Comments on trimmers and circuit design

[Synthfool at aol.com]

In a message dated 7/10/97 6:27:12 AM, you wrote:

>Saul Stokes wrote:
>> 
>> A few weeks ago I built a ring modulator from a Serge schem. Once again I
>> came across something that always seems to boggle me about the goal of the
>> circuit designer. It's weird that so much effort is put into a mathmatical
>> solution instead of a musical solution.  What I'm trying to say is that
>> for the most part, many of the trimmer pots within many of the circuits
>> I've build have just as interesting or more interesting sound control than
>> some of the front panel pots.  Take this Serge ring modulator for example.
>> 3 of the trimmers have such a profound control over the waveshape that I
>> couldn't imaging not sending them to pots on the front panel.  The actual
>> schem shows that the final panel has no pots, only two jacks in and two
>> jacks out. What's happening here is that the trimmers are only there to
>> find the correct solution to the circuit, not aid in sound design.  This
>> is too bad. This isn't the first time I've came across this. I would say
>> that 15 of the 100 or so pots on my first modular were suppose to be just
>> trimmers. I'm sure a lot of you have found the same thing and I've read
>> about musicians who open up their synths to tweek the trimmers. Is this
>> just a matter of personal taste?  I'm interested if some designers use
>> trimmers as sound designing tools when they hear how interesting they are.
>> 
>> saul stokes

Personally, I like modulars to be as precise as possible. 

I CAN see your point , but many of us approach synthesis from the theory and
scientific aspect though. For a modular programmer, the understanding of each
module's theoretical purpose is a strength in knowing how to achieve the
sounds one wants. 

For example- If I was to tweek, say an envelope generator's DC offset trimmer
during a patch, yes I could possibly get an interesting alteration to my
sound. However, trim adjustments are often VERY fine adjustments. If that env
gen trim was externalized, I would have a poor envelope generator for many
other purposes and it would require a recalibration for it's "theoretical"
use.

There is an old adage that comes into play when things like this are
externalized-
 "Anything you CAN control, you HAVE to control".

That is, if you want it to be a "proper" module, you have to put it back to
the "proper" settings and this is not always easy without time and test gear.

In a modular setup with modules that are made to be very precise (and Serge
is a great example), understanding what is happening and how to patch what
you desire will usually obliviate the need to mess with internal trimmers in
the first place, IMHO. 

In a non-modular synth though.,, MANY interesting things can be done by
changing trim settings, cap and resistor values and adding signal and
modulation paths that are normally unavailable. If you don't mind mod'ing
your own gear, you can get many unique sounds out of "standard" gear.

K