Jafant...
My first Pass design amplifier was a First Watt M2 which up until then struck me as one of the most colorless amps I'd owned. Rated at 40 watts per channel into my 4ohm Thiels I assumed having more power, the headroom at least, was a wiser route to head in, especially since I've not let up on searching for a pair of 3.6's or above. There's a pair of 7's listed here for $2200 - but the seller cannot ship!
Within two or three weeks I returned the M2 for a full credit toward the X150.5 which was then $2300, methinks. The one I just got was $2700 with a 1 year warranty and the seller covered the shipping. I've mentioned before how idiotic it was of me to sell off my first, and that won't happen again. I find Thiel and Pass to be extraordinarily well suited for one another.
The M2 introduced me to Mr. Pass's approach to amplification architecture, and I have to add that I find his candor, philosophy, and attitude very refreshing. I've also found that I like buying products from a guy with his name on the box. My appreciation for Thiel at first was the product only, but as I grew more familiar with his story I appreciate these speakers all the more. As I've mentioned before they've absolutely become my reference point for loudspeakers.
Anyway, I believe I had an ARC LS2b preamp at that time along with a cheap Pro-Ject phono preamp. (I like ARC, too.). The difference between the M2 and the X150.5? Sonically speaking I could not discern a difference; all that clean, uncolored, presence was on equal terms for me. Were I to downsize - heaven forbid - I would not hesitate to buy another First Watt amp.
I've been eyeballing a Pass X.01 pre just listed here for $1800, but I can't entirely justify it because a.) I don't really need it and b.) I really like my B. A. T. preamp. And c.) the holidays are here and my girlfriend might kill me if I buy another piece of equipment.
Just for the absolute hell of it I just bought a Khozmo passive preamp and have been listening to it for a couple of days now. I had a passive back in '14 and I should'a kept that. Anyway, thinking how articulate my Thiels and Pass combine to be, I figgered why not toss a passive in the mix? The results?
Wow - with some caveats I'm still wrapping my ears around, but my thinking was well rewarded. Everything's a little "brighter" altogether, but the separation and clarity are what I was hoping for. Heck, $300 for a little s'perimenting is a bargain in this hobby ain't it?
Good reads folks, keep 'em coming.
