Mark and I too exchanged email's on the differences between XA 60.5 and the XA 30.5 and he conveyed to me they were a worthy upgrade if you can justify the cost and have the floor space.
Also, to enforce Kent's advise, when Stereophile (May 2009) recently reviewed the XA 30.5, the writer was surprised Mr. Pass sent the XA 30.5 rather then the more powerful monoblocks. The review was very positive for the XA 30.5, but the writer felt he would not buy the XA 30.5 himself with the Wilson Sophia II's he owns due to needing more power.
Speakers the reviewer used were NHT Super Zero's and Wilson Sophia 2's.
If you have not read the magazine, here are some snippets.
"Nelson's amplifiers, whether they were his earlier designs for Threshold or his later ones for Pass Labs, have always been on the my wish list, so I was delighted when the opportunity arose to review one of the latest Pass amps. I was a little surprised, however, at Nelson Pass's suggestion that I audition the XA 30.5. I'd expected a pair of X1000.5 monoblocks perhaps,, or maybe the XA 200.5s, fi he thought they'd do the job....but a nominally 30 WPC stereo amp? I double checked, and yes, he did know what speakers and other amplifers I was using, ansd yes, he was aware of the sort of gear I usually reviewed. Despite all that-actually, because of all that-he reiterated his preference that I audition the little guy."
"To be fair, I was running the XA 30.5 well out of it's comfort zone. Nelson Pass explained to me that the front panel meter, which indicates the amount of current being drawn from the wall, "Should sit somewhere in the middle" and "won't move if you running in class-A." During most of my listening sessions, the meter would bounce between the middle and, say, the three-quarters point of its range. When I was listening to and for large dynamic swings, the meter would frequently be pegged. This didn't seem to bother Pass when we discussed it though he did say, "Hmmmmm......so you're pulling a lot of juice." Well maybe if I'd gotten those XA 200.5 monoblocks.."
"Plus in todays high-end audio world, the XA 30.5 is a steal. Compared to what else is out there, a price of $5,500 is low for an amplifier of this quality. No, I probably wouldn't buy one, but only because I think that a larger, more expensive Pass Labs model would work better in my system. Absolutely, positively, and enthusiastically recommended."
