Pass Labs amps questions


SO i started looking into Pass brand amps.  My room is carpeted movie theater of rectangular shape, 18 wide x 26 ft deep.  I'm currently running Audio Research 5SE into Mark Levinson 331 (100 watt RMS SS at 8ohms) then Dynaudio Confidence C4 speakers.  Although I love the sound this gives me, i feel it just doesn't have enough oomph!  For example, in order to sound "right" when i listen to the Eagles Hell Freezes Over DVD, volume is at level 60 on the 5SE.  Im not detecting any clipping at all nor does the Levinson get too warm.  I don't think its straining at all but not sure how to tell.  Its old and i just want to try and get a different or maybe see if i can get a better sound.  I am wondering what the audioafficianados out there would recommend or provide more info on with regards to the Pass Labs line up.  I am specifically wanting a pair of Class A mono blocks.  What falls in my budget is a pair of the XA200.5's on the Agon site here now VS a New/Demo X350.8 demo from Reno Hifi.   Would the X350.8 hold an advantage over the 200 monos with its additional 300 watts of power (C4s are 4 ohms)? I remember needing to double the power in order to move the SPL 3 db???.   If this were correct and given my room size, would this added power benefit my system? All in all would you prefer used pure class A less power or brand new class AB higher power for about the same price?  I'll sit and *listen* for your knowledgeable replies.  Thanks in advance.
chenglo1
A few years ago I ran C4s with 250.5 and loved it,Ive heard the .8 amp...either way your going to enjoy,I guess it just depends on your budget .
 
I agree. My Pass amps were definitely at a higher level than Pass preamps I've owned. But you don't give an alternative. If not Pass or ARC, what preamps do you like with Pass amps? 

I like tubes somewhere in the system.  I use an Ayon Pre with my X150.8. The Ayon has 6H30 tubes and I am not going to change any time soon.
i would agree that pass labs preamps are not quite as good as the amps...i think it's time for an update of sorts...perhaps wayne (he designs the preamps, not nelson) is working on that right now...