Hi,
All of a sudden my Fender Hot Rod Deluxe has started to add noise and a sympathtetic distortion to the note "A". It seemingly does not matter where on the fret board I play it. Is this a sign that there is an issue with the tubes? And if so, how do I figure out which one(s)?
TIA.
b
Could well be a tube. Best way IMO to diagnose that is substitution with a known good tube. You need to keep spares around, anyway. Next best way to narrow it down in a hurry is to swap around tubes of the same type in different positions. You have several 12AX7 "preamp" tubes. If you swap two of them, you should hear a difference in the distortion if one's bad. After you've gone through the combinations of that, if you still have a problem that didn't change, the "power" tubes are suspect. Normally they wear out fastest, anyway, but there are always exceptions. "Sudden death" type failures are most common in new tubes, but worn tubes that have lost emission capacity tend to show it by abnormal distortion and noise.
"A cheerful heart is good medicine."
