Re: LVM, was Re: [sdiy] PIC Quantizer project

[Roman]

It's not blasphemy when compared to what I wanted to do.
0.1V per octave
<duck>
Yes, I'm that crazy. But if 20 years ago it was possible to make synths out of 741, why it shouldn't be possible now with opamps  100 times better in DC accuracy which are not so rare and expensive? Even at 0.1V/oct theoreticaly they should be 10 times more acurate than old designs.
5V precision opamps, possibly R-R, supplied from +/-2.5V.
Discrete OTA cell needs only about +1V while on negative side there's -0.6V required for Vbe and some margin for the driving opamp.
Filters can be made out of that, VCAs, envelope cores etc.
And I see no reason why envelopes should be in 0-5V range, not +/-2.5V. Negative envelopes are also usefull.
Transistor ladder may be difficult to fit within 5V, but there are so many other filters to try. Beside that I cannot think of a module that couldn't be done in 5V.
And all that supplied from 1 LiIon cell and DC/DC converter (yes, I know about the switching noise and how bad idea this is)

Roman

---- Wiadomość Oryginalna ----
Od: Tim Parkhurst <tparkhurst at siliconbandwidth.com>
Do: 'xamboldt' <xamboldt at earthlink.net>, 'Synth DIY List' <synth-diy at dropmix.xs4all.nl>
Data: Mon, 15 Nov 2004 12:38:14 -0800
Temat: RE: [sdiy] PIC Quantizer project

>
><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>
>
>Anyway, scaling the CVs from other sources would be easy, but I thought that
>might just be one application of a quantizer chip.
>
>I await your comments, insults, tars and feathers. 
>
>
>Tim (Haven't really thought this through, but I thought I'd talk about it as
>an authority anyway) Servo
>