Yahoo Groups archive
Messages
Page 1 of 5 · 201 messages matched
2026-03-31 by Ben Stuyts
Hi all, When Yahoo shut down their groups section, I started a project to archive some groups and put them on the synth-diy.org site. Florian was extremely helpful in creating the scripts to create web pages from the archived messages. In response I also received lots of archives
2026-03-31 by ShedSynth
Thank you Nicolás. I now have all six PDFs from another kind source; very grateful for your help. If anybody is interested, here’s my progress so far: https://shedsynth.wordpress.com/2026/03/24/tandberg-115/ From: Nicolás Dinapoli Fariña Sent: 31 March 2026 03:01 To: ShedSynth Su
2026-03-30 by S Ridley
JL Cooper has been bought by TSL https://www.production-expert.com/production-expert-1/tsl-acquires-jlcooper-electronics On Fri, 6 Mar 2026 at 00:40, Michael E Caloroso via Synth-diy synth-diy@synth-diy.org > wrote: Jim Cooper made some great MIDI tools. I have three MSB+ in my s
2026-03-30 by Jimmy Moore
On Sat, Mar 28, 2026 at 3:22 PM Richie Burnett rburnett@richieburnett.co.uk > wrote: I would have said that those strange squeaking sounds were likely beating between the high-frequency BBD clocks in the chorus section, but you said it's audible on the audio before if goes into t
2026-03-29 by ShedSynth
Hi, is anybody here also on HiFiEngine? I'm looking for service documentation to help me get a Tandberg Series 115 instrumentation recorder working. HiFiEngine has these files, but the site is currently closed to new user account registrations: https://www.hifiengine.com/hfe_down
2026-03-28 by The SynthiMuse
Hi Tom Up in Scotty-land, we've had two phantom springs so far. One more short winter to come and it'll be cruising in to the real spring, with any luck. :-) Gerry On Sat, 28 Mar 2026, 21:38 Tom Wiltshire, tom@electricdruid.net > wrote: > On 28 Mar 2026, at 21:22, Richie Burnett
2026-03-28 by Tom Wiltshire
> On 28 Mar 2026, at 21:22, Richie Burnett wrote: > > Are Polysix synths particularly prone to battery leakage damage? I have a friend who is also currently grappling with some really quite extensive corrosion issues due to a leaked battery in a Polysix! Hi Richie, Yes, they're a
2026-03-28 by Jimmy Moore
Great catch, I hadn't listened too critically back to back. Here are two recordings where you can clearly hear that the noisehas higher frequencies when the note is playing Not playing: https://drive.google.com/file/d/1eYx_YXt7WBBX25fwzZ2FOYc6I9fTDbf0/view?usp=drivesdk Droning no
2026-03-28 by Richie Burnett
I would have said that those strange squeaking sounds were likely beating between the high-frequency BBD clocks in the chorus section, but you said it's audible on the audio before if goes into the effects section. The squeaking sound just sounds similar to the swooshing that you
2026-03-28 by Nicolás Dinapoli Fariña
Here it is, Florian. Please do upload it.I also have a few PDFs nobody else has. Can I send them to upload to tour site? El sáb., 28 de mar. de 2026 a la(s) 5:51, Florian Anwander escribió: Hi Oh! I'd be interested in the file too. And I could provide it on my web site. Best rega
2026-03-28 by Florian Anwander
Hi Oh! I'd be interested in the file too. And I could provide it on my web site. Best regards Florian Am 28.03.26 um 06:04 schrieb Dakota Melin via Synth-diy: Hi, I have a copy that I downloaded recently if you want it, I think I'd have to send it to you directly off list though?
2026-03-28 by Dakota Melin
Hi, I have a copy that I downloaded recently if you want it, I think I'd have to send it to you directly off list though? Incidentally, I was searching for some info on a weird fault some days ago for the Crumar and other instruments that use the TDA1008. Some notes seemed to be
2026-03-28 by Nicolás Dinapoli Fariña
Hello everyone. Does anybody know where I can download the Crumar Perdormer version 2 manual? There are subtle differences besides the filter board with version 1. Thank you.
2026-03-28 by el macaco
Hi Jimmy, Not familiar with these circuits, but if the corrosion traveled up the traces to other boards I’ve read that it is very difficult to remove and if I remember correctly someone made new boards to replace corrosion damaged ones. If the 324 is an amplifying stage it could
2026-03-27 by Adam (synthDIY)
On 28 Mar 2026, at 00:50, Jimmy Moore wrote: Modifying the filter cutoff or resonance does NOT change the noise timbre. There may be a slight relationship between changing the resonance and that triggering the the noise. But only very slight. But you'll agree that in your example
2026-03-27 by Jimmy Moore
I can't wait when I figure out where it's coming from so I can figure out how to patch it in as a reliable effect haha! Florian and a few others on AH said it sounded like a flaky transistor or BBD chip. Modifying the filter cutoff or resonance does NOT change the noise timbre. T
2026-03-27 by Adam (synthDIY)
Interesting noise! Sounds to me like the noise is being affected by the filter - would you agree? If so, it's not coming from the Effect Board BBD A
2026-03-27 by Jimmy Moore
Forwarding here because I feel like this is the better audience to help diagnose korg polysix issues. Quick recap:I have already replaced the cpu board and psu with a synthronicss kit.. There's still noise, which sounds like this: https://drive.google.com/file/d/14MpNs5ZL6Ze7kJ5b
2026-03-24 by Jay Schwichtenberg
Thanks for the feedback Mike. � Jay S On 03/22/2026 8:48 PM PDT Mike Beauchamp list@mikebeauchamp.com > wrote: � � Just a 3-month-later follow up to this... info below.. � On 2025-12-13 19:59, Jay Schwichtenberg via Synth-diy wrote: Looking at the EDN schematic again I think ther
2026-03-23 by Gordonjcp
On Sun, Mar 22, 2026 at 06:11:27PM -0700, brianw wrote: > > Placing a CPU between the keyboard scan and the VCO input, so that sequencing and transposing are simple to achieve? > It's not just that, it's also so that CV is simple to achieve. It's far cheaper and easier to use a C
2026-03-23 by Michael E Caloroso
> I believe that reading multiple notes from a keyboard for polyphonic voice assignment requires a CPU. At the very least it requires matrix wiring of the keys, some sort of digital scan, > and a method to deliver a unique pitch CV to a selected voice. That's probably extremely d
2026-03-23 by Mike Beauchamp
Just a 3-month-later follow up to this... info below.. 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
2026-03-23 by Olav Kvern
Brian Willoughby wrote: "Which aspects of the Pro-One DAC design do you consider to be clever?" All of the above! ...which reminds me, I need to open mine up to replace the Oscillator 1 octave switch. I walked through miles of orchards to get to the SCI office to pick up a copy o
2026-03-23 by brianw
Thanks for mentioning the Pro-One DAC, Olav, because I had not looked at these details before (and I own one!) Which aspects of the Pro-One DAC design do you consider to be clever? Choosing an 8-bit DAC, but only engaging the upper 6 bits? Stealing the 6-column 8021 Port 0 output
2026-03-22 by Olav Kvern
The Sequential Pro-One is another mono synth with a DAC. I still think that the way it's done is clever. Thanks, Ole On 3/22/26 7:12 AM, Michael E Caloroso via Synth-diy wrote: > > Correct me if I'm wrong but old synths using DAC for CV were all > > polyphonic. > > If it was prog
2026-03-22 by Michael E Caloroso
> Correct me if I'm wrong but old synths using DAC for CV were all > polyphonic. If it was programmable using solid state memory, it had DAC with MUX/S&H. Not limited to just polyphonics. Oberheim OB-1 monophonic was programmable and used a DAC with MUX/S&H for CV. Released in 19
2026-03-22 by Ben Stuyts
Hi all, I have changed some rules in the spam filtering of this list. (Getting so tired of all that china spam…) Please let me know if you find that your emails are blocked here and I’ll fix it. (Send me an email at ben@stuyts.nl ). Thanks, Ben
2026-03-21 by Magnus Mauritz
I always assumed you could multiplex output of an exponential converter. Cool that it was done. On 3/21/26 12:18 PM, Gordonjcp wrote: > On Fri, Mar 20, 2026 at 10:40:57PM +0000, Tom Wiltshire wrote: >> The Korg Polysix kind-of was. The VCOs were linear, and there was an expo conv
2026-03-21 by Gordonjcp
On Fri, Mar 20, 2026 at 10:40:57PM +0000, Tom Wiltshire wrote: > The Korg Polysix kind-of was. The VCOs were linear, and there was an expo convertor that was multiplexed out to each of them, if I remember. There's a schematic I drew of the VCO design flying around on the web. > H
2026-03-21 by Roman Sowa
You can safely assume EVERY vintage Korg and Yamaha synth was linear VCO. Check the most classic linear VCO from Korg MS-20 for an inspiration. It was used widely in many synths. I've posted it (and bragged about it) several times already, but since you asked, here's 5V single su
2026-03-21 by Thomas Hudson
Page says closed to health problems.
2026-03-20 by Tom Wiltshire
The Korg Polysix kind-of was. The VCOs were linear, and there was an expo convertor that was multiplexed out to each of them, if I remember. There's a schematic I drew of the VCO design flying around on the web. In that respect, there's a sense in which *many* synth VCOs are line
2026-03-20 by Thomas Hudson
Thanks to everyone on this thread. I am currently working on a MIDI to Hertz program for the Raspberry Pi (though I can probably move to an ESP32). Two last questions. Can anyone tell me which commercial synths were linear response? I know about the Moog Taurus / Behringer Toro.
2026-03-20 by Mike Bryant
Well yes I was actually doing frequencies like 1004Hz (a telecomms test freq) at 8MHz sampling, but as you say the secret with PDM is to stay well away from the peak positive and peak negative values. However a little bit of high frequency noise injection (from a look up table) a
2026-03-20 by Tom Wiltshire
There's also differences in *where* the errors are worst between PWM and PDM. Generally, you worry most about the fundamental and lowest harmonics of the pulse output frequency, since they're the hardest to filter. For PWM, you get the worst fundamental and 3rd harmonic at the mi
2026-03-20 by Mike Bryant
This is why you use PDM, not PWM. The pulses are at much higher frequency and easier to filter to the correct DC level with less noise. From: Synth-diy on behalf of brianw Sent: 20 March 2026 08:22 To: synth-diy@synth-diy.org Subject: Re: [sdiy] Linear response VCOs? The challeng
2026-03-20 by Gordonjcp
On Fri, Mar 20, 2026 at 01:39:35AM -0700, brianw wrote: > I'm not even sure what it means to have a 32-bit DAC, because the noise floor is around the 20-bit level. Extending from 24-bit to 32-bit adds a lot of precision, but absolutely no accuracy is gained. In the olden days whe
2026-03-20 by brianw
Not just overkill, but also not scalable. If you needed 40 CV outputs, you're not going to pay $250 for that. Besides, the R-Pi probably can't keep 5 audio CODEC chips fed properly at 32/384k. I am also suspicious of the DC coupling. 24-bit converters have high precision, but low
2026-03-20 by brianw
Most multi-channel ADC chips (that are not 24-bit delta-sigma) are actually a single ADC with a mux built-in, but without the S&H that you'd see on a DAC. Some even put the output of the mux on a pin next to the ADC input, so that common processing like scaling can be done unifor
2026-03-19 by Thomas Hudson
Very interesting. I just came across two different dc coupled eight channel DAC's for the Raspberry 5 supporting up to 24-bit/192kHz or 32-bit/384k, for around $50, though probably overkill. > On Mar 19, 2026, at 5:11 PM, Tom Wiltshire wrote: > > The whole "Mux and S&H" thing was
2026-03-19 by Tom Wiltshire
The whole "Mux and S&H" thing was only because decent quality DACs were damn expensive, so it was better to buy one good one and re-use it a lot of times. If there'd been a sixteen channel DAC for the same price, you can bet they've have used it. Incidentally, I once worked on a
2026-03-19 by Mike Bryant
Ah okay, the poly requirement makes sense. But we ran PDM DACs at 8MHz using LS-TTL to give better than 16 bit audio for a single channel so you could still feed that to a MUX and S/H. ________________________________ From: Roman Sowa Sent: 19 March 2026 11:10 To: Mike Bryant ; s
2026-03-19 by Roman Sowa
Correct me if I'm wrong but old synths using DAC for CV were all polyhonic. That means a lot of CV sources needed. So they used S&H and muxed DAC. To have PWM with fast enough response to feed MUX and S$H, it would have to run at enormouse frequency, not suitable to affordable te
2026-03-18 by Mike Bryant
Does anybody know why these old synths didn't use PWM/PDM techniques ? LS-TTL or CMOS feeding a comparator into an analogue integrator gave 12 bits performance at audio frequencies even in the 70s so CVs good enough for tuning would have been easy. _______________________________
2026-03-18 by drheqx
I agree Roman. Modern, precision converters are very tight and predictable. We make discrete dac and adc systems at my company. They're indestructible but slow and not as accurate. Mike On Wed, Mar 18, 2026 at 2:58 AM Roman Sowa via Synth-diy synth-diy@synth-diy.org > wrote: Toda
2026-03-18 by brianw
The Prophet 5, Rev 1 and Rev 2, use a 7-bit DAC made from hand-picked resistors. There is a note in the Service Manual that you should *not* replace these resistors because of the challenge of matching a new one to the network. 1 LSB is calibrated to 1/12 V (0.0833 V) for easy us
2026-03-18 by Thomas Hudson
Thanks for mentioning MIDImplant. I wasn’t aware of it. I see it has been discontinued. Are their other similar boards like it available? > On Mar 18, 2026, at 2:54 AM, Roman Sowa via Synth-diy wrote: > > Today I see no point in building PAiA DAC or any other similar solutions, e
2026-03-18 by Tom Wiltshire
Roland had form for this. SH-101 uses a simple DAC built from a few resistors too. Like Roman said, it doesn't really make sense nowadays when DACs are cheap, but it was worth it then. Tom > On 18 Mar 2026, at 11:31, mark verbos via Synth-diy wrote: > > Like a TR-909. > But, sure
2026-03-18 by mark verbos
Like a TR-909. But, surely it is cheaper to use 1% resistors rather than a custom resistor array made. Mark > On Mar 17, 2026, at 18:44, David Manley via Synth-diy wrote: > > It's interesting to see how PAiA's John Simonton solved some these issues in the 1970's by having a custo
2026-03-18 by Roman Sowa
Today I see no point in building PAiA DAC or any other similar solutions, except for nostalgic reasons. Dirt cheap 16-bit commercially available DACs offer much better linearity than any trimmed or selected resistor discrete DAC could ever do. 16-bit DAC in MIDImplant offered no