Vintage Synth Repair

I've got this olde yamaha cs01 which is functional but in a bad shape
- no case, just bare electronics. It's a wonder that this thing works
at all. I would like to make a new case for it and also seize the
opportunity to make some modifications on it but I need some advice on
what's possible to do and what not, so here's what I wanna do: 

- I want to replace the wave form selector with individual switches so
that I can mix multiple waveforms with each other (saw+tri+pulse and
such) 

- I also want to add another row of switches to individually select
waves to modulate the filter by osc.

- I want to replace the switch for the mod wheel with individual
switches for vibrato and filter modulation and add another one so I
can modulate vca as well and one to bypass LFO modulation.

- I would like to add ADSR controls for OSC and VCA and a switch for
each and VCF to bypass either of these.

- I want to add controls to shape my own waveforms (kinda like on the
Roland sh3a.

- a input for VCF and OSC would be cool, if that works at all (audio 2
OSC that is) and some patch points would be awesome so that I can do
stuff like syncing vcf to pwm and such.

- Also I need to get the LFO to modulate much deeper and faster/slower.

Lotsa plans, eh? Well let me know what can be done and some
examples/instructions for already accomplished mods would be veeery
helpful and time saving.

Yes, interesting project, but I'm not sure CS01 is the best candidate for 
such a customization. I don't have the schematics, but I opened mine a 
couple of times for cleanup and I think most of the electronics has been 
packed in a custom made chip.
However, I'd be very curious to see how this micro-synth could be 
customized.
If I remember well, the model II is very close to the original (the one I 
have) except for the Resonance which is a slider instead of a switch. Is the 
filter capable to self-oscillate on this model ? And what is the value for 
this slider ?

Fran\ufffdois


>From: "P........" <phd76er@...>
>Reply-To: vintagesynthrepair@yahoogroups.com
>To: vintagesynthrepair@yahoogroups.com
>Subject: [vintagesynthrepair] Yamaha CS01II mods questions
>Date: Sat, 28 Oct 2006 01:52:49 -0000
>
>I've got this olde yamaha cs01 which is functional but in a bad shape
>- no case, just bare electronics. It's a wonder that this thing works
>at all. I would like to make a new case for it and also seize the
>opportunity to make some modifications on it but I need some advice on
>what's possible to do and what not, so here's what I wanna do:
>
>- I want to replace the wave form selector with individual switches so
>that I can mix multiple waveforms with each other (saw+tri+pulse and
>such)
>
>- I also want to add another row of switches to individually select
>waves to modulate the filter by osc.
>
>- I want to replace the switch for the mod wheel with individual
>switches for vibrato and filter modulation and add another one so I
>can modulate vca as well and one to bypass LFO modulation.
>
>- I would like to add ADSR controls for OSC and VCA and a switch for
>each and VCF to bypass either of these.
>
>- I want to add controls to shape my own waveforms (kinda like on the
>Roland sh3a.
>
>- a input for VCF and OSC would be cool, if that works at all (audio 2
>OSC that is) and some patch points would be awesome so that I can do
>stuff like syncing vcf to pwm and such.
>
>- Also I need to get the LFO to modulate much deeper and faster/slower.
>
>Lotsa plans, eh? Well let me know what can be done and some
>examples/instructions for already accomplished mods would be veeery
>helpful and time saving.
>
>
>
>

_________________________________________________________________
Voyez vos amis en faisant un appel vid\ufffdo dans Windows Live Messenger 
http://imagine-msn.com/messenger/launch80/default.aspx?locale=fr-ca

What I did is to mess with the 2 pots for the filter adjustments
(cleerly labelled on the board - thanx, Yamaha! :)) and now it screams
alot! I came to the conclusion that most of my mods ideas might not be
able to accomplish but I still want to try as much as is possible. I
still wonder if I sould somehow put a switch btw. the OSC and VCF
signal path so that I can let the OSC's waveforms modulate the VCF.
Wonder how that might sound. Also I still would like to know where I
could put some patch points on that thing. A individual ADSR for the
VCA would be awesome too.  

--- In vintagesynthrepair@yahoogroups.com, "francois basquin"
<babouche369@...> wrote:
>
> Yes, interesting project, but I'm not sure CS01 is the best
candidate for 
> such a customization. I don't have the schematics, but I opened mine a 
> couple of times for cleanup and I think most of the electronics has
been 
> packed in a custom made chip.
> However, I'd be very curious to see how this micro-synth could be 
> customized.
> If I remember well, the model II is very close to the original (the
one I 
> have) except for the Resonance which is a slider instead of a
switch. Is the 
> filter capable to self-oscillate on this model ? And what is the
value for 

> this slider ?
> 
> François
> 
> 
> >From: "P........" <phd76er@...>
> >Reply-To: vintagesynthrepair@yahoogroups.com
> >To: vintagesynthrepair@yahoogroups.com
> >Subject: [vintagesynthrepair] Yamaha CS01II mods questions
> >Date: Sat, 28 Oct 2006 01:52:49 -0000
> >
> >I've got this olde yamaha cs01 which is functional but in a bad shape
> >- no case, just bare electronics. It's a wonder that this thing works
> >at all. I would like to make a new case for it and also seize the
> >opportunity to make some modifications on it but I need some advice on
> >what's possible to do and what not, so here's what I wanna do:
> >
> >- I want to replace the wave form selector with individual switches so
> >that I can mix multiple waveforms with each other (saw+tri+pulse and
> >such)
> >
> >- I also want to add another row of switches to individually select
> >waves to modulate the filter by osc.
> >
> >- I want to replace the switch for the mod wheel with individual
> >switches for vibrato and filter modulation and add another one so I
> >can modulate vca as well and one to bypass LFO modulation.
> >
> >- I would like to add ADSR controls for OSC and VCA and a switch for
> >each and VCF to bypass either of these.
> >
> >- I want to add controls to shape my own waveforms (kinda like on the
> >Roland sh3a.
> >
> >- a input for VCF and OSC would be cool, if that works at all (audio 2
> >OSC that is) and some patch points would be awesome so that I can do
> >stuff like syncing vcf to pwm and such.
> >
> >- Also I need to get the LFO to modulate much deeper and faster/slower.
> >
> >Lotsa plans, eh? Well let me know what can be done and some
> >examples/instructions for already accomplished mods would be veeery
> >helpful and time saving.
> >
> >
> >
> >
> 
> _________________________________________________________________
> Voyez vos amis en faisant un appel vidèo dans Windows Live Messenger 
> http://imagine-msn.com/messenger/launch80/default.aspx?locale=fr-ca
>

I used to have a CS01 and I deeply regret having let it go. The PWM
Bass is simply awsome. If that really is a Mk2 you've got, then that
is quite a rare beast.

I would midi it up using a Kenton Midi -> CV interface. This would
give you control over the oscillator (=> pitch/LFO) and leave the LFO
for the filter.

Common mod for a Mk1 was to replace the resonance switch with a pot,
giving more control and more extreme resonance. But the Mk2 has this
already.

On 10/28/06, P........ <phd76er@...> wrote:
> I've got this olde yamaha cs01 which is functional but in a bad shape
> - no case, just bare electronics. It's a wonder that this thing works
> at all. I would like to make a new case for it and also seize the
> opportunity to make some modifications on it but I need some advice on
> what's possible to do and what not, so here's what I wanna do:

Yes, they are quite rare. I hardly find the II on ebay. I have already
considered to midify that thing but right now it would bust my budget,
so I would rather like to put some cv/gate inputs on it, if someone
would show me how to do that and then later use a somewhat affordable
midi/cv converter. I kinda hoped to some cheap mods such as putting a
wire here, add a pot there and exchange this or that cap and resistor
to jazz things up. I still want to funk up the LFO. It would be so
nice to have one or two extra controls to get a much steeper, faster,
slower modulation. I just don't know how to approach this. I'm so bad
at reading circuit boards but I managed to do some minor repairs on
another synth though. I still believe it should be possible to let the
vco modulate vcf by bridging their paths with a wire somehow.  
--- In vintagesynthrepair@yahoogroups.com, Jez <jezosaurus@...> wrote:

>
> I used to have a CS01 and I deeply regret having let it go. The PWM
> Bass is simply awsome. If that really is a Mk2 you've got, then that
> is quite a rare beast.
> 
> I would midi it up using a Kenton Midi -> CV interface. This would
> give you control over the oscillator (=> pitch/LFO) and leave the LFO
> for the filter.
> 
> Common mod for a Mk1 was to replace the resonance switch with a pot,
> giving more control and more extreme resonance. But the Mk2 has this
> already.
> 
> On 10/28/06, P........ <phd76er@...> wrote:
> > I've got this olde yamaha cs01 which is functional but in a bad shape
> > - no case, just bare electronics. It's a wonder that this thing works
> > at all. I would like to make a new case for it and also seize the
> > opportunity to make some modifications on it but I need some advice on
> > what's possible to do and what not, so here's what I wanna do:
>