I started as a fan of the Aleph series and when they released the X-series, I thought that the resolution had greatly increased, but the amp lost some of the magic of the previous series amps. The XA series combines both and it is done quite well.
If you can get away with the power of the XA30.5, I strongly recommend it over the X150.5.
X-.5 (dot 5) series of amps is much improved over the original X series IMO. X-.5 amps sound much more like XA amps than the original X.
Is the power output between the X150.5 and the XA30.5 very different?
Yes, 150 watts versus 30, but the XA.5 seem to be conservatively rated, at least they sound that way. You should be ok with the lower power with speakers 89db or higher, less then that you are probably pushing it.
My speakers are 92 db and 4 Ohms, but they have lots of drivers 2-10", 2-7", 2-3" and a tweeter (Montana XP, plus I have a large room (35 x 25 x 10 foot ceiling). I was just wondering if the additional price of the XA30.5 used was mainly because of it being a newer model, or is it also better in performance?
Completely different animal, XA.5 is Class A and the the X150.5 is A/B - 99% of people will tell you the XA.5 is the far better amps in the Pass product line. I think you would have no problem with the XA30.5 power, especially with a 40hm load. Call Pass or Reno HiFi, they will give it to you straight as to whether the match is suitable.
X-150.5 is 150W / 8 Ohm and XA-30.5 puts down 130W / 8 Ohm as tested by Stereophile.
Wow! Wonder why the spec it at 30 watts, they did say in an understated manner that it was "conservatively" rated, but that is REAL conservative. Is that a continuous power measurement or peak?
The x150.5 actually puts out 250 + watts in 8 ohms continous.
All Pass amps are pretty conservatively rated watts wise.
OP, if you do a search for XA.5 you will find a few threads that discuss the differences between the Class A and A/B Pass amps. If money were no consideration, they only time I think folks would opt for the A/B would be to bi-amplify and used as a bass amplifier where the differences Class A provides for really come through, otherwise, used full range....well, read the threads.
I have not hard the 150.5 but can tell you that the XA30.5 is a great amp. Whether it is a good match for your speakers is hard to say. I had the XA 30.5 with very efficient 8 ohm speakers and it was a great match. I went to a 4 ohm speaker with 2 10 inch woofers, 2 7 inch midrange, and a tweeter, and it was not as good a match for those speakers. Also, you have a pretty good size room. Of course, the only way to know is to try the different amps and see what you hear. Stephen
I'm currently using the Pass XA30.5, and have to say the amp drives the loudspeakers I've paired with it thus far quite well.
Koestner: I'm currently using the eps2: little brother to your speaker, with the same rated sensitivity. I emailed with both Pass and Reno HiFi about this amp choice, and both strongly recommended the XA30.5. But my room has a considerably smaller footprint than yours, and I listen to mostly small scale music, mostly fairly quietly (65-75db, peaks south of 85). I expect both variables could affect your choice. But as others said, I'd contact Pass and Revo: helpful folks.
John (Jdoris) I listen to lot's of different stuff, and a bit louder than your avg. level. I think I listen at around 85 with peaks to 95. What is your opinion on those levels, and I gather you are happy with the sound?
Hi again. Sorry, should have been clear: I have not yet purchased the XA30.5; it's likely I will as circumstances permit, but I'm still shopping. So I was reporting the advice of the manufacturer/vendor, not listening impressions.
Btw, my current amp is the Odyssey Stratos dual mono (180wpc) -- more comparable to the x150.5, I'd guess. Sounds good, but way more power than I need on the eps2s. But your room is bigger than mine, and your listening levels considerably higher.
If 95db peaks at what distance - 1 meter measurments? If so, you should need about 1.8 watts for that - but I suspect that is not the distance of your measurement. If you want to know if it is enough power Pass or Reno will certainly be able to tell you - they are not going to BS you, they are the folks I would trust for issues related to power,loudness, and drive. As for quality of sound, I, and many others, think the Class A Pass gear (XA.5) is in the top ranks of what SS is capable of.