Powersound Overdriver Colorsound Help


Ok thanks. I guess I’m having a hard time understanding the schematic and which component goes into the next. Q2 collector is loud, R3 is loud, but C5 is quiet. It looks like C5 is next in the path before going into the eq section. I reflowed the solder on C5 but didn’t fix the problem. I’ll keep looking.



Well-known member
You're doing the right thing

What I normally do is print off the schematic as you have and use my probing in combination with continuity checking so I know what side of the component I'm probing e.g. C1 I'd continuity check which side is connected to in, probe it and mark with a tick on the schematic if it's ok then do the R5 side and so on marking as I go with ticks for ok and Xs for dodgy

I'll also often note the voltages on the schematic what they should be if I know and what they actually are

Basically giving you a visual of where your likely problems are

With this you do have more than one path going into the eq you can see where traces join with the dots letting you know its connected it's a baxandall set up boosting and cutting your bass and treble frequencies through Q3 I think obviously depending on the pot positions

So you will hear differences as you have at the transistor outputs depending on the pot rotation e.g. gain cranked more distortion bass CCW less low end etc

So once you find a problem ie something with little volume go back and try to pinpoint where it's lost and review your findings we know for example Q1 C voltage is more what you'd expect at 9v as @Coda said and youve got 17.7v going into R2 so you'd expect double what you're getting there

Did you ever just lift the R2 leg that connects to Q1 C out to see what voltage you got on it

Debugging although it can be a PITA and you just want to get the %^&*$# thing going does teach you a lot if you're more of a layman like me and can actually be enjoyable when you get those eureka moments where you go sh*t that's loud oh that must be an amplification stage.....I've learnt something......who's a clever boy then!

Me, that's who gimme a $%@^&^× biscuit
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