Two Pass Labs Preamps: X0.2 vs. X1

Introduction

One of Sinter Klaus' elves, dressed in brown, recently dropped off my end-of-the-year audio reward. Although I haven't always been good this year, I have been very good at not getting caught.;)


Figure 1. I like the way Pass Labs puts a couple of large stickers on their
shipping boxes announcing the box contents along with serial numbers.:rolleyes:

I actually intended to get an X0.2 last year, but I took the advice of my dealer and got the X1 because, according to him, the X0.2 was twice the money [footnote 1] but just a little bit better. He said that he had listened extensively to the X1 and X0.2 and that the X0.2 was only somewhat better-- lower noise, better imaging, slightly better bass and treble. Nevertheless, he uses an X0.2 in his personal audio system.

The dealer advised that it would be better to get the X1 and live with it for a while in order to better gauge if the upgrade was worth the price. If I decided to upgrade at a later date, I would receive a generous trade-in allowance.

Another fellow gave this candid comment when asked if there was a substantial difference between the X1 and the X0.2:

“It's a matter of opinion. The 0.2 is better, but it does cost twice as much, and it does not sound twice as good.”—Nelson Pass

A well known audio reviewer expressed similar thoughts after comparing the X1 to the X0.2's predecessor, the X0:

"I did not find significant sonic differences between the X0 – which I believe is true state of the art – and the X1. The X0 is just a bit quieter; you can listen a bit deeper into the sound floor; and the deep bass may be just a bit better. In a truly quiet room, the X0 fades a touch more into the background, and may also be a little faster and more detailed, particularly on really complex and demanding musical material.

Both the X1 and X0 had the kind of air and natural harmonic sweetness you normally hear from tube preamps and from a handful of transistor designs. Both also had the kind of dynamic life I associate more with tubes."—Anthony Cordesman, February/March 2001 issue of The Absolute Sound

Mr. Cordesman obviously believed the X0 was worth the extra money because he used one in one of his reference systems for several years. He subsequently upgraded to the X0.2 when it became available.:)

Competent, informed counsel is a useful thing to have. Personal experience is even better. After living with the X1 for over a year, I decided it was time to take a personal look at the X0.2. I was thinking that a monoblock preamp would be a great complement to my monoblock power amps...and I was right!


Figure 2. My X0.2 preamp made it through the UPS system without
being abused or pilfered. It's true: Miracles still happen.


Figure 3. The X0.2 offers more input/output facilities than the X1.
I only plan to use two of the inputs and one of the outputs.

The Sound

I expected that the X0.2's triple chassis design, with separate chassis for the left and right channel circuitry, would provide better imaging and soundstaging performance. I was not disapppointed. In fact, I was thrilled. To summarize, the X0.2 provided the following performance improvements over the X1:

1. A little more detail throughout, particularly in the bass. On some songs I noticed little details that I hadn't heard before. If I had to quantify things, I would say the treble and midrange is 10% better (more detailed) and the bass is 25% better with more impact in addition to more detail.

2. I had more of a sense of bass sounds vibrating through my listening chair and body with the X0.2.

3. Piano notes were more percussive with more overtones and natural decay.

4. Stringed instruments had more overtones, weight, and fluidity.

5. While there was not a 2X price/performance correlation for the X0.2's improvements in detail and clarity over the X1, I did realize a spectacular improvement in soundstage 3-dimensionality and weight. I also gained a little more soundstage width and depth. The width of the soundstage increased about a foot (sometimes more, depending on the recording) on each side and the depth increased about three feet. Also, the weight and solidity of images at the outer edges and rear of the soundstage increased dramatically. This difference in soundstage rendering was even more apparent when listening to my analog source. If I had different and/or smaller speakers and listening preferences, I probably would not have been as impressed with the X0.2's spatial rendering qualities. I believe that I received my 2X money's worth in the X0.2's soundstaging and imaging properties alone, therefore I am very happy.:D:D:D:D:D

My euphoria over the X0.2 notwithstanding, I was still very reluctant to trade in my X1, even though I had no immediate use for it. I let it sit on my dining room table for a few days while I stared at it and tried to rationalize keeping it. Eventually, it was shipped back to the dealer. My self-imposed rule against hoarding gear sometimes extracts a heavy emotional toll. However, it didn't make sense to have that much cash tied up in my audio closet when it could be put to better use in my cable upgrade fund [footnote 2].:)

Conclusion

My two channel upgrade project, which began in 2003, is nearing completion [footnote 3]. I have a few more cables to evaluate and I have to construct an AI-1 non-common ground interface so that I can evaluate a couple of power amps I'm interested in. I have already requested a quote from Avel-Lindberg for a custom toroidal transformer with the specifications given by Matthew Polk. I expect to have the AI-1 project completed by the end of this month. With regard to cables and amps, I am not so sure that I will be able to find "better" for (what I consider to be) a reasonable amount of money. I know I can always find something "different". One of the power amps I am considering, the Pass Labs X600.5, does some things better than the JC 1's, but it also comes with some inconveniences and performance tradeoffs...but that is a subject for another thread.



Figure 4. The X0.2 made it home in time for the holidays. Such Good Sound.

Footnotes

[1] MSRP of the X0.2 is $10,000. MSRP of the X1 is $5995. Mint condition used units typically sell for 50% of MSRP.

[2] Cable evaluations are an ongoing thing with me. Sort of like a hobby within a hobby.:)

[3] Product research and evaluation began in January of 2003. Hardware acquisition began in July of 2006.