[sdiy] low voltage filters

[Mattias Rickardsson]

Tom Wiltshire wrote:
> If not the LM13700, then I know the THAT2162 can run at 5V (ok, +/-2.5V). That'd make a good SVF.

Tom Bugs wrote:
> A few months ago I used the V2164 for a StateVariable VCF (and VCO from same
> chip) running from a pair of 3.6V Li-Ion batteries.
> Things worked very much along the lines of similar designs on +/-15V though
> with obvious scaling differences etc.
> Interesting that the ssm2164 datasheet gives a minimum +/-4V

Declare Update wrote:
> Just following up on this discussion! LM13700 SVF, very similar design to Electronotes, Oberheim, Thomas Henry, etc, works on a single supply down to 3.3V. Lower even, but I didn't bother checking past 2.7ish. Very happy :)

If an OTA or a VCA is run on lower supply voltages, will their noise
or headroom get worse or do they keep their function at a fraction of
the power draw?

The OP-amps used in such a low-supply filter will obviously have a
lower headroom (or signal level), increasing the noise in the filter
circuit. But I'm curious how our current-in, current-out components
work in this regard - and also OTAs.

/mr