Question on old AL-811

[Lloydxi]

Greetings everyone.

I have an 811 and a 8111H amp. I've had the H for tear and recapped, redone the diodes, resistors etc. Easy to trouble-shoot, yeah right. I have a newer 811 3 tuber that has me a little vexed. The bias resistor that usually blows when the tube shorts isn't obvious on this one. It still blows the fuse when new tubes are installed.

Any thoughts are appreciated. I want to know where to look for the fault before I dig in too deep.

Thanks and best wishes for the new year?

 

[nomadradio]

blows the fuse when new tubes are installed

Does this mean it won't blow the fuse with the tubes removed?

A shorted tube will do this. Does the plate meter slap to the right when the fuse blows?

I don't recommend this method, but connecting only one plate cap at a time could narrow down the culprit, if the fuse blows with only one of them connected.

73