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 - 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. |
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 |
Thank you, @imhififan , screw in terminals as well! I will need to get my amp down and the bottom off to measure and see if they will fit. Thanks again! |
The power capacitors in the power supply and in the other areas of the power supply usually begin to swell up and then that is a pretty good sign to replace them. The other reason to replace them is sound quality. I just recently upgraded the power supply capacitors and resistors in an older Spectral power amp and it went from OK sounding to excellent sounding. Bass and clarity plus smoother sounding. |
