Fluctuating volume in one channel: Part II


I posted a few days ago about my left channel volume fluctuating from time to time. I got advice saying that it was most likely either the tubes in the preamp or a bad solder joint on an interconnect.

I switched the tubes in the preamp from left to right and right to left and the problem stayed the same (left channel fluctuating). Then I switched the ICs between the preamp and the amp from right to left and left to right. The problem stayed the same (left channel still fluctuating).

I did not bother switching the ICs from the cd player to the preamp because the problem remains even if I listen from a different source.

What is next in line for me to test? If you would like to see the other thread, it can be found here:
http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1087439704&openusid&zzKetchup&4&5#Ketchup
Forgive me for starting another thread, but I know old threads don't always get read.
ketchup
You have probably reached the point where you need to take it in for service as you probably don't have the testers that can find a short.

On new vs. old threads I have found that the people who have been of previous help on a problem are often the ones I would first go back to and your new posting appears in their "My Threads" page and I, for one am usually curious enough to check out the latest.

Also, I am attracted to even the old threads that have multiple responses.
I had a similar problem many years ago. The volume would fluctuate in one channel with a little static. I narrowed it down to the crossover pot in one of my speakers. I twisted the pot quickly back and forth for a couple minutes and my problem was solved. I followed up with some Radio Shack tuner cleaner.
Hello Ketchup. Did you get your system working properly yet? I hope you haven't had to go without music all this time.

Regards,
Earnest, I have been listening to music for about 5 minutes at a time... after that the left channel cuts out. It's pretty rough :(

I narrowed it down (without a doubt) to a faulty amp. I spoke with Classe and will be sending it back as soon as I get it packaged up safely. I hope their customer service is good!