DC-10 problem

[kkcgtr]

I just picked up a used DC-10 head on Ebay and I'm looking for some advice on a problem. When playing on the lead channel, after about 15-20 minutes, the volume starts to fluctuate up and down intermittently. I swapped out instrument and speaker cables. I thought maybe a tube had come partially unseated from its socket due to transport. I reseated all power and preamp tubes, but it made no difference. The seller says the tubes are only about 2 months old. Anyone ever run into this problem? What are some other things I should try? Any advice would be greatly appreciated. Thanks.

 

[fdesalvo]

Hi! If the problem is only occurring on one channel and not the other, then your problem is a faulty preamp tube. However, if the promblem is not isolated to one channel, then your problem is most likely your power tubes or your driver/PI tube- the power tubes being more probable...

Why dont you turn the amp around and look at the power tubes as you play and see if you can see any flashing or dimming as this occurs- look for a disturbance in the blue glow of the power tubes!

What is your name, by the way?

~F

 

[cvansickle]

I used to have this problem with my DC-5 combo. If I replaced the power tubes, the problem would go away but would come back sooner than it should have with new tubes. I spoke to a local Mesa service tech, and he said it sounded like a filter cap problem. Anyway, I sold the amp so I no longer have this problem.

 

[James]

Seems that alot of us had problems with the DC series, including me.


I had a DC-3 head, and it had bad caps also.

It would always buzz like crazy when I turned it off.


Defenetly take it to a tech, kkcgtr.