Vintage Synth Repair

I have posted the service manual on my downloads page at
http://www.paintingwithsound.co.nz/downloads.htm. Look for the section
"Keyboard Control Voltage Memory". Because the note is climbing I
would look at Q6 first as it is probably leaking current into the
sampling cap c13. Regards



--- In vintagesynthrepair@yahoogroups.com, "thirteentech"
<thirteentech@...> wrote:
>
> --- In vintagesynthrepair@yahoogroups.com, "thainmlh" <mike.hunter@>
wrote:
> >
> > Hi, new to the list. I have two questions pertaining to an ARP Axxe
> > 
> > 1) It seems to me that the CV Memory needs alignment or repair. If a
> > note is depressed and released, the pitch slowly climbs. If the key is
> > depressed and held, the pitch remains constant.
> > 
> You can try cleaning the circuit board top and bottom around the CV
memory circuit, from 
> memory it is a very high impedence circuit with a single FET and a
dual FET and discharge 
> capacitor, so if ther is contamination on the board, particularly in
humid weather, there could 
> be leakage. As this is a sample and hold circuit it needs to be leak
free. 
> 
> Otherwise you would be looking at  (depending on which version Axxe
you have) C13, Q5 or 
> Q6.
>