X0XB0X VCO Tuning and Clicking problem

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shawnsick
 
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Joined: Sun Mar 09, 2014 5:49 pm

Re: X0XB0X VCO Tuning and Clicking problem

Post by shawnsick »

anyone?

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antto
 
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Re: X0XB0X VCO Tuning and Clicking problem

Post by antto »

i don't know..
if you've spotted a wrong voltage around the mixer/vca - check the surrounding components for proper orientation, proper values
if you have a working x0xb0x - you can use that to compare against (both when measuring as well as just visual)

shawnsick
 
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Joined: Sun Mar 09, 2014 5:49 pm

Re: X0XB0X VCO Tuning and Clicking problem

Post by shawnsick »

I just noticed that I had not hooked up my oscilloscope correctly, I am now noticing that the voltage actually drops whenever I press a note, in slide mode the notes are okay the thumping/clicking only appears on the first note pressed but the thump appears on every note when not in slide mode.

I have tried replacing Q1 Q2 Q3 Q4 and Q31 and Q32 as I read somewhere that unmatched transistors in those places can cause clicking issues when using BA6110 IC but this was not the issue. Also I am not getting any voltage coming through the 1st pin of Q31 yet I should be reading 2,70V (even after changing the transistor) I'm not getting any reading anything on the center pin of Q31 (111mv) nor any other places it's linked to. Also Pin 4 of the BA6110 isn't receiving anything.

I have checked all of the components multiple times, every component is in it's place, correct resistors, capacitors, capacitor polarities, transistors are all correct, IC's, I have triple checked m soldering I have even removed flux on the board just to be safe. I am really puzzled with this thing, any more ideas? Any sort of advice would be appreciated, I have sold my other machines so I cannot compare it to another one.

shawnsick
 
Posts: 18
Joined: Sun Mar 09, 2014 5:49 pm

Re: X0XB0X VCO Tuning and Clicking problem

Post by shawnsick »

Finally tracked down the problem, it was Q39 causing the problem. :D :D :D

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antto
 
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Re: X0XB0X VCO Tuning and Clicking problem

Post by antto »

weird
i've ran my x0x with and without Q39.. and nothing audible changed

oh well, good to hear it works now

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