MOTM

This module came up last week.

To those of you trying to create something similar, has anyone looked at the
'reverse engineering' speculation at
http://www.geocities.com/soho/museum/4459/diy/sergewsh.html ? It has scope
traces of the module being put through its paces. It does look like a clever
series of biased full-wave rectifiers.

Again, that's from a printout, so I can't verify from here that it works
(I'm not actually at my PC at the moment...)

>... has anyone looked at the 'reverse engineering' speculation...

And speculation it is. I have the full schematic and it is so simple it
nearly made me cry. Only the lower section has a 3900. The rest of it is
3080s and dual op-amps. The middle section is basically a series of
differential amplifiers with parallel diodes in place of the resistor to
ground. The two inputs of each diff amp are connected together.

I built a clone, and it does indeed sound very good. If a little
unusual.

Regards,

Tony Allgood  Penrith, Cumbria, England

Oakley Modular Synth and TB3030:
www.techrepairs.freeserve.co.uk/projects.htm
My music: www.mp3.com/taklamakan

On Fri, 17 Nov 2000, Tony Allgood wrote:

> 
> I built a clone, and it does indeed sound very good. If a little
> unusual.
> 
Which reminds me of a question that I (and at least one other person)
have:  How do the Serge wave mult., Tony's WaveFolder, and the timbre
modulator circuits in Barry Klein's book compare in audio?

Jeff

In a message dated 11/17/2000 11:27:00 AM, jpont@... writes:

> How do the Serge wave mult., Tony's WaveFolder, and the timbre
>modulator circuits in Barry Klein's book compare in audio?

An initial comparison reveals an important difference: you can buy one of 
Tony's Wavefolder PCBs, if you want a Serge you need to buy about eight other 
modules too (since Rex only sells a panel at a time), and Barry's (from 
Electronotes I believe) isn't for sale anywhere.

JB

>How do the Serge wave mult., Tony's WaveFolder...

Well I have some samples up on my page of my Wavefolder.

If I get sometime I'll try to sort some samples out on the Middle
section of the VCM. It sounds nothing like my WaveFolder... its more
like a badly distorting resonant filter with high Q. With fast AD
envelope feeding the CV, it sounds a bit like a DX-7 doing a slap bass!
Give me a few days to sort something out... got a CD-rw to fix first.
Bloody thing is being ignored by my PC completely, even at start up.

Regards,

Tony Allgood  Penrith, Cumbria, England

Oakley Modular Synth and TB3030:
www.techrepairs.freeserve.co.uk/projects.htm
My music: www.mp3.com/taklamakan

> 
> > How do the Serge wave mult., Tony's WaveFolder, and the timbre
> >modulator circuits in Barry Klein's book compare in audio?
> 
> An initial comparison reveals an important difference: you can buy one of 
> Tony's Wavefolder PCBs, if you want a Serge you need to buy about eight other 
> modules too (since Rex only sells a panel at a time), and Barry's (from 
> Electronotes I believe) isn't for sale anywhere.
> 
I am really after audio examples, for interest, not purchase options.
FWIW, part of the reason I opted for motm was I didn't want to deal with
having to buy an entire Serge panel.  As long as my module assembling
skills (minimal at the moment) result in functional modules and I have
the time, Tony's WaveFolder is on my future diy list.  Barry Klein's book
is still available (I bought a copy about 4 weeks ago) at:
www.xavax.com/bklein/em.htm 

Because I'm a novice at assembling this stuff, reading schematics tells me
very little about how an 'audio module' will sound.  So, I'm just after
some audio 'clips' to get me oriented.

> Well I have some samples up on my page of my Wavefolder.
These I've listened to and found them to be interesting.

>If I get sometime I'll try to sort some samples out on the Middle
>section of the VCM. It sounds nothing like my WaveFolder... its more
>like a badly distorting resonant filter with high Q. With fast AD
>envelope feeding the CV, it sounds a bit like a DX-7 doing a slap bass!

These I would greatly appreciate.  Tony, please take your time (get that
cd-rw running), and as before, I appreciate your willingness to help me
out.


Jeff