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Re:Jam Man Noise
>in the meantime I am excited and having fun using my Jam Man, but I have
>noticed something that worries me-
>I noticed some static noise every time a loop began
This is the answer I got from Bob Sellon when I reported a similar problem
my Jam Man, I hope it helps to understand...
" There are two possible causes for the noise I can think of; one you
can fix the other you can't.
When Jamman is slaved to an external MIDI clock it determines the
end of the loop by itself based on the tempo of the clock and the
number of beats selected on the front panel. If the operator tries to
the loop manually, the resulting loop will very likely be shorter
than it should be. When the loop is too short, Jamman restarts the
loop twice: once when the end of the loop (time) is detected and
once when the correct number of MIDI clocks has come in. The
solution is to let Jamman close the loop by itself (DON'T tap a
second time). This will get the loops size to it's best fit.
The second cause is based on the jitter on the incoming MIDI clocks
and the resolution of Jamman itself. At best, Jamman can lock in a
loop size to within half a millisecond (512us). The problem is
that most MIDI clock sources have jitter (timing variations) in the
same neighborhood. After the loop time is locked in, the priority in
to stay in perfect sync with the incoming MIDI clock.
The problem is that the combined half millisecond resolution of Jamman
and the jitter on the incoming clock result in the actual size of
the loop changing very slightly every time through. As the loop
size changes, Jamman either shortens the loop or replays the very
beginning of the loop to compensate resulting in potential clicks and
With the PC itself being slaved the jitter gets worse
and so do the clicks and pops.
As I said, there is currently no work-around for this other than, as
you said, not playing anything at the loop edge. The only other
thing I can suggest (which is equally klugey), is to place
something percussive at the splice point which will tend to mask the
I am looking at the problem, however, and will let you know if I
come up with anything.
If anyone out there has any suggestions on how to deal with this,
I'd love to hear it.
Bob Sellon "