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Message

Tuning Module, and "Too Much Stability"

2001-11-10 by sucrosemusic@yahoo.com

Ok, reading that post about the synthesizers.com octave switches led 
me to thinking on the 2 hour ride from my home in CT to my playground 
in upstate NY.  Ok, here's section one.  (Excuse my spelling)

The "Oscillator Helper"
Synthesizers.com has one, but your VCOs don't need one in the sense 
that theirs is a "Helper."  I was thinking more of a voltage 
adjustment unit that's precice.  Assuming (and this is a big 
assumption) that your VCOs always respond to one volt by changing one 
octave no matter where you are on the scale, a voltage bias unit 
would be quite cool.  I was thinking a unit with two "selector" 
knobs, one that's maybe -12 to +12 1/2 steps, and another that's -6 
to +2 octaves.  (Possibly change it to -6 +6 half steps and -6 to +6 
in half-octaves.  I like the other idea better.)  Why would you want 
selectors like this when you could just grab the coarse knob?  When 
you grab the coarse knob and set your VCO up an octave, you've got to 
tune it again.  Sure, it's not too terribly annoying to re-tune the 
osc. but I think it'd be nice to have access to a quick tuning 
selector.  Granted it's biased towards western scales, but so is 
Volt/Octave.  Anyway...  Another feature would be some sort of 
detune...  reason for this?  shown below...

Too Much Stability?
   I've always thought that the quirkiness of analog synths is part 
of the charm.  I'm almost wondering if there's a tangible difference 
between a nearly perfect VCO and a Digitally Controlled one.  Don't 
confused DCO with DO, though.  My understanding (which might be 
flawed) is that a DCO is an analog oscillator tightly paired with a 
digital circuit that maintains the tuning of the oscillator, while a 
DO is just a digital oscillator, using a DAC I guess.  So back to the 
point, if these VCOs are so stable, what's the difference between 
using them and using a DCO?  Wouldn't it be more practical (although 
some purists would be mad) to have a modular, voltage controlled 
DCO?  Ahh, there's a problem there, I see, since you couldn't have 
the unit really respond to a CV signal for tuning, since the digital 
circuit wouldn't know where to tune it to be "correct"... although 
you could do it anyway (on the assumption that the Midi->CV converter 
or your CV keyboard is 100% accurate), or just have a MIDI equipped 
DCO.

Anyway, I'm not saying that I prefer DCOs at all.  I just wonder if 
having a super-stable VCO takes a bit of the warmth out of a modular 
synth?  Again, I'm not sure just HOW stable these VCOs are, if they 
vary by +/- .5 hz then that's one thing, but if it's +/- .001 hz it's 
another.  So, if these VCOs are uber-stable, why not add a goofiness 
factor to the unit I made above, controllable with a pot, CV control 
being probably quite useless.

Regardless of the goofiness factor, I think an accurate, selector-
type module to reside next to the VCO would be neat.  It could even 
have two identical sections.  All it would need (for a basic unit) 
would be 4 selectors, 2 CV ins and 2 CV outs.

Ok, that's all for now, feel free to shoot my suggesions to heck, or 
embrace them as if heaven-sent.  Whee.  Time to go to sleep!

-Overand (Sucrose)  www.overand.com

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