[sdiy] Additive/Subtractive synthesis?

[John L Marshall]

All digital?

How about Starting with a single oscillator in the MHz.

Use the keyboard to divide by "n" to derive twelveth root of two octave of
frequencies. Browse the web for top octave generators (TOG). It would be
simplest to make this monophonic.

Further divide to produce "Walsh" values. For school purposes 16 Walsh
coefficients would make the point; a few dividers and XOR gates. Browse the
web for Walsh Functions. There are a few synth-DIYers that have Walsh
information on their web sites.

Modulate the Walsh values to produce timbre changes, envelopes etc.

You could do all this in a couple of weeks.

Take care,
John
www.sound-photo.com
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----- Original Message -----
From: "Ishaan Dalal" <izx at xizx.net>
To: "Neil Johnson" <nej22 at hermes.cam.ac.uk>
Cc: <synth-diy at dropmix.xs4all.nl>
Sent: Monday, April 21, 2003 7:55 AM
Subject: Re: [sdiy] Additive/Subtractive synthesis?


<SNIP>
>
> Actually this is supposed to be a "Digital Logic Design" project, but I've
> managed to keep the instructor placated with stuff like PCM sampling
> (drums/cymbals and a 30-second sequencer). Wouldn't want to make it "too
> analog", at least I can claim the one oscillator/note as a "digital tone
> generator" :-)
>
>
> Precisely, a "piano" clone with a rudimentary ADSR and a somewhat variable
> VCF is more than enough work for something due in two weeks time! :-)
>
> Cheers, and thanks for the advice,
> Ishaan
>