Responding to twoleftears' post: I had a hum in my AX550, still under warranty. It wasn't that loud, but not normal. I sent it in to the new USA distributor (Luxman USA). They did a fantastic job repairing the unit - great service from my perspective. It took about a month because they had to order a new transformer from Japan. But it gives some confidence in their service for something made outside the U.S., in my opinion.
As for sound, I was paring with Tannoy Turnberry. After reading this thread, I think it is funny (as Erik stated), that people have a hard time describing the sound, because I would too. The first thing that comes to mind is that it 'did nothing wrong', and possibly a bit dry (in a good way) sounding. Usually when people say it did nothing wrong (or 'committed no sins of commission'), you see this in reviews of lower priced equipment, and I always take it as an indicator of decent sounding gear that is also not going to win any awards. In contrast, in this case I would say it was the opposite for the Luxman, it does just about everything right, but otherwise just doesn't standout in any overt way. I loved it - only reason I moved on from mine was I did not consider the heat it put out (the 550 is class 'A') when I purchased it. Overall, I would say they have great detail, midrange, bass, presentation, musical flow... I have owned McIntosh Integrated (MA6900) though with different speakers and a different room and years apart (so take with grain of salt), so hard to compare. But I would say both have a different house sound (having owned other Mac gear in the past); the McIntosh more inner-midrange detail and fleshing out, perhaps better (or more bass); whereas the Luxman is top to bottom clear & neutral. For me the Luxman is more musical.
