To supplement Ff116's comment. There's quite a bit of difference between the X.5 and the non .5 version of the Pass amps. I own the X350.5. Prior to purchasing it, I had the opportunity to hear it compare side-by-side with X350 at a friend's house as he was debating which one to buy. The preamp was the ARC Ref 2 Mk I. All four of us at the shoot-out all were a bit surprised how lean and solid-state like the X350 sounded. The X350.5 exhibited more of what you would expect from Pass with the warm and tube-like midrange and excellent control on both ends. The bass control was just superb. We all thought the difference justifies much more than just an ".5" upgrade status.
I am running mine with an ARC LS-25 Mk I (with Reference level mod by GNSC).
FrankC
I am running mine with an ARC LS-25 Mk I (with Reference level mod by GNSC).
FrankC