life span/failure rate of filter capacitors?


(And I assume that the filter caps are the large electrolytic caps with the screw in terminals?)

The reason I am inquiring about this subject is that I stumbled on to an older thread started by someone who had a "filter cap explode" inside his 20 year old Cary V-12 monoblock.  (Which is basically what I have, only mine is a single stereo amp.)

Anyway, I do know the specs on those large caps with the screw in terminals which I am thinking are aka filter caps are 560uf 400v. 

Do these normally give any kind of warning before they let go?  It does occasionally blow the 3A SB AC power fuse on start up. 

TIA for any information/advice on this subject.

immatthewj

Well, whatever I suppose. Are you going to replace to caps? If so, I think you could go nicely upscale for a nice uplift, anything in mind?

Yes, @rickysnit  , I think it would be a good preventive maintenance action to take.  As far as having anything in mind, no, I don't know much about that stuff.  I have been looking on line (including Partsconnexion) trying to find the value I need (400 v, 560 uf) with screw in terminals, but I cannot find anything matches.  I suppose I could do a mod to convert to snap-in or solder, but I really don't want to do that.  I plan on actually calling Partsconnexion on the phone next week to find out if I am missing something on their site. I guess I could also call Cary (sales department, because they no longer provide telephone tech support) to see if they will sell me the power caps by a telephone sales.  Their Mundorf signal caps re priced pretty high on their site, so I am sure I would take it up the wazoo if I bought the power caps from them, but at least I guess I would know I was getting replacements that would work.  I would hope.

@immatthewj  - Yeah, you can have filter caps fail becuase of something else down the chain.  Amps, because of the high amount of current, are particularly subject to all sorts of cascading failures.

The other way can happen as well. Bad filter caps can fry the rest of the amplifier, or the main power transformer.  Especially a bad thing with vintage amps that use transistors no longer made.

I have been looking on line (including Partsconnexion) trying to find the value I need (400 v, 560 uf) with screw in terminals, but I cannot find anything matches.

400V is the minimum, higher voltage rating is better. Mouser has some 560uF 550V in stock.

Ambient temperature and internal heating due to ripple current is the most critical to the life of aluminum electrolytic capacitors. Although higher temperature rating is better, you also need to check the service life specification.

An aluminum electrolytic capacitor rated 85°C with service life of 18,000 hours can outlast one with 3,000 hours @ 105°C if working at ambient temperature lower than 85°C.

https://www.mouser.com/ProductDetail/KEMET/ALS60A561KE550?qs=nJQ%2FaDFn8AFl3GSdgkk75g%3D%3D