VCA weirdness

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Fiercefish
 

VCA weirdness

Post by Fiercefish »

Does anyone have a problem with the VCA not shutting off notes all the time? Mine has worked perfectly, then occasionally the notes still sound after the VCA should have silenced the VCO, giving a faint drone until a new note is triggered. Accent seems to get rid of it MOST of the time but not always, but the weird thing is sometimes it is ok. Its kind of hard to troubleshoot as it is an intermittent problem. So whatcha think? Firmware bug or hardware fault?

(BTW I have updated the firmware a couple of times to see if it was a flash problem)

Cheers

FF

Guest
 

Post by Guest »

its most likely a flaky connection somewhere in
the gate section
rehit your solder joints and see if it helps

Fiercefish
 

Post by Fiercefish »

I went over it again (re-soldered) and it seemed fixed for a while, but it has started droning again :cry:

I had D37 in backwards when I first assembled it, but fixed that, do you reckon a component has been damaged from this which could be causing this VCA problem?

Any input much appreciated its driving me nuts!

FF

Guest
 

Post by Guest »

i doubt the backwards d37 had any effect

next time it starts droning
measure the following voltages with respect to ground
gate out
junction of r151 and q38

if either of these are high
the gate section is faulty

if neither is high there is an open somewhere
in q1 through q4 or q31 or the ba6110

Fiercefish
 

Post by Fiercefish »

I should also add that the droning is about 1/3rd the volume of a normal note, I will check the areas you suggets though :)

asmodee
 
Posts: 19
Joined: Tue Feb 14, 2006 9:25 pm

Post by asmodee »

What is "gate out"? D35/D36?

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