Anyone auditioned Pass Labs XP-30 preamp?

I think you answered your own question -- the problem must lie not in the preamp but how it was set up.

All of Pass' preamps require 12 - 24 hours of on time before they reach their normal operating temperature for the class A sound and they are not meant to be powered off (hence no switch.) Was your unit adequately warmed up before your audition?

Great review -- thanks for sharing.

Based on what I've read and my communications with the folks at Pass, it seems that sonically the XP-30 benefits from a new volume control that is very quiet and a massive power supply that makes it quite immune to power line noise and anomalies. Overall, the sound is supposed to be extremely detailed and resolving without sounding harsh.

Back in 2010 I visited Pass' booth at CES. At that time, they hadn't decided if they would top out their line at XP-20. The two-piece XP-20 already edged out the older, 3-piece X0.2 in performance and it wasn't clear if the addition of a third box would bring meaningful benefit. It's interesting that they did finally find a way to improve things. This was how they described the differences to me:

- the XP-15 edged out the Xono slightly; the XP-25 was better than the XP-15 by quite a large margin

- the XP-20 was slighly better than the X0.2; the XP-10 is a touch less resolving than either and had slightly less articulate bass, but it did have a very pleasing, musical balance that some people preferred

Hi Peter: I don't have personal experience with these linestages as I haven't listened to the XP-30 and I don't do vinyl, but this is what Pass told me about the XP-30. It was originally a prototype for their inhouse needs of chaining amplifiers with different gains to a single preamp. (They didn't say what for, but it might have to do with the new Xs amps.) As a byproduct of this design requirement, they managed to get the noise to an extremely low level; the noise of the new volume control even exceeds the resolution of their test instruments. In order to ensure that this level of performance is always available (and not masked by distortions / noise brought about by fluctuations in AC quality), they gave the XP-30 a massive power supply and extensive voltage regulation that would have been considered very overengineered just a few years ago.

FWIW there is a new review,

http://www.dagogo.com/View-Article.asp?hArticle=1060

The reviewer compares the XP-30 to the MBL 6010d which is arguably the best preamp I have ever heard.

I'm curious how the XP-30 (or XP-20) compares with the ARC Anniversary Reference (or the Ref 5). When I upgrade my X0.2, these are the linestages I'll look at based on fit with the rest of my system. Another preamp that I'm very interested in is the Esoteric C-03. Heard it at a few audio shows and was quite impressed with it.