I have a Marantz 6003 setup with Wharfedale diamond 10.1 speakers connected to my PC via a Behringer BCA2000 audio interface. I have noticed that there is a bias towards the right side. If I switch the audio interface to mono, the sound moves more central, but in stereo mode it is definitely more pronounced on the right side. I have the amp in source direct mode, so the balance control should not be affecting it, although it's set to the centre anyway. I have also compared the sound via headphones, plugged into the amp, which still seems to favour the right side, although less pronounced, and into the audio interface, which seems more balanced. This suggest to me that the source is ok, so it must be the amp that is producing the imbalance. Is it possible/likely that the channels on the amp are giving a mismatched output? Are there any settings I can check before contacting Richer Sounds for a repair/replacement? I have toyed with speaker placement but the fact that the staging moves more central in mono mode suggests that is not the issue, as well as the fact that I experience a similar effect with the headphones. This is my first proper Hi Fi and the improved soundstage was one of the effects I was most looking forward to, so this is really bugging me! I would appreciate any advice.