[sdiy] Required sample rate for digital envelopes and LFOs

[Tom Wiltshire]

On 1 Oct 2007, at 21:34, Dave Manley wrote:

> Bruce Duncan wrote:
>
>> No wonder digital envelopes have a reputation for being sluggish.
>> On the other hand you can see the level of resources required for  
>> the 40uS sample rate on the envelope you recently coded for the  
>> Modcan Quad EG.
>> A dspPIC uC running at 15MIPs written entirely in assembler with  
>> 12bit output and quad serial DAC
>> On a synth like the Matrix 12 it would have cost 4 times as much  
>> to maintain that level of speed and the power supply requirements  
>> would
>> have been enormous. Never mind the fact that the cost of  
>> equivalent components in the 80s would have been very high if  
>> available at all.
>
> As another point of reference it would be interesting if someone  
> could stick a scope on a P'08.  Per every two voices there is a  
> dsPIC and serial dac that generates 18 control voltages.

Ooh, yeah! I'd be fascinated to hear the result of that experiment!

I've been thinking about a similar scheme myself, so I'd love to know  
more about it.

T.