I own a pair and love them. I upgraded the tubes, the best improvement came from switching to 845M tubes from "supertnt" web site. My wife says she hears a high pithed ringing noise when I use these amps, but I can't hear it. According to Ming Su, the distributor, he only imported four pair to the U.S. goto www.rowlandhifi.com to get my contact info if you like.
