PassX-250 vs PassX-350

What is your speaker's efficiency? The 350 will run in class A louder than the 250, and that will affect your perception.

(disclaimer: I sell pass gear)

I would definitely go with the X350. If power is any question you want to get that amp. It jumps from the 'will power most speakers' X250 to the 'Will power ANYTHING' X350.

I have matched the 350 up with a Bat preamp (vk-5i) and found it was quite a nice combination. Since the Pass gear is so transparent it lets the character of the feeding source come out more.

(disclaimer: I sell Pass Labs gear)

BTW- I am using Martin Logan Ascents.

Krelldog-

I use an X-250 with Martin Logan Aerius i's, along with a Pass X-3 for rears/center. They replaced Bryston 4B-ST & 5B-ST's. The Pass amps are sonically miles ahead of the Brystons with these speakers, even though the similar specs do not suggest that they would be. I considered the X-5 or an X-150/X-3 combo before buying the X-250 & X-3, and talked to Pass Labs about the speakers I was using. They knew the Aerius well, and definitely recommended going up to at least the 250 for the front mains.

With ML's, you want current - lots of it. I don't think you could ever over-amp these things. But I find the 250 can handle driving these speakers that drop to 1.2ohms at 20khz quite well.

Would the 350 do it even better? - Probably - just as RangerAudio suggests. I just could not justify running $2300 speakers with a $9000 amp, nor could I afford it. Besides, I bought my pristine 250 used (right here on the 'goN!) for a great price. I have no regrets or desire to upgrade above it now.

FINAL NOTE : Just yesterday I replaced my Aerius with Talon Raven 2002 speakers with Khorus-X/2 CMRC crossover upgrades. So far, the synergy of this Pass amps/Shunyata Lyra cables/Talon speakers combo is proving to be quite magical and dynamically powerful. These are not, of course, electrostatic speakers, so they are an easier load on the amp.

Hope that helps,
Bob Houser