troubleshoot VCO: no SAW, only SQUARE
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Re: troubleshoot VCO: no SAW, only SQUARE

by substyler on Fri Mar 11, 2011 3:00 pm

DjunaSaurus wrote:
SubStyler wrote:check the area around C11, C31, C32 (voltages across) Q24, Q25 and the solder joints at S1.
maybe one of your eletcrolytic capacitors is bad or soldered in a wrong direction?
if you try to get saw wave, IC23 is getting hot?


I triple checked and everything is soldered right. But I didn't solder C31 and C32 yet (the manual didn't say so), but that normally shouldn't have any effect on the saw right?

you're right. I did not know how far your build has gone at this time. I had the same problem recently and it was a faulty electrolytic cap... C11 to be exactly.
therefore my thought.
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Re: troubleshoot VCO: no SAW, only SQUARE

by pattern9 on Sat Dec 15, 2012 2:45 am

This is for reference to the future builders.

I had this problem too.

No saw, only square. R105 gave me a loud pop on the headphones.

After completing the VCF i could hear both waves.
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Re: troubleshoot VCO: no SAW, only SQUARE

by monoloco on Thu Apr 04, 2013 5:05 pm

so once again theres a vco completely build
but no saw just a square wave :?
all components triple checked... doesnt feel right to just go on there must be a reason why it doesnt work
any suggestions ??? please!!
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Re: troubleshoot VCO: no SAW, only SQUARE

by antto on Thu Apr 04, 2013 5:29 pm

well, the square wave is made out of the sawtooth, which means it most likely works
i'd suggest continue forward and check the waveforms again later :wink:
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