[sdiy] Multiplexed Expo Converter?

[Antti Huovilainen]

On Fri, 31 Jul 2009, Tom Wiltshire wrote:

> What's the fastest pitch modulation? Nyquist demands at least twice that 
> frequency. I'd recommend oversampling by a few times (x4 maybe) just to be 
> sure.

Nyquist criteria assumes good (read: high order) anti-alias filter after 
the hold. You won't have that in any reasonable multiplexed CV system 
because of the huge parts count. 4x oversampling with RC lag filter will 
of course help, but since we're dealing with audio rate modulation, you 
will still get unwanted sidebands due to inadequate bandlimiting.

Antti

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