“The Funk-A-Duck is an envelope control filter which can be used to
produce a wide range of “synthetic” analog-ish sounds. The input causes a
control signal to be generated, which goes up and down as the input
signal loudness contour goes up and down. This in turn sweeps the filter
frequency back and forth.“
the input sensitivity, has major effect on intensity of effect as well
as overall loudness. Important to set this so that when bypassing, the
levels are about the same.
filter. Can be turned up to actually resonate, either continually or
when triggered by peaks of the input signal. This is one thing that
makes the unit rather unique.
filter cutoff frequency. It has a very wide range, so it is possible to
have it set so NOTHING at all comes through. Also, when any of the other
knobs (input, res, envelope, speed) are adjusted, the resonance freq
moves, and needs retweaking.
of the envelope. When fully anticlockwise, the speed is FASTEST.
Recommend using in this position, at least until one is familiar with
the unit.
Original FSB thread and schematic are available here.
I’ve used an LM13700 instead of 2 LM3080.
Drawing it was quite complicated and it came out quite large.
Always double check the schematic before building an unverified layout.
(You may be able to use an LT1054 based voltage doubler but I’m not sure about noise level)
Special thanks go to Digi2t (Dino T.) for drawing this and many other schematics we’ve been using on this blog.
Here’s his video:
