30 years later...

Kimmo Koli kimmo at clara.hut.fi
Thu Oct 31 09:12:09 CET 1996

On Wed, 30 Oct 1996, DJMaytag wrote:

> ok. analog synths have been around for 30+ years (and i'm sure that regular
> function generators have been around longer), but why is it that we're still
> stuck with the same 4 waveforms (saw, tri, sine, pulse) from day one? isn't
> there anything else that can be done to get some 'alternative waveforms'
> (other than using ADSR and LFO modulation)? i mean, i'd much rather use the
> 4 waves than sampled waves, but isn't there anything that's been done to get
> some more timbral variation lately?

Well, I'm doing just that. Unfortunately I'been too busy a work so that the
circuits have not been built yet (=only simulations so far).

What I'm going to do:
 A fully VC controlled waveform set in a VCO
 1) From triangle to saw
    something like the Casio phase distortion with a thick analog VCO.
 2) Double Saw: one shorter one longer
    a slow shift to an octave higher tone.
 3) Normal PWM
 4) Double Square
    like double saw...

Why it has not been done yet ?
 It is not that easy ! It was about the third in fourth approach to this
 problem that probably will work.

How complex:
 2 CA3096 transistor arrays
 7 opamps
 CMOS switches and CMOS inverters 

And someting else:
 A chaotic sub-oscillator for the VCO.
 Two timbre pots and an amplitude envelope.
When these circuits work, I'll put it on my web page.
Most likely the chaotic sub-osc comes first (it's so simple), hopefully 
within a month.

Hope this timetable isn't as reliable as with the Paia MIDI2CV8,
  Kimmo Koli      			     kimmo at ecdl.hut.fi 
  Helsinki University of Technology          http://www.ecdl.hut.fi/~kimmo
  Electronic Circuit Design Laboratory
  Otakaari 5 A 
  FIN-02150 Espoo     			     Tel:  +358 0 451 2273
  Finland      				     Fax:  +358 0 451 2269

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