[sdiy] CV inputs with bipolar "amount" knobs

[David G. Dixon]

> If it's a DC thing: as I understand it the only problem is, the null
> point is not exactly in the middle of the pot travel. Crude way to
> take care of this: mount the knob on the pot shaft so that the
> marking on the knob is in middle position at the null point.

I believe Harry was talking about centre-detent pots, in which case you
can't really choose the centre independently.  However, if you use 1%
resistors and a decent opamp, I can't imagine this should be a problem.  I
mean, after all, if you need absolutely zero CV to your circuit, unplug the
damn patch cord!  If that's not good enough for you, then a 1k trimmer off
one end of the pot will do the job; which end depends on where the "true
centre" is relative to the detent.