[sdiy] 1-pole LPF using a differential integrator?

[Magnus Danielson]

From: Aaron Lanterman <lanterma at ece.gatech.edu>
Subject: Re: [sdiy] 1-pole LPF using a differential integrator?
Date: Thu, 1 May 2008 00:20:42 -0400
Message-ID: <7F46D30B-9738-4C3E-B582-E325344DD84F at ece.gatech.edu>

> 
> On Apr 30, 2008, at 4:00 PM, rdrake wrote:
> 
> > how about that center-tapped pot on the output?  would love to see an alternative way of implementing that...
> 
> What did you have in mind?
> 
> Indeed that is an interesting feature - I don't think I've seen another synth with something like that.
> 
> I recall the Buchla 258 - I think - has some FET based circuitry that lets you crossfade between a sine and a whatever-other-waveform - maybe something like that could be used here to make it voltage controllable.

I think you are after the Buchla 259 here Aaron. Please check the schematics.

The wavefolder to some degree simulates a sweeping lowpass-filter.

The even/odd harmonic balance pot is interesting.

Cheers,
Magnus