Dying OR120

[adangerlg]

So I plugged in my OR120 reissue tonight for the first time in a few months and it sounded fine for a few minutes and then all of a sudden the volume got cut in half (at least). No fuses were blown and all the power tubes were all lit up. I took out all the tubes (including preamp tubes) and reseated them. They all *look* fine, although I'm not really sure how to spot a bad tube.

Any opinions on what the problem could be?

THANKS!

[gldtp99]

Most likely a tube problem----- testing the tubes with a quality tube tester is the best way but substituting known good tubes is another way to find the bad one(s).
If you have known good spare 12ax7's then try them in the preamp slots----- if you don't have a new quad of matched EL34's handy (and you can safely bias the EL34's)--- then i'd suggest taking this OR120 to a qualified tech.
If an EL34 or two went bad there's a possibility that a screen resistor(s) also needs to be replaced---- this needs to be checked out by a knowledgable person.
The big Oranges run the output tubes harder than many other brands of amps so it's entriely possible that there was an EL34 failure---- especially if the EL34's in it had a lot of hrs on them.................gldtp99