org> wrote:
>
>
> Got it !
>
>
>
> There is MIDI FX plugin called ?Velocity? that just needs
> to be placed in the incoming MIDI track and set to a fixed value of 127
> (in my case)
>
>
>
> Thanks to all of you.
>
>
>
> *De :* Mike Bryant <mbryant at futurehorizons.com>
> *Envoy? :* 23 d?cembre 2025 13:06
> *? :* Synth-diy at synth-diy.org; jpdesroc at oricom.ca
> *Objet :* Re: [sdiy] Software that intercepts MIDI notes and readjust
> velocity values to a fixed value.. ?
>
>
>
> Download the M-Audio Control Center software for that keyboard and you
> should be able to adjust the velocity curve to something like an on/off
> square.
> ------------------------------
>
> *From:* Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of
> Jean-Pierre Desrochers via Synth-diy <synth-diy at synth-diy.org>
> *Sent:* 23 December 2025 15:53
> *To:* Synth-diy at synth-diy.org <Synth-diy at synth-diy.org>
> *Subject:* [sdiy] Software that intercepts MIDI notes and readjust
> velocity values to a fixed value.. ?
>
>
>
> I'm using a small M-AUDIO Keystation61 MK3 MIDI keyboard
> to record notes in my Sonar X3 DAW.
> I'm connected through USB cable and it works fine.
> Since I'm not a keyboard player I'm not used to velocity playing
> 'awareness'
> so I get many different velocity recorded while I play this keyboard.
> This can be annoying when I play organ or some synth plugins.
> So.. I'd like to 'fix' all the MIDI notes to full velocity when I desire it
> but I could,nt find a way to do it.
> Sonar as no MIDI settings for velocity that I could fix to 127 (max)
> So I need a third party utility that would 'intercepts' and correct the
> incoming MIDI notes
> And readjust the velocities before reaching to my DAW.
> My keyboard has both USB and DIN 5pins MIDI out connectors.
> I could build a small box with MIDI IN/OUT that would do the velocity
> correction
> but to me it's like re-inventing the wheel.
> I do prefer to stick with my USB cable only but will not go to USB
> programing requirements
> for an external box I would build.
> I found this but I'm not sure if it's what I need:
> https://plugins4free.com/plugin/2154/
>
> So.. any suggestions for a small application that would do that ?
>
>
>
>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
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