LVM, was Re: [sdiy] PIC Quantizer project

[Grant Richter]

Comments inline

> Seems like a good discussion to have. I don't think it would take a
> huge effort to design a 5V synth as compared to one using "standard"
> levels. One hard part is deciding how to do everything with 0 to 5V.
> How do you handle bi-polar signals? Use +/-2.5V and shift it to 0-5 as
> needed (like, where it meets a digipot)? But if you're going to do all
> that level shifting, maybe you don't save much. We need to examine all
> the voltage levels used in a synth. As others have said, filters don't
> use full-scale signals internally, anyway!

That is the Serge scheme. Control is 0 to 5 volts and audio is +/- 2.5
volts. You still use 1 volt per octave with a 5 octave range.
> 
> 
>> <blasphemy>
>> switching to 0.5V per octave instead of the 'traditional' 1V per
> octave.
>> Then we can still get a full 10 octaves out of the CV range.
>> </blasphemy>
> 

The Synthi and Putney use 0.325 volts per octave (IIRC) in the patch bay.
All the signals are bipolar +/- 2 volts including the envelope generator.

It works OK, but has more hiss than higher voltage systems like ARP.