Vintage Synth Repair

Taking another look using your directions .

Thanks !


----- Original Message -----
Frá: "z3sound" <z3sound@...>
Til: vintagesynthrepair@yahoogroups.com
Sent: Mánudagur, 28. Nóvember, 2011 09:44:31
Efni: [vintagesynthrepair] Re: Hi pitched squeal in Sh 2000








Hi Arnar 
First monitor with the scope the supply +15 and -15 in ac mode to see if any noise from the power supply 
Do you have that fuzzy look directly at the output of the VCO (collector of Q105 or pin 1 of connector)VCO board ?? If not you have to track the signal to see where the noise begin to show ,you can also check the output of the divider board VG-7 check pin 20 .next the output of the VCF (push VCF Man tab ,put the cutoff fully clockwise and the resonance to zero) pin 9 of VCF board. if no fuzzy thing move to the VCA out pin of the same board. Hope will help. If do don't have the schematic I can post it 
Z3 

--- In vintagesynthrepair@yahoogroups.com, "plat@..." <plat@...> wrote: 
> 
> I will check but I don't think its that . 
> Looks fuzzy on the scope , maybe squeal is not the right word ..more like a whine with noise. 
> 
> Thanks! 
> 
> Arnar 
> 
> 
> 
> ----- Original Message ----- 
> Frá: "jammie" jammie.emma@... 
> Til: vintagesynthrepair@yahoogroups.com 
> Sent: Mánudagur, 28. Nóvember, 2011 03:53:15 
> Efni: Re: [vintagesynthrepair] Re: Hi pitched squeal in Sh 2000 
> 
> 
> 
> 
> 
> 
>  
> sounds like filter is set to high resonance as its in pitch and is tracking pitch 
> 
> see if you can adjust the resonance and if it has any effect 
> 
> 
> ----- Original Message ----- 
> From: plat@... 
> To: vintagesynthrepair@yahoogroups.com 
> Sent: Monday, November 28, 2011 11:44 AM 
> Subject: [vintagesynthrepair] Re: Hi pitched squeal in Sh 2000 
> 
> 
> 
> 
> 
> 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 ? 
> 
> PSU is recapped. 
> 
> Any ideas? 
> 
> Thanks 
> Arnar 
> RVK 
> Iceland. 
>