Replacing caps in vintage amps, yay or nay?

Bad Brain

Bad Brain

Well-known member
If play regularly, amp sounds good, no leaks/bulging, would you still replace just to be safe? And by vintage, I mean 40 yrs +.
 
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Yes without hesitation. Unless you like driving back and forth to the tech when the next cap's shelf life has ended. I guess for home use it wouldn't matter but all my techs try to preserve "vintage" if it ain't broke but I'd rather just cut problems off at the pass because I have to gig it so sometimes I get on my guy about that. I'm not a collector, and I'm not sentimental. If you are working it hard regularly it's just a matter of time before problems crop up. If it sits in your living room and never gets past two on the vol it might matter less but I aim to break my stuff each time I gig it.
 
You can have them tested for ESR leakage and capacitance if you want to keep them as long as the amp is played regularly at least every 3 months is usually good. I finally had to replace the 3 50/50uf LCR caps from 1994 in my 72 Marshall recently, two had a high ESR values in single stages but the capacitance were still within spec and one cap was still good on both. All my amps get played regularly.

I replaced the LCR's with ARS 50/50uf caps and the amp sounds better and is more quiet than with the 31 year old LCR's even though they weren't leaking electrolyte or bulging. If they test good and not leaking or bulging it's up to you.

You might find this video by Fryette informational and interesting.
 
Yes without question. Don’t care how much you do or do not play it, replace failing and tired electrolytic capacitors always.

I don’t care how old they are or how vintage it is. At 20 years old on the date codes they’re scrapped and replaced. Anyone that argues otherwise can find someone else to work on their great gear. I refuse to cater to the snubby OEM must be vintage crowd over user safety and amplifier performance.
 
Always change the electrolytics in the power supply.
The 10uf/100V bias supply filter caps should definitely be changed even if the even if you decide the keep the 50/50uf Daly caps for the mains screens and phase inverter if they are in good shape.

If those bias supply cap go while the amp is operating it can take out tubes and an output transformer and ya don't want that. If those are still original Eries those should be changed for sure.

I would think originals from 1978 are at the end of their lifespan for sure.
 
Yes without question. Don’t care how much you do or do not play it, replace failing and tired electrolytic capacitors always.

I don’t care how old they are or how vintage it is. At 20 years old on the date codes they’re scrapped and replaced. Anyone that argues otherwise can find someone else to work on their great gear. I refuse to cater to the snubby OEM must be vintage crowd over user safety and amplifier performance.
man, I can't believe I'm nearing the 20 yr mark with a couple amps I bought new. Thought I would never need to worry about it buying new, gat dam I'm gettin old. :LOL:
 
I need to replace the power tubes in one of my VTM60 heads. Considering replacing all the important caps.
 
Fryette says leave them..
Interesting. FWIW (This post was 15 years ago)

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