redhothoshi
Registered User
Join date: Jul 2011
10 IQ
#1
Hello, I bought, as the title suggests, an older Classic 50 that's without an effects loop, and find myself wanting to play more with delay and modulation effects, but I'm not really liking the sound out front.

Now, I emailed Peavey and have a schematic for the retrofit board they used to sell and even what the PCB should look like, but I'm a little... well, hesitant to put it together myself. Installing it wouldn't be an issue and I understand how to drain the caps and that I absolutely need to in order to be safe and work inside of the amp.

Now, I guess I'm just looking for some verification. I don't have the means to etch a PCB and I'd really rather not pay for it to be done because I really just need the one board. It should be possible to make a board that compact using perf board, correct? Using a similar layout to the PCB.

Here's the schematic for the board itself.



It should work all the same if I use perfboard as long as all the right connections are made, correct? That feels like a dumb question but I want to be 100% sure before I go adding things to my amp.
redhothoshi
Registered User
Join date: Jul 2011
10 IQ
#2
Bump.
After looking at schematic again, there's no unit marking for the capacitors, all I see is that they're all polarized. Should I assume uF for C50, C53 and C54? C51 and C52 both say .22r10 0m, I'm not too sure what exactly that means. After googling I found a 22r103, which is an inductor but the schematic symbol is clearly a capacitor.
4FunandProphet
Not actually a prophet...
Join date: Jan 2008
10 IQ
#3
Honestly, I would sell it and buy a newer C50 that has an effects loop. Easier, and fairly cheap considering what they go for used.

If you really want to pursue this, I would contact Peavey and get the specs on all the components on the board. You need to know their design value and also their voltage rating, as that makes a great difference in which components you buy. Hopefully the original is higher resolution that the one that posted, because I can't really make out anything on it. If you're decent enough at reading a schematic and soldering, then you should be able to build one without issue.
redhothoshi
Registered User
Join date: Jul 2011
10 IQ
#4
The original is much much easier to read.



While it would be easier in theory to sell it, I don't think I'd be able to sell it locally and I don't really feel comfortable shipping it.

The schem has 27V power going through everything, I think, wouldn't it be safe to assume that as long as I use components rated higher than 27v? I've really only worked on pedal circuits before.
The only problems I run into looking at this schematic are that the caps are all missing units and I'm not sure what the o/z thing is on/around J87.