[sdiy] polyphonic synthesis

[harry]

Hi Seb:  (inline)

Seb Carr wrote:

> I recently became interested in the idea of building analogue synths, but
> through my research on the internet, all kits, modules and schematics are
> for monophonic synths.
>     whilst i know monophonic synths have a unigue sound and can be played
> differently to  polyphonic synths, i am still more interested in building a
> poly synth,
>     But, i understand that poly synths are far more complex.  Would i be
> correct in saying that a poly synths needs  ( at least ) 1 VCO per note of
> polyphony?

Yes!

> I read that you would also need a VCF and a VCA for each note,

Yes!

>
> but surely the synth could be simplified so as the individual oscillatos wer
> combined and then put through a single VCF and VCA?

That would be a Korg MonoPoly or similar.

Actually most analog synths used a number of identical voices, and a computer
to assign notes to those available voices. MOST poly's work this way.

>
>     So, are poly synths actually pretty much out of reach of the home
> builder?

Depends on your financial and technical status. I'd probably BUY one.

>
> Also does anyone know of any kits or pcb's available for a polysynth? (In an
> ideal world a polyphonic fatman kit or something, with a switchable
> monophonic unison mode).
>     Also, do Oakley synths, or any others have any plans for a poly synth
> module?

Most Polysynths need some special circuits... almost everything needs to be
voltage controlled for them to be practical, including all patching, waveform
select
etc.

H^) harry

>
>
> thanx
>
> Seb Carr