Hi, I am a Bryston Limeted rookie living in Sweden, but also proud owner of some great Bryston products - BP26+MPS-2, 4BSST and BDA-1. I got the amplifiers 2009 and they are from 2005, so I am the second owner. I have the 4B connected to a pair of Pioneer S1-EX speaker with an exceptional result.
But even the sun has its spots and about 10 days ago the left channel suddenly went silent at power up. I did some trouble shooting and could eventually find the problem was in the BP26. More specifically in the left front switch named Source/Tape. I have never used it in my 8 years and it has constantly been in Source position. When I wiggled the switch from side to side I got all combination of results, sound in left channel, in right channel, no channel or both channels. It did not vary so much when operating the switch in its normal direction, i.e. up-down, but carefully wiggeling it side ways gave different results all the time. My conclusion is the internal switch contacts are oxidised/dirty most likely. They should not have had time to get mechanically worn due to the extreme rare use.
I have contacted my Bryston rep in Sweden and it will be fixed under the 20 year warrenty as soon as Bryston have sent new switch to the rep.
The BP26 have a similar front switch marked Mono/Stereo and both these switches are in series of each other and with the input selector in the internal amplification circuit paths. But while the Source/Tape and Stereo/Mono switches are probably not used that often by normal users, while the input selector is used a lot in comparison. So it is probably wise to use your "unused switches" to reduce the probablility of oxidisation/dirt to cause problem like these.
The BP26 also include two low signal relays in the signal paths, one for mute and one for inverted polarity. These relays are of IP67 class (sealed) and use gold for internal contact points and should thus be much more unlikely to oxidise or get dirty. The mute relay is also active at every power up while the polarity relay is not used more then occationally by normal user. But it should probably not be subject to the switch problem.
I have posted this topic once before just after registrating at AudioCircle but the post never showed up. Now I have introduced myself at AudioCircle and could see the introduction post as public, so I hope this post will be displayed this time.
Anders
