Vintage Synth Repair

Thanks , I tried the VCA DC Offset , it does help a bit .
For it to really help I need to turn it all the way up.
Its good to know that the hi pitch sound is there without any presets , that one was driving me nuts .

Not sure what to do next , the power supply seems clean?
I´m recapping it anyways .

Arnar




----- Original Message -----
Frá: "z3sound" <z3sound@...>
Til: vintagesynthrepair@yahoogroups.com
Sent: Miðvikudagur, 30. Nóvember, 2011 19:23:03
Efni: [vintagesynthrepair] Re: Hi pitched squeal in Sh 2000








tonight i have taken out my own Sh 2000 to take some measurement to try to help you find your noise problem ...but surprise with all preset off i got the same noise and in high pitch tone (in pitch with the keyboard),it is like the top oscillator VCO bleeding though the the supply. but when i hit a preset tab everything sound ok without any noise , and i thing it is perfectly normal to hear the noise when no preset is activated . i have try to undo some of the adjustment on the VCF/VCA board, and by having a wrong calibration of the VCA DC balance VR 205 i been able to recreate your kind of problem..noise and high pitch on top of preset sound ...you may try this 
http://i1211.photobucket.com/albums/cc433/z3sound/Sh2000.jpg 

--- In vintagesynthrepair@yahoogroups.com , Scott Nordlund <gsn10@...> wrote: 
> 
> 
> >I'm having problems with an SH 2000 , it has this hi pitch squeal whenever I play a note. 
> 
> >It's in pitch so it's not some random noise. 
> 
> >It's still there when I turn of all presets ? 
> 
> The sawtooth wave is made by mixing octave divided square waves. Maybe one of the higher octaves is coming through when it shouldn't. 
>