Preamp issue?

I'm voting for tube issues too. I've had power tubes go bad very quickly, leading to popping, crackling and the like.

The good thing about my pre coming with crappy Chinese tubes was that I replaced them immediately, leaving me a spare set (of inferior quality..) to diagnose problems with as to use while I wait for good replacements.

The first troubleshooting step should be to swap the interconnect cables at the amplifier input end and see if the issue moves to the other side. This will show that the issue is in the pre-amp (or possibly source) and not in the amplifier. If you determine that the issue is in the pre-amp or source, you can forget about troubleshooting the amp and speakers. You can swap other cables to isolate the pre-amp or source as the cause of the issue. Once you know the problem is in a certain component, then troubleshoot that component. If it's the pre-amp, swap the tubes side to side to see if the problem moves.

Of course, turn off the power to everything when you're swapping cables and especially tubes......

^^ What reubent said. Swapping the interconnect cables left for right is your first step, otherwise you don't know if its the preamp or the amps.

tubes dont last forever......it might be time for a new ones.

Thanks for the feedback... will swipe the tubes next.
I have replaced tubes in my amps in the past so this isn't anything that I am afraid of doing...I just didn't think that this "symptom" is characteristic of dying tubes.
Kind of weird for the pre-amp to "lose" some power in one channel.
Was more thinking of issues with resistors or other parts.

BTW - I have verified for sure it is the preamp and no other part of the system, including the interconnects etc...

Will get back to you guys tomorrow after testing...

Thanks!