Vintage Synth Repair

Follow the S&H signal. Even though it usually are opamps and 
transistors that fails, it couls also be the simplest things. I once 
tracked the problem of an ARP to a broken standard small cap (not en 
electrolytic cap). It could also be a pull-dow resistor that have 
gotten out of range.


På 3. mai. 2008 kl. 01.46 skrev cockandswan:

> hey guys,
>
>  i've fixed both the modulation inputs for the filter and my noise
>  generator on my arp odyssey mk1 by replacing op amps. it's sample and
>  hold mixer doesn't modulate anything and i'm wondering if anyone has
>  an experience with this part of the synth. i've replaced op amp A2 and
>  the transistor Q3. One thing I haven't replaced is A3 which is a
>  unique part that i couldn't find for under $15! I noticed there was
>  mentioned of "Z3" working with a charge in C7, but i cannot find Z3
>  anywhere.
>
>  do you think there are more op amps that i need to replace that are
>  feeding the signals INTO the S+H mixer or do you think there are op
>  amps that are suppose to be amplifying the output of the S+H... or
>  something else entirely?
>
>  thanks guys!
>  -johnny
>
> 
tw.  :)

"Those great moments come when musicians are playing together..."
(Bob Moog)