I finished mine today!
http://pugix.com/synth/cgs-dual-cmos-filters/
I have a few questions about the CV range. First, I followed Ken's
wiring diagram, which runs the FREQ pot between ground and +15V. During
my initial check of the module, it sounded thin and didn't go into low
frequencies. After I patched a +/-5V LFO to the CV input, it would go
down low with a negative voltage input. So it seems to me that the FREQ
pot should be connected to -15V, not ground. This is more of an
observation than a question. The question is what input resistor to use
with it. The 100K value seems too small. I'm going to change this to 270K.
The second, related, question is: How should the trim pot be tuned? It
sets the CV range. I'll probably set it to a sensitivity I like, but I
was wondering if it should be calibrated to 1V/octave.
Thanks,
Richard Brewster
http://pugix.com/synth/cgs-dual-cmos-filters/
I have a few questions about the CV range. First, I followed Ken's
wiring diagram, which runs the FREQ pot between ground and +15V. During
my initial check of the module, it sounded thin and didn't go into low
frequencies. After I patched a +/-5V LFO to the CV input, it would go
down low with a negative voltage input. So it seems to me that the FREQ
pot should be connected to -15V, not ground. This is more of an
observation than a question. The question is what input resistor to use
with it. The 100K value seems too small. I'm going to change this to 270K.
The second, related, question is: How should the trim pot be tuned? It
sets the CV range. I'll probably set it to a sensitivity I like, but I
was wondering if it should be calibrated to 1V/octave.
Thanks,
Richard Brewster