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
I posted a similar cry for help several weeks ago, concerning one of my Bryston 7B-ST's, but never followed up with Bryston's fix: they found, and replaced in a very quick turnaround, a faulty switch (the one which selects series or parallel operation).

Now get this: I sent the unit from TN to Bryston's repair facility in NH on a Thursday. It arrived in NH the following Monday; they repaired it and had it on its way back to TN Tuesday, scheduled for delivery on Friday. In fact, however, although UPS tracking showed it "out for delivery" all day Friday, it was not delivered until the following Monday! I'm still convinced the guy in the brown truck on Friday decided to start his weekend early and let some other schlub deliver the amp later.

I was relieved to find no damage. That would have been the icing on the cake.

Bryston is a class act!
Earnestmoney, I can't believe what you wrote about packaging up the amp...

I already went to Home Depot and found that 4'x8' sheet of foam insulation and decided that it would make great packaging material. Right after I left Home Depot I went to U-Haul and bought a box!

I do not have the original box, but I am going to double box it with the 2" insulation in the first box and something a little thinner in the outer box.

I am worried about the return home, though. Classe told me that they will put the amp in an original box before they send it back to me, but I'm wondering if they will put that box in another well packaged box.
Ketchup--

I don't know what sort of packaging Classe uses, but if it's up to the quality of Bryston's---and I'd be surprised if it isn't---you've got nothing to worry about.

Bryston uses a double box, of course, surrounding a two- piece construction of thick, resilient, tough, cellular plastic, which totally fits and surrounds the amp. I think it would survive anything short of an attack by a mad forklift.
Hey 914. I could rant endlessly about UPS and FedEx screw-ups as I was at their mercy to deliver $120 Million annually in aircraft engine hardware. They delayed my engine lines countless times over the years.

Bryston must indeed be a class act based on the service you received and the testimonies of many other A'goners.

Ketchup, you cracked me up with the Home Depot/U-Haul story! LOL. Had you already made the rounds prior to my post, or was their some kind of mental telepathy going on here? ;)

Based on my experience, overkill packaging is always worth the peace of mind. Classe's original box and internal packaging is probably of superb quality. However, I would offer to pay extra for double boxing.

I like Counterpoint's return policy. They require that you ship your amp in a wooden crate and they will return your amp in the same crate. They supply decent crates for $80 plus shipping.

I design and build gorilla proof crates myself, that I plan to market to A'goners. I think they are good for several shipping cycles of serious abuse. Sorry I don't have anything already built that would suit your needs.

Regards,
Earnestmoney, I had already gone to the stores before you replied. I'm a few steps ahead of you :) I actually ended up going to Lowe's and found a different 4 x 8 sheet of foam. This stuff was actually white styrofoam and offered a little more cushion than the stuff that my Home Depot had (very hard yellowish looking stuff). It was a few more bucks, but worth it.

After a few hours of sculpting foam I ended up with 4" above and below the amp and 3" on the sides. This is all inside a double walled box. Then, I wrapped the box in thick carpet underlayment and encapsulated that with another box cut to fit tightly around the padding. I did this to offer some shock protection in the event of a fall. Overkill? Probably, but at least I'm not going to worry about it.

If anyone wants to ship me a loaner amp for the time being feel free!