Something new(ish)? (Re: 1970's again? (was Re: [sdiy] pro EQs))

[John Loffink]

Look here:

http://www.oldcrows.net/~patchell/synthmodules/shaper.html

and here:

http://www.wavemakers-synth.com/motm/dws.html

for examples of diode waveform shapers.

I find my shaper useful for adding gradual degrees of distortion to
waveforms, or making "composite" tones by modulating with waves from
multiple VCOs or VCFs.

You are correct that these circuits originated with analog computing, yet I
have never seen an implementation in "classic" (i.e., Moog, Buchla, Serge,
Emu, etc.) modular synthesizer format.

John Loffink
The Microtonal Synthesis Web Site
http://www.microtonal-synthesis.com
The Wavemakers Synthesizer Web Site
http://www.wavemakers-synth.com


> -----Original Message-----
> From: owner-synth-diy at dropmix.xs4all.nl [mailto:owner-synth-
> diy at dropmix.xs4all.nl] On Behalf Of Anthony Ankrom
> Sent: Friday, December 31, 2004 8:09 AM
> To: Paul Maddox; Synth-Diy
> Subject: Something new(ish)? (Re: 1970's again? (was Re: [sdiy] pro EQs))
> 
> I have read about something that I don't think anyone's ever applied to
> synth work, but it might be
> interesting.
> 
> Just the other day I stumbled across an old article about "non-linear
> transfer functions". The circuits in the article
> used very large arrays of "forward biased" diodes in the feedback loops of
> op-amps. It said forward biased but
> the diodes were "pointing" the same way as the op-amps so I would think
> this
> would be reversed biased, but hmm
> maybe it was because it was in the inverting input?
> 
> And the arrays seemed to be strings of diodes of varying/increasing length
> in parallel. Like the first was one in
> parallel with a string of two in parallel with a string of three and so on
> -
> with variations on this theme.
> 
> The aim here was some analog computing application, but isn't that what
> analog synths are in a nutshell?
> They're analog number crunchers with audio user interfaces.
> 
>