Soren,
50 ohms is great. What brand and how long are your ic's to the Pass? Is the needle on the Pass moving when you are experiencing the flab? My 30.5 had more articulate bass on my Maggie 3.6 than my previous McIntosh 1000 watt monoblocks (as long as the needle wasn't moving). Going to Pass's 100.5 was a noticable improvement in bass. I haven't heard the 60.5. Twice the power would only give you 3db more loudness BUT that plus each channel having its own power supply would give your more control. Maybe not enough for your taste or speakers.
XA power is expensive. Have you thought of trying one of the X.5 series?
