In reply to:
Yes, the mk1 has some low-level background noise, but it's pretty quiet. It's so quiet as to be very hard to find on the mk2.
Good:) Honestly, that's the main reason I sold my Mk1 - the background noise was driving me nuts; I'm a bit more sensitive to these kinds of things then most people are.. ( i can't even stand a ticking alarm clock:) ) I had gotten the noise down to an acceptable level on my mk1, but didn't really have my amps turned up as much as I'd have liked...
-mark
...proud to have owned one of the first Mark I units