MOTM

Hi

I´m still a bit new to MOTM and dont have any MOTM VCO´s yet. (using 
my old Korg Mono/Poly as main VCO´s) Can you do FM in the "Yamaha DX7 
way", with it? (feeding/modulating it with its own or another VCO´s 
output) Or is this only possible in a virtual digital domaine?

greetings

Gregory

In order to do DX type FM you need the ability to linearly frequency
modulate a VCO through zero.  While the MOTM-300 is capable of linear
FM, it does not have through zero capability.

I'm unsure whether or not you need oscillators which reset to zero on
the leading edge of a gate.  This may not be necessary, but I assume the
DX series does reset to zero.

Even if the MOTM oscillator was capable of meeting the above criteria,
you would need a very large system to replicate the DX7.  Six VCOs, Six
VCAs, Six Envelope Generators at the minimum.

Personally, I would welcome a new MOTM VCO with these capabilities, but
I haven't heard anyone else except Dave Bradley express the same
sentiments.

Paul H.

-----Original Message-----
From: motm@yahoogroups.com [mailto:motm@yahoogroups.com] On Behalf Of
gregorykjar
Sent: Wednesday, December 07, 2005 1:50 PM
To: motm@yahoogroups.com
Subject: [motm] VCO FM question

Hi

I´m still a bit new to MOTM and dont have any MOTM VCO´s yet. (using 
my old Korg Mono/Poly as main VCO´s) Can you do FM in the "Yamaha DX7 
way", with it? (feeding/modulating it with its own or another VCO´s 
output) Or is this only possible in a virtual digital domaine?

greetings

Gregory






 
Yahoo! Groups Links

You can make FM sounds with MOTM modules, you 
just can't get the precision that you get with a 
digital synth (like DX7) in terms of keeping the 
modulator to carrier ratios precise all the time. 
You can create gongs sounds quite easily, but if 
you manage to tweak the controls to make a good 
FM piano sound at one frequency, it will not 
sound so good with other notes for very long; the 
slightest drift in oscillator frequency (or 
phase) will make it sound like hell. This is 
normal for analogue synths and it wasn't until 
the DX series that useable FM became a reality, 
and for that they had to go digital.

>I´m still a bit new to MOTM and dont have any MOTM VCO´s yet. (using
>my old Korg Mono/Poly as main VCO´s) Can you do FM in the "Yamaha DX7
>way", with it? (feeding/modulating it with its own or another VCO´s
>output) Or is this only possible in a virtual digital domaine?
>

You can do the "feeding/modulating it with its own or another VCO\ufffds output"
thing. Like X-MOD on the Mono/Poly.**

As Paul H. wrote, however, it's a long way from there to doing it the
"Yamaha DX7 way".

It's been widely stated that VCOs are not accurate enough for true, DX-style
FM work, and that is why Yamaha went with DCOs. But maybe it was also a
matter of cost? (Well, we *know* that cost is always a factor.) Question is,
how accurate do the oscillators really have to be?
--
john

** I have a Mo/Po, too. Turned it on the other day for the first time in
months, and it was not tracking in tune. It's been perfect for over 20
years, so I was a little bummed. Hopefully it's just a matter of
calibration, but I'm fearing that caps and/or some CMOS chips are due for
replacement. Not rocket science but it will be hours of work. :-/

----- Original Message ----- 
From: "gregorykjar" <greg@...>
To: <motm@yahoogroups.com>
Sent: Wednesday, December 07, 2005 1:50 PM
Subject: [motm] VCO FM question


Hi

I\ufffdm still a bit new to MOTM and dont have any MOTM VCO\ufffds yet. (using
my old Korg Mono/Poly as main VCO\ufffds) Can you do FM in the "Yamaha DX7
way", with it? (feeding/modulating it with its own or another VCO\ufffds
output) Or is this only possible in a virtual digital domaine?

greetings

Gregory

Hi

Well, I didn´t want to make a complete DX7 replica. You can get a 
long way with just 2 VCO´s, with an EG and a VCA to control the 
feedback/FM. I´ve tried that in Reaktor, but then again thats in the 
virtual world. It would be great with real knobs.

Do you by "through zero" mean that it goes down to zero hertz and 
then through to "negative" (phase reversed?) frequencies? (within 
one cycle)
I realise this is probably not an easy design task. Just wishing :-)

greetings 

Gregory



--- In motm@yahoogroups.com, "Paul Haneberg" <phaneber@o...> wrote:
>
> 
> In order to do DX type FM you need the ability to linearly 
frequency
> modulate a VCO through zero.  While the MOTM-300 is capable of 
linear
> FM, it does not have through zero capability.
> 
> I'm unsure whether or not you need oscillators which reset to zero 
on
> the leading edge of a gate.  This may not be necessary, but I 
assume the
> DX series does reset to zero.
> 
> Even if the MOTM oscillator was capable of meeting the above 
criteria,
> you would need a very large system to replicate the DX7.  Six 
VCOs, Six
> VCAs, Six Envelope Generators at the minimum.
> 
> Personally, I would welcome a new MOTM VCO with these 
capabilities, but
> I haven't heard anyone else except Dave Bradley express the same
> sentiments.
> 
> Paul H.
> 
>   
> 
> 
> -----Original Message-----
> From: motm@yahoogroups.com [mailto:motm@yahoogroups.com] On Behalf 
Of
> gregorykjar
> Sent: Wednesday, December 07, 2005 1:50 PM
> To: motm@yahoogroups.com
> Subject: [motm] VCO FM question
> 
> Hi
> 
> I´m still a bit new to MOTM and dont have any MOTM VCO´s yet. 
(using 
> my old Korg Mono/Poly as main VCO´s) Can you do FM in the "Yamaha 
DX7 
> way", with it? (feeding/modulating it with its own or another 
VCO´s 

> output) Or is this only possible in a virtual digital domaine?
> 
> greetings
> 
> Gregory
> 
> 
> 
> 
> 
> 
>  
> Yahoo! Groups Links
>

Last year my old Mono/Poly hadn´t been turned on for some years 
and was completely dead. I tracked the problem to a pcb connector that 
just needed a little massage. Luckily because removing the PCB is some 
work.
It´s a well constructed synth and I used to think that an EG was an EG 
until I turned on the MOTM-800 the first time. On the paper "just 
another EG" but my compliments to Paul. The 800 is a really good EG. 
On the Korg (and a lot of other synths) you have fast, middle and slow 
(more or less) but the 800 really gives you all the inbetweens.
Well, I´m getting CV and gate from the Korg and I´m about to build in 
some buffers so I get Modwheels and LFO´s out of it too. Hope it´ll 
work some more years, its a nigthmare to track down malfunctioning 
electrolytics and other stuff.

greetings

Gregory

> 
> ** I have a Mo/Po, too. Turned it on the other day for the first 
time in
> months, and it was not tracking in tune. It's been perfect for over 
20
> years, so I was a little bummed. Hopefully it's just a matter of
> calibration, but I'm fearing that caps and/or some CMOS chips are 
due for
> replacement. Not rocket science but it will be hours of work. :-/
>

You are correct in your understanding of what through zero means.
It is my understanding that through zero modulation can be achieved with
a triangle core VCO, but not with a sawtooth core VCO.  But the VCO must
be designed with this in mind and the design is not trivial.

Paul H.

-----Original Message-----
From: motm@yahoogroups.com [mailto:motm@yahoogroups.com] On Behalf Of
gregorykjar
Sent: Wednesday, December 07, 2005 2:46 PM
To: motm@yahoogroups.com
Subject: [motm] Re: VCO FM question

Hi

Well, I didn´t want to make a complete DX7 replica. You can get a 
long way with just 2 VCO´s, with an EG and a VCA to control the 
feedback/FM. I´ve tried that in Reaktor, but then again thats in the 
virtual world. It would be great with real knobs.

Do you by "through zero" mean that it goes down to zero hertz and 
then through to "negative" (phase reversed?) frequencies? (within 
one cycle)
I realise this is probably not an easy design task. Just wishing :-)

greetings 

Gregory



--- In motm@yahoogroups.com, "Paul Haneberg" <phaneber@o...> wrote:
>
> 
> In order to do DX type FM you need the ability to linearly 
frequency
> modulate a VCO through zero.  While the MOTM-300 is capable of 
linear
> FM, it does not have through zero capability.
> 
> I'm unsure whether or not you need oscillators which reset to zero 
on
> the leading edge of a gate.  This may not be necessary, but I 
assume the
> DX series does reset to zero.
> 
> Even if the MOTM oscillator was capable of meeting the above 
criteria,
> you would need a very large system to replicate the DX7.  Six 
VCOs, Six
> VCAs, Six Envelope Generators at the minimum.
> 
> Personally, I would welcome a new MOTM VCO with these 
capabilities, but
> I haven't heard anyone else except Dave Bradley express the same
> sentiments.
> 
> Paul H.
> 
>   
> 
> 
> -----Original Message-----
> From: motm@yahoogroups.com [mailto:motm@yahoogroups.com] On Behalf 
Of
> gregorykjar
> Sent: Wednesday, December 07, 2005 1:50 PM
> To: motm@yahoogroups.com
> Subject: [motm] VCO FM question
> 
> Hi
> 
> I´m still a bit new to MOTM and dont have any MOTM VCO´s yet. 
(using 
> my old Korg Mono/Poly as main VCO´s) Can you do FM in the "Yamaha 
DX7 
> way", with it? (feeding/modulating it with its own or another 
VCO´s 
> output) Or is this only possible in a virtual digital domaine?
> 
> greetings
> 
> Gregory
> 
> 
> 
> 
> 
> 
>  
> Yahoo! Groups Links
>








 
Yahoo! Groups Links

> You can make FM sounds with MOTM modules, you
> just can't get the precision that you get with a
> digital synth (like DX7) in terms of keeping the
> modulator to carrier ratios precise all the time.

Not to mention that FM synthesis in the Yamaha line of synthesizers is 
really not FM synthesis - it's phase modulation synthesis.

http://en.wikipedia.org/wiki/Frequency_modulation_synthesis

-->Neil

-------------------------------------------------------------------------------
Neil Bradley            "If you owe the bank $100, it's your problem. If you
Synthcom Systems, Inc.   owe them $100mil, it's the bank's problem." - JP Getty

Yes, through-zero FM means a phase reversal when 
you go through 0 Hz. This is another critical 
feature to get that DX sound. I've tried to 
replicate DX patches on my MOTM synth and 
although I can create good FM sounds, I can't get 
them to sound exactly the same as a DX.

>Well, I didn´t want to make a complete DX7 replica. You can get a
>long way with just 2 VCO´s, with an EG and a VCA to control the
>feedback/FM. I´ve tried that in Reaktor, but then again thats in the
>virtual world. It would be great with real knobs.
>
>Do you by "through zero" mean that it goes down to zero hertz and
>then through to "negative" (phase reversed?) frequencies? (within
>one cycle)
>I realise this is probably not an easy design task. Just wishing :-)
>

Talk about timing, this was just announced on the AH list:

http://www.cyndustries.com/

On Dec 7, 2005, at 5:28 PM, Scott Juskiw wrote:

> Yes, through-zero FM means a phase reversal when
>  you go through 0 Hz. This is another critical
>  feature to get that DX sound. I've tried to
>  replicate DX patches on my MOTM synth and
>  although I can create good FM sounds, I can't get
>  them to sound exactly the same as a DX.
>
>  >Well, I didn´t want to make a complete DX7 replica. You can get a
>  >long way with just 2 VCO´s, with an EG and a VCA to control the
>  >feedback/FM. I´ve tried that in Reaktor, but then again thats in the
>  >virtual world. It would be great with real knobs.
>  >
>  >Do you by "through zero" mean that it goes down to zero hertz and
>  >then through to "negative" (phase reversed?) frequencies? (within
>  >one cycle)
>  >I realise this is probably not an easy design task. Just wishing :-)
>  >
>
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