Need a little help with a 1965 Deluxe Reverb

[haroldoftherock]

My vintage 65 Deluxe Reverb has been acting up as of late.  The last couple of gigs I have played, the amp starts to distort pretty heavy.  I was using a telecaster at the time and when I rolled up the volume on the guitar it got dirty almost like using a fuzz pedal, when I rolled off a bit it was playable again.  I switched to a gibson and had the same problem.  I then switched to straight in with a known good cord and still had the problem.  I've also had a problem with the amp disappearing out from underneath me when holding a high note.  Does this sound like a tube issue?  I had a cap job done about a year ago.  I appreciate any trouble shooting advice.

[Dave]

If you had a cap job done, and it was a good cap job, then it is probably a tube.
However, there are a lot of shady "techs" out there. I had a friend come over once with a vintage 65 Deluxe Reverb that had recently had a cap job. I opened it up to find that every cap in it was original. He had paid the same guy to change out the caps every ten years and the guy never changed a cap.
"Techs" will sometimes prey upon the ignorance of the customer much in the same way a mechanic does.

Dave

[rafe]

Could be biased to hot? perhaps a resistor has drifted? If it's not caps or tube... You might be able to watch the tubes in a dark room while you are playing.... Do they glow cherry red when you play hard?

[phsyconoodler]

A tube amp owner with no spare tubes is like a car owner with no spare tire,driving in the country with 'no gas stations for the next 100 miles'
  Get some spare tubes and keep them on hand for days like these.You can easily swap tubes and see if it's tube related.

[haroldoftherock]

Thanks Folks.  I fired it up in the dark as suggested and the tubes are glowing a bit when I hit it hard.  I'm going to try a re bias first and if that doesn't work, I'll sub out the power tubes.  Would there be any ill effect coming from the rectifier or pre-amp tubes or am I just looking at the power tubes as my main culprit?

[dude]

Looking for power tubes running too hot, the glow is like an orange/red round hot spot on the plates (around the middle of the tube). This glow is different than tubes just getting more intense as you play harder. Looks like a glow that's the size of a nickle, orange/red that size.

It could be a preamp tube too, try replacing one 12AX7 with know good tube one at at a time. Also sometimes a loose fit in a preamp tube can be the culprit too, try wiggling each. If the wiggle works, you might re-tighten the tube pins in the socket with an ice pick. 

al