Replacing power filter capacitors

[hearforever]

When replacing old power filter capacitor cans is there any danger/problem in wiring new caps of the same value in parallel with the old can terminals? I know that a tube rectifier often has a maximum value on the reservoir capacitor. I have already disconnected the reservoir capacitor from the circuit... but now I'm wondering about the others. It would certainly be easier than wiring a terminal strip. Thanks

[lowell]

I wouldn't. It defeats the purpose. If the old caps are leaky, or worse, they fail, then bye bye fuse. Old caps in parallel with new caps= potential failure. Not to mention changing the feel of the amp by having doubled the capacitance of your supply nodes.

[gbono]

Jupiter capacitors home page

Sorry to drift this topic but someone at work mentioned this capacitor "technology" and I thought they were joking. When was the last time you called a capacitor by its real name - condenser

[olddawg]

Prior to modern "electronic" ignition systems, the capacitor in all car, motorcycle, lawnmower, etc distributors was called a consenser. If you want to keep the can you can always gut it and mount the new capacitors inside with a little hot glue or silicon. It's pretty easy to do with a dremel tool and a cutting wheel.

[km6xz]

Just to "amplify" Olddawg's suggestion. The main killer of caps in functioning circuits is heat and getting the cap on the the top of the chassis in air flow can reduce capacitor core temperature. If they are mounted too close to the power tubes, heat might be higher than under the chassis but a small metal heat shield or vane between the tubes and cap will lower the heat for the caps. The majority of heat generated by tube plates is transmitted away from the plate by radiation so a simple shield can solve that problem for longer life of the caps.