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The Amp Quits Agin -- Am I Missing Something?

I have a 4b-ST I left on for about 4 hours Friday night only to return to find that one of the channels had died in my absence. While I was gone, the system was on, but not being used. I haven't really investigated at all to guess what may be wrong, other than to determine that that CD player and the preamp are still working fine. The left channel on the Bryston seems to be working fine, as does my left speaker. The right channel, however, appears to be completely dead (even the left LED is dead) and I have no idea what may or may not have happened to my left speaker. I'd love to not have to send the amp back to the shop (again, it was there in February for a muting switch) and am hoping that I might have missed something obvious. Any thouhgts? Thanks.
mezmo
jcaudio's avatar
jcaudio
237 posts
 
Doesn't sound like anything obvious. Have you checked to see if any fuses have blown. Sometimes there will be some inside the amp for each channel. I'm not sure regarding this particular amp. That is where I would start though. If all ok there I think it is time to call Bryston. Hopefully it will be a fuse though. I have had similar situations which 9-10 times was a fuse I overlooked. Good luck
gregm
3,021 posts
 
Whatever it is, it doesn't seem like an external enemy -- otherwise both amp channels would be on hols. EXCEPT if the main ground is wired onto the right channel & it blew due to trash entering the system from the mains while you were away. I hope Jc has it right, otherwise you may have an output transistor that's kicked the bucket.
Not very helpful -- we need Sean & Co here. Keep a stiff upper lip!
mezmo OP
516 posts
 
Ugh, as I suspected. My hope is that the channels are on independant fuses and that one of them went on me -- here's to hoping for the simple solution. Haven't checked them yet, but that's going to be the first (and likely the last) place I look when I start digging. And to add insult to injury, I just had $200 in new CDs delivered about 5 minutes ago. Darn lousey timing. (PS as for my apparent inability to tell my right from my left in the original post, what can I say? We'll keep it simple: on side work, other side no work).
rbirke
144 posts
 
on the plus side, you couldn't ask for better service than you'll get from bryston if something is wrong. my former amp was a 4b and it did indeed have a problem. shipped and fixed in a jiffy, and all i had to pay was one way shipping to vermont.
sdcampbell
2,136 posts
 
I own a Bryston 4B-ST, and have a couple of suggestions for you:
1. Check the switch on the rear panel for the "Bridged/Individual" mode to be sure that you have not accidentally set it to "bridged" (which would cause the amp to operate in only one channel).
2. Check the fuses (under the panel next to the power cord connection).
3. If neither of the two steps above result in a "fix", then send an E-mail to James Tanner at Bryston. Go to Bryston's home page (www.bryston.ca), and at the bottom of the home page there is a link for technical questions. Tanner is terrific about providing fast answers to E-mails he receives.

If your amp does have an actual electrical problem, you can remove the non-functioning amplifier module for the dead channel and send only that module to Bryston for replacement or repair. Bryston will sometimes send you the replacement immediately while the module from your amp is in transit to Bryston's U.S. repair facility (in Vermont, as I recall).
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