[sdiy] Required sample rate for digital envelopes and LFOs

[Tom Wiltshire]

Hi All,

With respect to my recent question about the required sample rate for  
digital envelopes and LFOs, I came across the following:

Wolfram Franke, quoted in a review of the Waldorf Pulse, Sound on  
Sound Feb 1996.

(http://www.soundonsound.com/sos/1996_articles/feb96/waldorfpulse.html)

"Digital machines and digitally-controlled analogue synthesizers  
always suffer from one problem: they are slow at processing  
modulation, either digital or analogue. On the Pulse, we developed  
control voltage generators that are really fast. The modulation  
update is 523 times per second, which means that each modulation gets  
updated every 1.9mS. This gives you envelopes with analogue feel and  
digital control."

The same article mentions Tom Oberheim's Marion Prosynth in passing,  
which it says "has an update speed of 16 to 22mS!".

So there you go. 523Hz is 'really fast' according to at least one  
important and influential figure in synthesizer design. The MSR2 and  
Prosynth envelopes are both notoriously lazy, but at a rate of  
50-60Hz, I'm not surprised.

Regards,

Tom