Hello,
I just purchased a 4B cubed amp. It sounds awesome but has one issue that is annoying me. I'm getting a low level buzz from the left speaker. This buzz is audible from up to about 3 feet from the tweeter. My speakers are about 88 dB sensitivity. I've sent a message to Bryston and am waiting for reply Monday.
I've done a bunch of troubleshooting and the results are as follows:
- buzz occurs for both balanced and unbalanced
buzz increases/decreases with 23dB/29dB gain setting
cheater plugs on amp and/or preamp did not help
with no interconnects or interconnects and no preamp, no buzz
with preamp only, and no inputs to it, buzz
with passive stereo volume control (no inputs to it), buzz
with unbalanced inputs shorted, no buzz
with unbalanced inputs shorted, and LR shorted to each other, buzz
So based on this, anytime the LR inputs share a common ground, the buzz appears. I really want to solve this problem because the amp really sounds great. I also have both a 3Bsst and 4Bsst which are dead quiet so it really should be fixable.
