Confused with 0TA3080

[Marc Nostromo [M-.-n]]

> if you remove R7, the voltage at pins 2 and 3 of the first ota whould be
> half the supply voltage. if you put R7 beck in circuit, the dc level
> shouldn't change much.

So, If I have R10,R9 connected, I get half voltage. i.e. 2.5v

However as soon as I connect them to the ota, the voltage goes to 3.6.
Pin 2 doesn't really matter. Pin 3 makes the voltage change (R7 is
disconnected). The ota does output about 2.9v no matter what

Maybe


> also check the voltage on the junction of R11.R16, and that this is varying
> somewhere in the range 1V..4V, according to the cutoff.

They vary. Not in that range (it's 0.2 / 2.4)  but they do.

> also check that, when you do this, the voltage across R11 is the same or
> very similar to that across R16, and that these vary in unison as you
> sweep the pot.

They seem to. I guess I'll have to find a small 3080 standalone
circuit to see if it works or not.

Thanks for the suggestions.