Multi-section can capacitor last longer?

[Axtman]

Maybe I am wrong, but I have found that multi-section can capacitors to last a long time in old amps. I have only occasionally had to replace one. On the other hand most individual filter caps I find under the Fender "dog house" are bulging, leaky and are replaced.

[The Dude]

I'm not sure that's true. Could it be that leakage and bulging are just more evident on a paper cap than a metal can?

[Leo_Gnardo]

I'm not sure that's true. Could it be that leakage and bulging are just more evident on a paper cap than a metal can?

Besides bulging - out the end mostly - and goop, crud, spuzz etc leaking out, one of the signs of a failing cap is it heats up noticeably when charged to full or near-full voltage. Of course testing whether it's drawing current while fully charged would be a big clue but that would take a meter.

[pdf64]

I was happy to leave the 1957 date coded (Plessey I think) can cap in a Watkins Westminster I serviced a few years back. After a slow reform, try my best but I couldn’t find fault with it or reasonable grounds to replace it.
But that’s a notable exception, old can caps typically have blown seals.

[tdlunsfo]

I realize I haven't been doing this as long as most but finally came across my first blown cap can complete with bulged top and tar like goo spewed all over underside. What a mess and a shame as it also took out a vintage Scott output transformer.

[Leo_Gnardo]

I realize I haven't been doing this as long as most but finally came across my first blown cap can complete with bulged top and tar like goo spewed all over underside. What a mess and a shame as it also took out a vintage Scott output transformer.

Is that a 299? If you need iron send me a PM. Great sounding amps when they're working.

[tdlunsfo]

It's an lk-72-b which I think is the same amp. I actually just purchased an OT off ebay from california as it was an exact match and reasonably priced. I'll keep you in mind if the other one starts acting funny. It threw me for a loop. I spent the better part off a day and half pouring over the PI trying to figure out why the gain was so off on the right side and why I had hardly any current draw/wattage. Once I grew a brain and measured the OT primary it all made sense. Guess where the first stop out of that cap can went to?

[Axtman]

I always check out electrolytic caps with an ESR meter.....usually after I have removed them and before they go into the trash bin. As I have said before, I usually don't find issues with the multi-section cans so I don't replace them. Maybe I am an idiot and should replace them just as a matter of procedure.

[SoulFetish]

Yeah, I can't say that in my experience I've found can caps to be less prone to failure than other electrolytics. What I have found though, is that the individual sections will not necessarily have the same life cycle.
We often have to replace one section of the can, while the other(s) are performing fine.