In the SUB mode it should not matter what is going to input B at all.
The B input should be ignored. Why would eliminating "clock jitter" on
the B input make any difference? It seems to me this has little to do
with what mode the 120 is in, because in the scenario described there
are inputs on both A and B, and the solution is to modify both comparators.
Paul, what is your take on this modification?
-Richard Brewster
Tom Adam wrote:
>I was surfing the net a bit and stumbled over this link:
>http://www.techman.synth.net/techman_website2_00002e.htm
>copy:
>"When it came to testing this module, I was a little perturbed that it
>didn't work as I expected. in sub mode, turning up each of the four sub
>octave pots produced glitches in the audio if I had signal on both the A
>IN and B IN jacks. This couldn't be right. ... This time I happened to
>put the scope probe on the non-inverting input of the input comparator,
>and lo, the glitching stopped. Aha.. the capacitance of the scope probe
>had stopped the clock jitter. Solution: I happened to have a couple of
>18pF ceramic caps handy, so I put these across the non-inverting input
>and ground (Pins 2 & 1) of both of the 311 comparators. Problem solved.
>The module now appears to work as intended...."
>
>Since I was experiencing the same problem, I tried it out. I needed to
>take apart the whole module to be able to fit the caps, but the result
>is very nice. Now I know what a MOTM-120 should sound like. Very cool!
>
>Cheers,
>Tom
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