Vintage Synth Repair

Check for cold solder on the .022mfd polystyrene caps (clear axial looking caps) that are at the left side of each voice board.  I had voices that wouldn't tune and I just put new caps in there.  Problem hasn't come back.  If you put new ones in, even though polystyrene caps are bipolar they have a side that grounds better where the foil seam is.  Sometimes they aren't marked, but sometimes they are.

Good luck
Greg

--- In vintagesynthrepair@yahoogroups.com, "Damir" <roginator1@...> wrote:
>
> Hi guys and first of all happy easter!!!
> 
> I have some free time finally so decided to check OB8 ...
> It had few problems but ... 
> 
> found dead TL081, CA3080 ... kinda regular problems that i fixed easy by replacing ics
> 
> Next is 2 voices that wont go in tune!!
> 
> so Voice 6 //// VCO 2 is going crazy //// tried with another CEM 3340 ... same thing
> 
> VCO 1 and VCO 2 are getting same KEYCV.. VCO 1 track perfect ... VCO 2 is kinda playing what he wants !!
> .. so .. voltages on VCO 2 are ok ... +/-5 and +/-15
> IC 3340 is fully functional one
> 
> KEYCV is from same source to VCO 1 and VCO 2...
> 
> Any idea???
> 
> Thanx
> 
> Damir
>