Doepfer

You find my comments written inline.

Best wishes
Dieter Doepfer

> @dieter: overdriving the OTA (what on earth is that?)

an OTA (operational transconductance amplifier) is similar to an operational
amplifier (I hope you know this circuit) but with current in/out (instead of
voltage in/out) and variable current amplification (so called
"transconductance"). OTAs are used in many voltage controlled applications
like filters or VCAs.

> sounds like what i've been trying to do since my post, i.e. clip the
envelope. although
> putting it through the extreme filter produced an in interesting
> envelope in its own right, this wasn't exactly the yoke of the egg.
> the filter is dc coupled or something ?

yes and no: the input is DC coupled, but the output is AC coupled because of
the DC offset of the filter output.

> anyway, is there a module that would serve as a cv compressor ?

a log->lin converter could do this job. Such a module would be no problem
(very similar to the exponential converters in the VCOs, VCFs and VCAs) but
so far nobody asked for such a module.

> just out of curiosity, if someone has time: is the slew limiter not
> much more linear ?

The slew limiter is nothing but a variable resistor and a capacitor followed
by a buffer. Consequently the charge/discharge behaviour of the slew limiter
is exponential too. Only the voltage controlled version of the slew limiter
(A-171) with an OTA could be modified by overdriving/clipping the OTA in the
same way as the VCADSR A-141.