Mesa DC-10 (low volume problem)

[Jason B.]

Hi guys, haven't been around in a while. I used to hang out on the old Ampage forum years ago.

Regardless, I need some assistance. I have a Mesa DC-10 that is having some issues.

First off, i have no schematic for it. Anyone have a copy they could email me?

The amp turns and plays fine. After a few minutes of playing, the volume drops drastically and it gets a bit harsh sounding. If left alone, after a few minutes of sporadically trying to cut back in in, it cut's back in.
I did notice that when the volume drops, I can turn off the power to the amp and wait for a few crackel sounds in the speaker, and then turn the power back on and it's fine.

After 15 minutes or so, this all stops and the amp will play fine from there out.

Doesn't matter which channel I use, problem still exists so I'm assuming it's not a pre-amp issue.

HELP!!!

Boogies never have been my thing. Any ideas or suggestions?


Jason

[R.G.]

Hi guys, haven't been around in a while. I used to hang out on the old Ampage forum years ago.

Regardless, I need some assistance. I have a Mesa DC-10 that is having some issues.

First off, i have no schematic for it. Anyone have a copy they could email me?

The amp turns and plays fine. After a few minutes of playing, the volume drops drastically and it gets a bit harsh sounding. If left alone, after a few minutes of sporadically trying to cut back in in, it cut's back in.
I did notice that when the volume drops, I can turn off the power to the amp and wait for a few crackel sounds in the speaker, and then turn the power back on and it's fine.

After 15 minutes or so, this all stops and the amp will play fine from there out.

Doesn't matter which channel I use, problem still exists so I'm assuming it's not a pre-amp issue.

HELP!!!

Boogies never have been my thing. Any ideas or suggestions?


Jason

Divide and conquer. Pull the first preamp tube. Still do it?
How about the next tube? Next? Pulling which tube makes it quit?
Does the volume control affect it?

Give a read to the Tube Amp Debugging page for some discussion of how to proceed when you need to isolate which section is a problem.