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Replacing Caps in 80's Peavey guitar Amp. Need Advice

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myequation

New Member
I'm hoping to upgrade/replace all the caps in my old 35w Peavey guitar amp.

I've worked with vintage radios in the past, so I have "some" experience with replacing caps.

With this amp Im not sure what replacement filter caps would be best?
I can see its 2200uf but what voltage?

**broken link removed**

**broken link removed**


Im also trying to determine what kind of resistors this was?
That might be brown/ black/ black/ brown strips?
**broken link removed**


Any help & advice would be great.
 
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Nigel Goodwin

Super Moderator
Most Helpful Member
The voltage rating on the capacitors is probably on the other side of the capacitors, when you take them out you wilkl be able to read it - but just measure the voltage across the capacitors, and pick the next highest voltage available.

As for the resistor, you need to consult the circuit, as it's 'burnt up' and the remaining colours probably are nothing like they should be.

Is there something wrong with the amp?, a blanket change of the capacitors is probably pointless?.
 

myequation

New Member
My amp "Peavey Backstage plus" is working.
But it did sit in a basement for about 7 years unused.

Im thinking that a cap replacement would be logical.


a schematic would be great but I didn't see one on that website.
 
Last edited:

Nigel Goodwin

Super Moderator
Most Helpful Member
My amp "Peavey Backstage plus" is working.
But it did sit in a basement for about 7 years unused.

Im thinking that a cap replacement would be logical.

Most probably it's not required, it's certainly not something I'd do without reason.

a schematic would be great but I didn't see one on that website.

No, unfortunately.

Is the resistor in series with the 100nF capacitor next to it?, and across the speaker output?. If so it's a Zobel network, and the resistor is probably 10 ohms or 4.7 ohms - it's not critical.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
Well its from 1985 and does hum alittle, would that be a good reason?

Guitar amps do usually hum a little, it depends under what circumstances - even assuming a fault, repairing the fault would be an easier option than a blanket change.

The 'blanket change' scenario is really from VERY old valve gear, where the quality of capacitors wasn't very good - and that was mainly non-electrolytics as well.
 

tvtech

Well-Known Member
Most Helpful Member
Bad leads??. I have a NAD 3020A from yonks back...still works like a charm.

Almost 20 years without issues. That was an Integrated Amp of note.

Cheers
 
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