Doepfer

Hi Tony,

> What is the A-117 CV response like? Is it vaguely exponential? 
linear? 
> 
> Is this a Shift register based noise circuit where the CLOCK is 
under VC?

Yes, the A-117 produces a simple shift register sequence, but no, it 
is not under voltage control. Thus there is no 'CV response' to talk 
of. 

With nothing plugged into the 'ext clc' socket, the register is 
clocked by an internal oscillator, which is controlled manually by 
the pot on the front. If you don't want to use this, then you can 
plug an external oscillator in, so if you want voltage control, use a 
VCO - the response then will by whatever the response of the VCO is.

For the internal oscillator, the rate pot is perhaps reverse from 
what you'd expect: low knob settings give a fast clock (max f on mine 
approx, 68kHz); turning clockwise to higher settings slows the clock 
down (min f on mine, approx 90Hz). The pot is actually a log pot 
(taper 'A'), and so the high frequency drops off rapidly from knob  
setting 0 to about setting 2 (where it is approx 3kHz), and then much 
more slowly down to the minimum at setting 10. (I did plot a very 
rough graph, but it doesn't really tell you much, but I could post it 
if you like..)

Tim