SergeModular

> In looking at the GP-6 (and a GP-8, I think it was, that went on eBay a
> while back) I notice that while many elements are provided, their uses
> aren't as obvious as a modular, with which we are all familiar. We all

know

> what a VCO does, but maybe not why it does it. It would seem that the

GP-10S

> is capable of _being_ a VCO, as long as you know the why. It's also

capable

> of being many other things, as long as you know the processes that are
> involved in creating those things. That being the case, I would think
> something like this could only be good, as long as you took the time to
> learn what was possible.
>

It would be nearly impossible to make a VCO or VCF out of the GP-6 or
GP-10S. There are no Operational Transcondunctance Amplifiers, which form
the basis of those circuits. You could make a linear VCA using the
multipliers. Let's see if I can clear up some of the analog computer
nomenclature, as best I understand it.

GP-10S
4 ea. Summer-Integrator Amplifiers = One pole low pass filters, however,
these are more complex as it is possible to switch the input to the
integrator. There also seems to be a switch controlled hold function, or
sample & hold, but this is not clear. So it seems to be a combination
analog switch, one pole filter and sample and hold.
4 ea. Summer-High Gain Operational Amplifiers = Simple mixing amps. It's
not clear if these have a built in feedback resistor, if not then they could
be used as inverting comparators also.
8 ea. Coefficient Potentiometers = Pots configured as voltage dividers, one
leg is tied to ground
4 ea. Initial Condition Potentiometers = Pots tied to + or - DC bias source
for DC biasing a node
8 ea. General Purpose Trunk Lines = I''m guessing that these are multiples
1 ea. Precision +/-10V Reference = self explanatory, DC bias source

Unfortunately, the 2 ea. multipliers on the front panel seem to be an
option. These are ring modulators.

So what could you use it for?

Mixer
Potentiometer controlled filter bank (4 poles)
Potentiometer controlled state variable filter
Potentiometer controlled oscillator
Ring Modulator (with multiplier option)
Linear VCA (with multiplier option)

Not too exciting, huh? But here's some other things I _think_ you could do
with it.

Nonlinear filter/waveshaper
Multisegment envelope generator
Nonlinear control voltage processor
Complex control voltage generator
Multisegment waveform oscillator
Nonstandard filter with voltage controlled resonance (with optional
multiplier)

If you throw in the banana plug modules, then a lot more possibilities are
given. You just have to acquire a new way of thinking, just like when you
first touched a Serge Modular.

John Loffink
microtonal@...