by paart » Sun Mar 30, 2014 8:35 pm
A 250 microfarad cap in the input cap position is getting “up there”. I imagine the inrush limiter will contain the heavy “turn on” current surge, but there’s also a possibility that over time, problems could arise. One issue with inrush limiters, is that if the AC power is removed, then quickly returned, as often happens during power “glitches” (thunderstorms) the limiter may not have time to cool and increase in resistance. I’d consider changing the rectifiers from 1 Amp to 3 Amp (ultrafast) devices. Be certain to use a “slow-blow” line fuse, and, if you have a Variac, I’d bring up the AC voltage slowly a few times, until you are certain everything is functioning properly. Be careful when working on the amp; larger caps will take longer to discharge through the bleeder resistors.
I’m an advocate of increased power supply energy storage, but caution is necessary.