[sdiy] Minimum SNR for quality analog music synthesis?

[Richard Wentk]

At 19:01 06/12/2005, Aaron Lanterman wrote:

>I'm on a couple of PhD proposal committees related to field-programmable 
>analog arrays. I've poking around and peeking and pushing for musical 
>applications.
>
>The devices they're working on are low voltage - 3.3 volts, or even less 
>(they're designed for power power applications). I've been asking about SNR...
>
>When they ask me what SNR, say, their filters or amplifiers should have to 
>be good for music, what numbers should I tell them?

The answer is 'It depends'. There are big differences between hifi, studio 
equipment, and analogue synthesis. The latter is least demanding, and you 
can get down to about 60dB SNR before the sound really starts to fall 
apart. 70dB would be more reasonable and 80dB or better would be doing 
well. I'd guess a lot of 'classic' designs actually do quite a bit worse 
than 60dB once you include all the CV breakthrough and crosstalk and other 
figures.

For audiophile or professional equipment anything less than 100dB would be 
bad. High end pro gear manages up to 110dB or so.

Even with +/- 15V rails, you really don't want to think about how small 
that makes the smallest signal. ;-)

Richard