Fender 65 Deluxe Reverb

[bsco]

Just in case somebody else has this problem... A loud hum coming from this amp(a newer version with a printed circuit)...even with volumes down...sounded alot like power supply hum......So I checked out filter caps, etc, etc.....checked dc voltages and the like.....couldn't find the source.....Removed all tubes and reinstalled them one at a time.....installed power tubes together of course....no hum was found until I inserted the 1st stage tube...a 12AX7....this was causing all this hum....the next time tubes will be the very first thing I will check for these types of problems..by the way, the tube tested ok in a tester..no signs of leakage or shorts....goes to show you can't depend on testers.....direct substitution is the best way to go....especially in this case..

[Enzo]

testers are all but worthless to me. I have one I never use. A tube tester can verify a tube is bad, but can;t really tell you a tube is good. About the only thing it might be useful for is matching emissions.