Pass Labs XA-25 vs XA-30.8 amplifier

I purchased efficient speakers so I had flexibility with my amp purchase.

I have the XA25 running through a Khozmo preamp into the Crites speakers, which are Klipsch clones.  The amp is very pleasant and neutral.  Very good bass. Build quality superb. I will not be selling it. The 30.8 will be warmer but a even beefier amp, it puts out over 100 Class AB. It also weighs 90 pounds which influenced my decision.  If some talks you out of Pass there is Ayre, Luxman, Sugden and Coda which all have generous Class A output.

I had the XA-25 and the X150.8 in my home at the same time for a demo. Reno hi-fi, which is gone now, but was an authorized Pass Labs dealer, graciously loaned both to me. I listened to them primarily on Martin Logan Impression 11s, and also on a pair of KEF ls50s. The XA-25 was very clean, "water clear" is the term that kept coming to my mind. The X150.8 was bigger, more fleshed out, maybe a little warmer, and more engaging on the electrostatics. Maybe because the Martin Logan's can be a little dry and overly analytical. In any case, for me it wasn't even a contest, The humble X 150.8 just sounded better and more musical. I brought the XA-25 back to Reno hi-fi and kept the X150.8. I still consider it to be the best sounding amp I ever had on the Martin Logans. And I had a lot of amps on those speakers. The folks at Reno hi fi told me they weren't surprised, and that the XA-25 was so well reviewed that a lot of customers were disappointed and several ultimately traded it in for something from the 8 series. That of course is just one man's experience (mine).

Cheers,

Ron

When I was upgrading from my Nakamichi PA-7AII (A Nelson Pass Threshold design) I was convinced I wanted dual mono's. I tried the PS Audio M700's and The Schiit Tyr (both dual mono), but while they did help with the soundstage width and depth, they clipped. Turns out my 30+ year old power hungry Accoustat 1+1 will occasionally draw a 0.5 Ohm which was not a problem for the Nak. 

I contacted Nelson Pass and sought his guidance. He directed me to the XA-25. If there was not enough power, then the 30.8 was the next option, but he felt the sonic capabilities of the XA-25 were better and would be a great match for the Acoustats. I was concerned there would not be enough power because the Accoustats have an efficiency of 82 or 83 db depending on which source if referenced. I do help the efficiency with an active SPL Crossover allowing the dual Rythmik F12SE subs handle the bass. The XA-25 handles the speakers amazingly well. The only upgrade I would make would be if a dual mono version of the XA-25 became available. Nelson's person system has a pair of XA-25 as dual monos.

Try the XA-25. If you don't like it, then go for the 30.8.

30.8 is an amazing amp with efficient speakers