Sophia II's and Pass Labs etc

I have directly compared the XA30.5 to the XA100.5 on my Sophia II's. The XA30.5 sometimes runs out of steam, whereas the XA100.5s do not. The XA100.5s are better in every way than the XA30.5, it's not just a power thing. You get fuller, more stable imaging, better delineation, more articulation across the entire frequency and a much larger soundfield horizontally, vertically and dimensionally.

All that being said, I chose the XA30.5 for my Sophia IIs as my SS amp ( I use both tubes and SS amplification for the speakers depending on my mood ). At 1/3rd the price of XA100.5 mono blocks, the XA30.5 delivers maybe 85% of the sonics. I also found the XA30.5 to be a little sweeter with more "character" than the larger and more neutral monos. This sweetness created a more INVOLVING presentation, for me, with the Wilsons which certainly benefit from amplification that fully fleshes out harmonics. Th XA30.5 is also almost as transparent and textured as the XA100.5s, so detail freaks need not fret.

These amps heat up small rooms quite quickly, FYI. The monos produce about 3x as much heat as the stereo XA30.5 and suck just as much energy too.

Boils down to budget and what you're willing to spend to get that last ounce of performance. The XA30.5 is a great match with the Sophia IIs, and the XA100.5 are even better. I liked the price and involving performance of the XA30.5, so that's what I chose. The Sophia's are relatively efficient, so the extra wattage of the XA100.5s aren't needed for higher SPL, but mainly for CONTROL which equates to a better performing system (speakers and amps).

Give Pass Labs a call, Kent is extrodinarly helpful and quite frank about his opinions. For my situation, he heartily recommended the XA30.5 and discouraged the XA60.5s. When asked about the XA100.5s for my set up, he said it would be a bit better, but the XA30.5 really makes the best sense unless you just have to spend $15k +.

Hope this helps. I started a thread "Wilson Sophia2s demand better than AYRE V5xe, so" where I make comments about the XA30.5, FYI...

Oh, and I listened to the XP-20 which is a remarkable preamp, but it's not the most transparent or 3D, depth producing preamp compared to the best out there. I thought my Ayre K1xe was more transparent and textured than the XP-20. I liked the "sonic signature" of the Pass amps better than pre, and when put together, ALMOST too much of a good thing, but that's just me and I'm picky, so listen for yourself...

Spatine,

Kent at Pass Labs mentioned that on my speakers, the XA30.5 and XA60.5 would perform quite similarly with the main difference in power and current. Kent made the point that the XA60.5s would outperform the XA30.5 at high volumes (100db+), while at normal listening levels there would be little difference. Kent mentioned that the XA60.5 are basically monoblock versions of the XA30.5 and were produced for people who desire monoblocks. He strongly thought the XA30.5 would be more than adequate for the Sophia II's, and the XA60.5 would be overkill and not worth the extra money (on my speakers). I should make the point again that those with slightly less efficient speakers would benefit from the XA60.5s.

Kent recommended the XA100.5s over the XA30.5, noting that in addition to power and current delivery, there are other improvements that put these monoblocks in another league sonically and when played at precisely the same volume (important point). At the same volume, sound output, I noticed specific differences between the XA30.5 and XA100.5 which I mentioned in my previous post. He did not elaborate much beyond that, but suffice to say he felt that for the Sophia II's the XA30.5 is a perfect match, the XA60.5s would be a sideways step, and the XA100.5s are the sweetspot in the XA.5 line (he prefered these to the XA160.5 and the XA200.5), so if I had the urge for Pass Lab's best, go for the XA100.5s, but the XA30.5 makes the most sense.

Having said that, I have not compared the XA30.5 to the XA60.5s and I have been told by Mark at Reno HiFi that he does not share Kent's assertion of the XA30.5 compared to the XA60.5s, even on Wilson Sophias. He feels that there is a significant enough sonic improvement between the two that justifies the price, even with efficient speakers. Also, I think I read someplace on the boards that one XA30.5 user found the amp to be inadequate with his Wilson Sophias, so as usual it depends on your situation, system and listening environment.

For the original poster's benefit:

I would recommend the XA100.5, but not the XP20. Although I voiced my opinion clearly for the XA30.5 with the Sophia II's, I think compared to the rest of your system, the XA100.5s would be the best fit. I think you would appreciate the difference between an XA30.5 and the mono XA100.5s and you would be willing to pay for the improvements. In my situation, the XA30.5 fit the bill just fine both financially and sonically (and it allowed me to purchase a tube amp to swap out during winter months or when the mood was right). The XP20 is very good, but you really should pair the XA.5 series with a tube preamp as it will only add to and enhance the sonic purity of timbers/harmonics you get from the XA.5 series.

Hope this helps.