[sdiy] Additive/Subtractive synthesis?

[Ishaan Dalal]

You mean use a divide-by-n IC, for each note....? As I was saying to Neil,
the only available ones that can do custom (not 2^n)  of frequencies would
be skew the allotted budget we have to keep to. If it's a custom octave
generator IC, my instructor probably wouldn't allow it...it has to look as
if the basics are our work...doing an excellent VCA/VCF job on a readymade
tone generator would, IMO, definitely lose us marks. If I were doing this as
a personal project, though.... :-D

Thanks anyways...I have just under two weeks as of this moment to finish the
thing....whatever it finally turns out to be. I'm hooked onto analog (or
pseudo-analog, i.e. using digital stuff to generate, filter, mix) synthesis,
and will definitely be working on some project over the summer that would
involve analaog synthesis.

Cheers,
Ishaan



----- Original Message -----
From: "John L Marshall" <john.l.marshall at gte.net>
To: "Ishaan Dalal" <izx at xizx.net>
Cc: <synth-diy at dropmix.xs4all.nl>
Sent: Monday, April 21, 2003 9:00 PM
Subject: Re: [sdiy] Additive/Subtractive synthesis?


> 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
> --------------------------------------------------------------------------
-
>
> ----- 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
> >
>