Archive of the former Yahoo!Groups mailing list: MOTM

Larry, I'll throw a quick 2 cents in on a couple of points from your
sequencer questions Email:

Quantizing: usually a separate module, for the reasons you point out. I'm
one of those people (Theremin afficianado, to be sure) always crying for a
quantizer module, but they seem to be fairly rare in the synthesis world.

Number of CVs per stage: I think 3 is a reasonable minumum [and five is too
much because of cost] because of the next point...

Timing: The standard way this happens is this---if you are doing a standard
"Tangerine Dream" kinda thing where all steps are equal duration, you could
use all 3, 4, whatever CVs per stage to control whatever you want (pitch,
filter Fc, &c.). the only way this can happen is that the "A," "B," "C"...
CVs of each stage sum to single "A," "B," "C"... output jacks (otherwise
you have a million jacks and multiples all over the place). But each stage
has its ∗OWN "Gate Out"∗ that goes high while that stage has the ball, so to
speak.

So anyway, for a constant duration per stage, there's usually a simple
internal clock. But you can often break that with a jack to use an external
clock, and the only reason you would want to do that is... voltage control
of duration! If you use a VCO as a clock, you can feed one of the CV ranks
to control that VCO's pitch. So say the "B" output of the sequencer controls
the pitch of the VCO (or VCLFO, &c.). Now the second knob in each stage
controls the duration of its own stage.

# of Steps: As stated above, each stage gets it's own gate out jack. There
is usually also some sort of "Master Reset" input jack that, when tripped
high, restarts the count at "Zero" or stage-1 of the sequencer. So if you
want to have a loop of 17 notes, you could just run a patchcord from the
Gate Out of stage-18 to the Reset In jack, and viola. (It goes without
saying that if the Reset trips on a negative-going slope, you would use the
stage-17 gate... also, related to this discussion of Gates and Resets, there
are sometimes "End" jacks and other niceties to allow you to gang two
sequencers, either in parallel to double the amount of CVs per stage or in
series by cross jacking the End and Reset jacks... I'm kinda blurting this
out and probably making mistakes but I know you can see where I'm going with
this).

Four Cvs per stage makes a nice number because with some decent design, the
sequencer can be used to output CVs A, B, C, &D per stage OR double the
number of stages by putting out A & B on pass-1 and C & D on pass-2. This
still leaves 2 CVs per stage, enough to control stage duration and a single
master pitch.