best source for capacitors..

[Bob Carlucci]

Planning on replacing the power supply capacitors on 2 old Peavey 400 series amps.. One is a session 400, the other a Musician 400.. Both are old silver knob models with a sweet sound,, Both work well, are very powerful, sound VERY good, warm, clean,etc[for SS amps], and both have the identical issue. No AC hum at idle to speak of, but a lot of those quiet"explosion type sounds, like the low rumble of far distant thunder.. Other times, more of a "popcorn" type sound- at idle only.. I am NOT an amp tech, but actually have repaired many over the years, and yes I know how to discharge power supply caps without electrocuting myself, and to NOT!! install them with the polarity reversed, so please no "take it to a qualified tech" comments.
I am handy with a soldering gun, and its just not worth spending $500 on 2 amps that are probably not worth $300 combined.. good source for caps at a reasonable price would be great, and any other advice would be appreciated... While in there, I plan on checking all connectors, grounds, reverb transformers etc, but as stated, the only problem with these amps, is low rumbling, and popping sounds at idle, otherwise they function perfectly, and I think the caps in both are original... Hoping new electolytic caps will do the trick, and thats where I want to start...again, any help greatly appreciated... bob

[Mike Scaggs]

Google

Mouser

DigiKey

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Places like Mojotone, Antiques electronics, etc normally only carry tube amp related stuff.

I can tell you a few local tech in Nashville have stopped taking Peavey amps in for repairs as they cannot get parts any longer, FYI.

Cheers

[Bob Carlucci]

Google

Mouser

DigiKey

-----

Places like Mojotone, Antiques electronics, etc normally only carry tube amp related stuff.

I can tell you a few local tech in Nashville have stopped taking Peavey amps in for repairs as they cannot get parts any longer, FYI.

Cheers

Understood, but I figured electrolytic caps are pretty much standardized, and as long as the values were they same or perhaps a bit higher, you were fine... There should be nothing "brand specific" about power supply filter caps correct?

[Mike Scaggs]

Google

Mouser

DigiKey

-----

Places like Mojotone, Antiques electronics, etc normally only carry tube amp related stuff.

I can tell you a few local tech in Nashville have stopped taking Peavey amps in for repairs as they cannot get parts any longer, FYI.

Cheers

Understood, but I figured electrolytic caps are pretty much standardized, and as long as the values were they same or perhaps a bit higher, you were fine... There should be nothing "brand specific" about power supply filter caps correct?

The electrolytics may very well be a common value but the filter caps in Peavey are much different than tube amps. Give Mouser a try.

[George Erdman]

...
I can tell you a few local tech in Nashville have stopped taking Peavey amps in for repairs as they cannot get parts any longer, FYI.

Cheers

Oh joy, no parts?...but I wont take that "Cheers" as a sarcastic ..."have fun with that..." This forum and its members feels far too well behaved for that...

In talking with folks it seems a lot of Peavey amps were specifically built with unique circuits (e.g. reverb units). So Mike, what is it about PV power caps that make them different?

Bob, glad to see you've decided to resurrect your own versions of Lazarus. I can't stand seeing a perfectly good amp being trashed because parts and/or attention. That Session 400 sounds like it would be so sweet. Was very temped when you had it up on Buy/Sell. But alas, not to be...Along the lines of raising the dead I'm about to embark on completely refurbing a 112's patch board. Remove old components, repair pads, traces, replace with new caps and resistors as spec'd. Hell, there's even a few more of those old 4560 OpAmps on it in addition to those already on the preamp board...its current condition?...simply put, its butt hair ugly.

George

[Mike Auman]

Bob, in the US, Mouser and DigiKey are you best bets for caps like that. The Session 400 has two 6000 uF 45V caps after the rectifier, both DigiKey and Mouser carry a 50V 6000 uF cap that should work, but compare the picture to what's in your amp. The caps in your amp will also have the capacitance and voltage ratings printed on them. https://www.digikey.com/en/products/det ... 2A/5609746 They'll run you about $60 each.

[Bill Sinclair]

Sprague capacitors like those at Digikey have gotten crazy expensive. It's hard to justify spending $120 on caps for a $200 amp that may not fix your problem anyway. Here's a 6000ufd 40V at Newark for about $15 each. I can't tell you if they're any good. Of course, you'll need to check the dimensions to make sure they fit.

https://www.newark.com/cornell-dubilier ... dp/69K1890

[Bill Terry]

I'm pretty sure those filter caps are axial lead, the snap and terminal type would require more 'handy' work to wire up and secure properly. These aren't as cheap as they used to be but Mouser seems to have a reasonable replacement. Unfortunately, the lead time is listed as 28 weeks, which is pretty close to 'never' in my experience.

https://www.mouser.com/ProductDetail/Vi ... 682G050JP6

[Raybob Bowman]

https://www.tubesandmore.com/

[Pat Chong]

(I hate to say this, because of counterfit crap being sold sometimes, but:)

6800 mf at 50 vdc, vertical mount, ebay, $4.95.
If you need more than 1, the price goes down.

Luck............Pat.

[Michael Hartz]

Mouser gets my vote, bought alot of capacitors through them building pedals. Great prices. Did the Brad Sarno Peavey Session 400 cap job several years and ordered everything thru them, no issues.

[Donny Hinson]

My experience tells me that those types of noises can come from other places, too. Cold solder joints, bad small caps (not the power supply ones), or even a bad resistor. And don't forget to clean all the Molex connectors.

[Raybob Bowman]

My experience tells me that those types of noises can come from other places, too. Cold solder joints, bad small caps (not the power supply ones), or even a bad resistor. And don't forget to clean all the Molex connectors.

I concur. Bad filter caps, if the amp works at all, usually sounds more like the ocean after being on a little while.

[Bob Carlucci]

Found a leaky cap that was 500uf,35 volts... Replaced it,,, noise was still there.. The 2 huge power supply caps looked good, no leaks or bulges.. They are the size of Red Bull cans!... There is no hum, and the amp works perfectly, as does the Musician 400 I also have from the same era.. They both have that kind of muffled "popcorn" noise at idle.. It bothers me only because I know its there.. There are no issues at all with hum or distortion, or any function of the amp not working. Both amps are perfectly usable and sound great... I have talked to electronics repair guys locally, and they seem to think bad caps in the power supply would more or less cause louder 60 cycle hum,, not this popcorn,"muffled distant thunder" type sound.... I was thinking it could be one of the 5 transistors I see in the circuit board 3 in the preamp and 2 in the power amp , possibly drifted out of spec... I think the output transistors would cause a lot bigger problems, but not sure... I dunno, not sure what I am going to do as yet.. I can't justify spending $200 to fix an amp, I could only sell locally for $75-100 or so... No one wants old Peavey SS amps any more, ... If they were tube amps I'd spend the money to get them properly looked after.. Tried to trade this very nice Session in for a mere $50 to a local guitar shop that do repairs on guitars/amps.. He didn't even want it for a $50 store credit, with a blown D130 JBL, that he knows how to recone...I have been doing business with him for many years.. This tells me he knows the market, and figures by the time he takes the needed labor time to go through the session 400, replace a few parts etc,that he couldn't make it profitable,... Junk old raggedy tube amps, with 8 or 10 inch speakers and 5 watts, go for $500 everywhere I seen them, mostly old Valco,Univox, low end stuff like that... Anything sold state, in most stores these days, sits forever, and when finally sold, go for peanuts... The fact that I can't even get $50 for this powerful amp tells me all I need to know about putting much into it... No complaints, I only paid $20 for it!.... bob

[Pat Chong]

Hi Bob,

I have run into this kind of problem, before. The amp kept coming back for the same problem.

I had to let it run and run and run untill I finally found the problem. It was a low value cap that (when it got hot) shorted. I had a Sencore cap tester to locate such a capacitor, but is, indeed, hard to locate unless one either locates the "short" or has the tool to test the cap. Using "freeze" spray helped, too.

The cap tester tested for capacitor value, E.S.R. and rated voltage leakage........

Luck on your work........Pat

[Bob Carlucci]

Hi Bob,

I have run into this kind of problem, before. The amp kept coming back for the same problem.

I had to let it run and run and run untill I finally found the problem. It was a low value cap that (when it got hot) shorted. I had a Sencore cap tester to locate such a capacitor, but is, indeed, hard to locate unless one either locates the "short" or has the tool to test the cap. Using "freeze" spray helped, too.

The cap tester tested for capacitor value, E.S.R. and rated voltage leakage........

Luck on your work........Pat

This noise starts the instant the amp is turned on. Same exact on both amps..Actually if anything, its less noticable as you play the amp.. On the Session it actually stops for periods of time.. The Musician head has been doing it for probably 10 years, and the amp still works and sounds great.. For my needs these days, there just isn't any point in spending a lot of money on the session, because I don't plan on keeping it. If were still gigging I might keep the session, get it fixed,but I just have no need for a 200 watt SS dedicated pedal steel amp... Anything I do these days can be done with 25 watts or less... I will most likely just sell the session at a "can't pass it up" price to someone that has the ability to track down these sorts of issues.. Its a great amp works and sounds terrific, and only the amps owner would know it wasn't right, and then only in a quiet room with the amp idling.. Under stage conditions you wouldn't hear a thing unless everything was dead quiet, and you listened close to the amps speaker..