SS rectifier diodes?

[Leo_Gnardo]

Can't say I frequent Audio Asylum much.

Thought I'd seen your avatar over there. Sort of a what the heck is this? moment.

On paralleling rectifiers, I'd be concerned one has a different conduction threshold than t'other, iow one would be hogging the current whilst the other loafed. Same batch - better chances of a balance. And a quick test with ohm meter might quickly reveal a compatible pair. But I'd still go the 1N540n route for over 1 amp service. If you've been getting along with parallels, "more power to ya."

[trobbins]

I'd suggest the stress is only at turn on initial first pulse. The diode VI curve at such a peak level is dominated by the bulk device resistance characteristic, rather than the threshold voltage - sharing tolerance is highly likely to be covered by 50% derating. All other normal operating conditions are far more benign.

But that does bring up a concern about device stress. If a protective fuse has blown, and the effective supply source resistance could allow current peaks near the non-repetitive rating to occur in to a fault, then best to replace the diodes as well as the fuse. That is normal advise for industrial diode and scr applications.

[gui_tarzan]

Enzo made a good point regarding these on another thread a while back. If the difference between 1N4004, 5, 6 and 7 are just working voltage, why not use the 4007 to replace all of those? Nothing can be hurt by the higher voltage rating and if someone can notice a sonic difference between them then their ears are a lot better than mine. I usually replace them in Fenders that I work on when I do the caps. Most of the originals look like dog doo so I figure it's cheap insurance.