Rectifier Failure Mod

Amplifiers contain voltages high enough to Kill you even after the amp has been powered Off !!! If you don't have enough electronic experience to identify and discharge the Filter Capacitors which contain these Deadly voltages, take your amp to a Qualified tech. If you don't know a qualified tech in your area, post a request in the alt.guitar.amps newsgroup, the folks there will be happy to help you.

The Mod:

Think of this mod as a form of Amp Insurance. If the Rectifier in your amp ever shorts out (which has been known to happen), catastrophic failures of your power tubes, power transformer, and output transformer, can follow. This would translate into a few hundred dollars worth of damage, not to mention ruining the value of your amp by requiring replacement of the original transformers.

1. Install 1500Volt 1A Silicon Diodes in Series with the two sections of the rectifier tube.

If the rectifier tube ever shorts out, the B+ will go up by about 50V. Then the diodes will take over for the shorted rectifier and the amp will run a little hotter. (Basically the same effect as if you had installed a Solid State Rectifier). The higher voltage can quickly ferret out any old or dying caps by causing them to fail. But any cap that does fail probably should have be replaced anyway.