I'm about to start on a Synthacon filter also, but only one of them.
control.
CV input jack with no pot that makes the filter track at 1V/octave
(approximately--I'm not expecting high precision from this filter), and
another CV input jack with an attenuator. That way the filter can be set up
to follow a keyboard CV with a variable amount of envelope CV be added, both
independently of the nominal setting of the frequency control. Looking at
the schematic I think one could just add another input resistor at the base
of the transistor, but that might make the CV inputs prone to interaction so
adding a simple op-amp CV mixer before the transistor might be a better way
to go.
--Adam
> one question about pots though. i've been searching the archives and iPeering at the schematic, it looks like the 100k pot is the frequency
> can't find an
> answer.. which pot goes where? does 100k
> control freq or resonance?
control.
> one more q, what value pot will be needed to add a CV Amount pot to theI've been pondering similar questions. What I'd like to end up with is one
> freq cutoff
> control , and should it be wired simply in series w the CV input jack?
CV input jack with no pot that makes the filter track at 1V/octave
(approximately--I'm not expecting high precision from this filter), and
another CV input jack with an attenuator. That way the filter can be set up
to follow a keyboard CV with a variable amount of envelope CV be added, both
independently of the nominal setting of the frequency control. Looking at
the schematic I think one could just add another input resistor at the base
of the transistor, but that might make the CV inputs prone to interaction so
adding a simple op-amp CV mixer before the transistor might be a better way
to go.
--Adam