Pass X vs XA amps sound quality in class A range

Thanks for your replies, I have the X250 driving a pair of B&W N802, room size is 32ft by 42ft by 20ft height, at their widest, a fairly large room and open to one side to dining room. Driving the speakers w/o the current meter moving (in class A?), it sounds mighty fine but when driven harder, there is a gradual hardening of the sound and loss of air. I am curious as my upgrade path should lead to either the X600.5 or the XA160.5. If they both sound similarly excellent at 50W/ch in class A, I would go with the X600.5 just to safe for those parties that I tend to crank it up.

The X don't sound as good as XA.5s given that the XA.5 provides sufficient power, they are not both "similarly excellent". So, if 160 watts is enough power for your speakers, room, and loudness levels you listen at, I don't think there is much doubt as to which of your two options is preferable.

I think Pubul57 is right. I suspect that the X600.5 and the XA160.5 are unlikely to sound the same, even at lower volumes. My understanding is that the circuitry designs of the two amps have significant differences, and that those differences are audible, even when both amps are operating in Class A. Certainly I can say that my X250.5 and XA30.5 didn't sound exactly the same, even when both amps were operating in Class A.

Your room is quite large, and you mentioned a tendency to listen at loud levels. So it is not a clear cut decision, IMO. It would ideal if you could audition the XA160.5's in your system, to see if they have enough power for your loud listening sessions. If it were me, and I could not audition the amps, I would take a chance on the XA160.5's. I have heard the XA100.5's, and to me, they sounded absolutely glorious. FWIW.

Hopefully other Pass owners with more experience than I have will offer their advice.

Bryon

Much thanks again for all comments, I think you have answered my questions, that they sound different even at low power levels.

I owned the XA160 and switched to the XA100.5 and now the XA160.5. I have a difficult speaker load in a small room and don't usually listen beyond peaks of about 95dB with mostly classical music. There is no comparison between the XA and the XA.5. The latter is much better at all volume levels particularly in the handling of and control over lower frequencies. Sense of ease/flow, dynamics and air/space are also better. The XA.5 current delivery and doubling of power as impedance halves are big improvements over the XA model.

These are glorious amps in my system, but they are quite expensive. You should try to arrange a demo in your very large room to see how they sound with your speakers in your system to be sure before you buy.

You could also try asking Kent at Pass Labs or contacting Mark at Reno HIFI if you don't have a local Pass dealer. I have found both gentlemen to be very helpful answering questions.

You can read a more detailed review of my impressions of Pass Class A amps on my Audiogon review of the XA100.5. I am admittedly quite biased as I have owned many of these amps.