Rotel RA-01 balance problems

I've previously posted this on the HFC forums, so apologies to anyone who's seen this before.

I recently bought a Rotel RA-01, which was great - apart from one, slight, problem. The right hand channel was noticeably louder than the left. Specific left hand sounds come out fine, it's just stuff that's on the left & right that's off center. I tried changing sources (problem persisted) and swapping the speakers around (thereby making the left hand speaker louder). Confused, I took the unit back to Sevenoaks who promptly swapped it for a new sealed unit. The problem is, this new unit suffers the same problem as the last (though, interestingly, it didn't seem to in the store...).

I've already got a few other people to have a listen (they've noticed the left is louder if I invert the channels, even when I didn't tell them). I measured the voltage on both outputs using a multimeter: the left channel rates at 31.4mV silent and 32.5mV with a simple constant sound; the right channel rates at 34.6mV and 35.7mV. Is this 3.2mV difference a symptom of a problem with the potentiometer, or is this perfectly normal?

I assume the balance control would degrade the sound, so that's only a last resort Wink

Rotel RA-01
Sony CDP-XE570 (to be changed, very soon)
Denon TU-260LII
Monitor Audio B1's
Qunex II I/C
Chord Carnival Silver Plus S/C

N.B. Both speakers are single wired and in phase. When I swapped channels I swapped them at the amp end (i.e. left hand cable/speaker was louder on the right hand channel). The speaker cable has been changed from SA to some chord carnival silver. I've also tried both speaker outputs

 

Next, you need to swap the CD L+R outputs at the CD end, or does it also do it on your Denon tuner? If it does, maybe it's the volume pot..

 

Yeah it does the same on my tuner