Doepfer

Thanks, Timothy. I will try those values. I also appreciate that you 
explained the math behind your conclusions.

Can you suggest the best way to cut the PCB tracks? (I've done this 
before, but never on purpose.) Is an exacto knife a good idea?    

--- In Doepfer_a100@yahoogroups.com, "Tim Stinchcombe" 
<timothy@t...> wrote:
> > While we're at it, connecting +5v. to the CV2 switched input 
would 
> > make the CV2 knob a wide range tuning knob whenever it is not 
being 
> > used as a CV attenuator.  Zeroing the CV2 knob and centering the 
> > fine tuning control would give the nominal pitch.  I think I'll 
try 
> > this on mine. Does anybody have any ideas of what would be the 
> > optimal resistor values to use to get a reliable 5v. from the 
12v. 
> > supply without loading it too much?    
> 
> If you're just thinking of adding a resistor in series with the 
50k 
> pot, then it will need to be 70kohm, so 12*50/(50+70)=5V with the 
pot 
> at max. Using a 68k resistor will give just a little more than 5V, 
> and its not too expensive current wise, at just 0.1mA (=12/
> (50k+70k)). If you want to arrange it so that it is switched out 
when 
> a patch cord is inserted, the hardest part will be cutting the 
track 
> in two places underneath the socket, which obviously requires 
> removing it (it would be easiest to cut the old one out, desolder 
the 
> remains of the pins, cut tracks, add resistor plus one wire, 
solder 
> in new socket). There are several convenient places to hook-up to 
the 
> 12V rail.
> 
> Tim