Capacitor Temperature ratings

[ncboy654]

I'd like to replace the multi cap in a PR with a 30/20/20/20 but it only has a 55C rating, the stock 20/20/20/20 is 85C. Will a 55C cause problems since it is so close to the power tubes?

[pila]

I used a 40-20-20-20 in mine. Anyway, it's just under 2 inches away from the power tubes, and I really doubt if it will absorb too much heat.

[R.G.]

Originally Posted by ncboy654

I'd like to replace the multi cap in a PR with a 30/20/20/20 but it only has a 55C rating, the stock 20/20/20/20 is 85C. Will a 55C cause problems since it is so close to the power tubes?

It will have a shorter life if the internal temps get anywhere near 55C.

The temp rating on a cap is a statement about working life at that temperature. The maker warrants X power on hours when used at the rated temperature. This is usually based on the electrolyte material and where it begins to degrade. There is not only the standard lifetime-halves-per-10C-rise, but there is some temp where the electrolyte chemically degrades producing a fall off the cliff.

If you can get an 85 C part that is far more advisable. But if you CAN'T get an 85 C part, use the 55C as a stand in so you can use the amp while you find the perfect cap.