Pass labs X250.5 vs Jeff Rowland Model 10, or 201

Goone, both the 250.5 and 350.5 are great sounding amps, however, the best sounding single chassis amp in the .5 series is the 350.5 by a significant degree.

Not just more power, but a qualitative shift towards "musicality" without losing any extension on the top or bottom, details, and dynamics. The 350.5 is only slightly bettered by the mono-block 600.5's, but they cost almost another $9000.00.

I believe the 350.5 is both the sonic and cost "gem" of the Pass Labs .5 series. It replaced the highly regarded Edge NL-10 in my system, which cost almost $3000.00 more but was out performed by the Pass Labs 350.5.

I just bought a Pass X 350.5 . I have 100 hours on it .
I would definitly say it has a very natural midrange. Not harsh in any way. Sort of tube like. Center stage is very deep.
Not sure on how many hours it takes of playing time to reach its full potential though. Any ideas ?

Thanks, Jwon.
Did you hear an improvement in sound from 100-hours to 600 hours ?
At 100 hours I still think the bass needs a little refining.
I am using the Pass Amp with my APL 3910 direct. No Preamp.

It took about 250 hours for the unit to mature. Base did improve and the depth of the sound stage grew larger. The general warmth and musicality stayed consistant after about the 100 hour point. By the way, I'm driving Avalon Ascents which are not easy speakers to drive in the base department. The 350.5, however, does a wonderful job of surprising audiophile friends who heard these speakers driven by various high powered tube gear. (VAC, BAT,
ARC ) Even some of my tubes or die friends have had a hard time finding fault with this power amp.
Jeff