MOTM-120 Mod suggestion

[John Speth]

> 2) This brings up an interesting point: what differences would
> ANY gate make in this circuit?
> (The MOTM-120 has 2 4-bit counters that are AND'ed together in CROSS mode)

The chances output would be silent or not was just an observation I made
while testing.  I casually reasoned that the AND gate can gate off even if
one input is always changing whereas an XOR won't.

Here's my test conditions: Prophet 5 just sending the A440 tuning signal in
A, Kawai K1 sending some Hammond like sound to B, all divider pots set to
50%, mode set to cross-mod, input pots set to 0.

Here's my test (with AND gate): While pressing one key on the K1, I get the
nice digital ringmod sound.  When I release it, sometimes the output is dead
silent.  I didn't gather statistics about how often but it  was random and
close to 50% (by my memory only) of the time for maybe 10 tries.  Using the
XOR, with the same exact test, I would never get silence.

I'll admit I never rigorously tested nor analyzed this aspect of circuit
performance.  And it's not a complaint since I think the AND gate produces a
much more interesting signal.  I'll have to say I was happily surprised by
the versatility of this module after playing with it for a long time.

John Speth
Object Engineering, Inc
mailto:johns at oei.com