Mark IV lead channel sounds like it's dying?

So on my Mark IV when I was playing through the lead channel the gain sounded like it was dying/fading in and out? It was really wierd. Anyone have and idea what this could be? Maybe something is going out?
thanks

Have you tried to swapp the preamp tubes???

No I have not. I think I'm going to take it to an amp tech and have give go through it and just kind of see if their are any issues he notices. I have a feeling that it may have something to do with the tubes
thanks

I think it's the first thing to check and hope that it will cure the problem.
Good luck,
Normand.

+1 on swapping tubes to see if the problem follows the tube

+1 to the other comments... check yer tubes!

Let's borrow this topic...

So I have a problem with Mark IV. It has started to sound muddy or flubby. I have to crank treble all the way up now...I don't think it's the tubes, 'cause they are quite new. Amp is from the early 90's. Maybe filter caps are going bad? There's no loss of distortion or volume. Just increasing muddiness...Can you help me?

I'm not as sure as you are that it is not a tube problem...
I really think you should look that way before going to a tech.
I once had a problem with my combo (mark 4B) and it was filter cap . The amp was very noisy and i had to warm it something like 2 hours before it began to sound ok. Really hope its not your case. Finally, i sent it to Petaluma and they change the board because a cap has leak on it...
Anyway, cross your finger and chech the tubes.
Good luck,
Normand.

Fixed!! Finally got around to replacing all the tubes and my amp no longer has gain issues on the lead channel. But now I'm looking to trade it for a Roadster. I like the Mark IV, but I just don't think it's the amp for me. i really miss that roadster/recto tone.
thanks for all the help guys
Edwin Song