I would like thank everyone for their help. I think I have it narrowed down finally. It turns out that their are poorly placed bias circuits on some of the Bryston 14bsst's which can cause "runaway" thermal events upon cold startup. I thought for sure that it was the preamp but after calling Bryston USA tech service they more or less said, "Yes, we know what that is about!" Evidently, there is a diode that was not properly secured on the heat sink of the 14bsst's. I have to send my 85 pound amp to Vermont to have four, 15 cent parts replaced and secured. By the way, I tried every one of respondee's suggestions before I finally narrowed it down. So if there are any Bryston 14sst's out there...beware of this thermal anomaly. Thanks, Jim
Problem with Bryston 14bsst
I seem to have an anomoly of sorts. I have a Bryston 14bsst paired with my deHavilland tube preamp. The music is perfect. I run a Wadia 302 through the pre with very nice results. The other day I tried an old Raytheon 6sn7gt tube in my preamp. I immediately heard loud hissing etc. from my right speaker but before I could shut down the system, the thermal breaker shut down the right output on the Bryston. It was extremely hot. I of course removed the tube and put my old 6sn7 back in the pre. Everything seemed fine for a few days. Yesterday, I turned on the preamp to let the tubes warm up for about a half hour. I got distracted and forgot to turn on the Bryston too. When I did turn on the Bryston it again got extremely hot on the same side as previously. I shut it down. I tried the system again later and everything seemed alright...however now it is doing it again. The Bryston heats up immediately upon the introduction of the preamp. I tried the preamp on the cd output selector and the tuner output selector...same thing...lots of heat on one channel. Here is the kicker. Just for the heck of it, I ran my Wadia directly in to the amp. The amp stays cool and everything is working! Looking at the history of when this started (bad tube) could I have done something to the output of my preamp that is sending a nasty signal of some kind? I look forward to any help as I am quite upset. I dread sending my Bryston across the country...or the preamp for that matter. Or what? thanks, Jim
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