[sdiy] Modular patching rules

[John Mahoney]

At 07:44 PM 2/11/2007, Florian E. Teply wrote:
>[snip]
>Umm, maybe I'm a bit off track there, but wouldn't an attenuator break
>the 1V/octave rule? Okay, that may or may not be a real rule, but in my
>opinion it would be quite handy to retain that value wherever possible.
>Would be cool though to hear from someone more experienced than me...
>[snip]

Not that I'm more experienced, but I'll chime in:

VCOs and many VCFs have carefully-adjusted 1V/octave inputs. The 
attenuators for these inputs are trimpots on the circuit boards used 
for calibrating the modules so that they "track" properly.

These VCOs and VCFs will usually have additional inputs that may or 
may not have input attenuators. (Some synths use output attenuators 
more than input attens, and sometimes you need to use additional 
modules to adjust signal levels.) Some VCOs also have linear FM 
inputs, but that's another subject.

Offset adjustments do not affect 1V/octave tracking. The typical 
input offset controls on VCOs are tuning knobs and range switches. 
VCFs usually refer to offset as "frequency".

Hope that helps.
--
john