Suggestions for power amps

I have the Pass X25. Outstanding amp for the price. Very reliable. Warm to neutral sound with lots of reserve. Works best when really warm. One of the last pieces I would upgrade in my system, if at all.

I have an ATI 6000, 2 channel AMP. Purchased from Sound Approach, I believe in Virginia. Outstanding AMP, IMO $3795 New     7 year warranty, Look up info,reviews, you will be impressed. Mine is paired with Fritz carbon SE Mk2 and is GREAT, complimented with a SVS SB3000 sub in a small room, about 13x14'   I listen only to Rock and Roll, Pink Floyd, Zeppelin, Ps Great place to do business with too    Service is everything to me. Robert TN  ps Great DAC also, Meitner  Be advised AMP weighs almost 100lbs.

Why aren't you looking at Buckeye Purifis? Seems like an easy choice. 

   + 1 for adding sub(s). Then roll in an amp. I run low power tubes to Zu’s , but rotate a 50 wpc SS amp. I back the subs off a tiny bit when going to SS. BTW , I loaned some tubes to a fellow for his pre. He has the same amp as you and loves it. Happy Hunting , Mike B. Oh, and + 1 for the Pass. 

The Benchmark ABH is an excellent amplifier; I used it with my Fyne Audio F-702 speakers and got wonderful sound.  I sought a bit more power, however, and am now using two mono bloc Odyssey Kismet power amplifiers, which put out about 200 watts each, and the sound is wonderful.  Excellent imaging, great tonal qualities for the instruments, and dead silent background.