Golden Tube SE 40 Hiss and Pop problem - Thoughts?

My golden tube se40 is hissing and popping from one channel, and it's getting worse. Anything come to mind?

I know this is a badly designed amp, but I like the sound, just hate the reliability.

For some reason, I'm thinking this was indicative of caps or resistors, forget which. If it was just a tube, I'd be very happy, and need to dianose that.

Thanks,

robert