Soundstage,imaging,and musical detail. Also seems a lot more powerful then its 150w rating

none

In the last two weeks I had the chance to demo in house a Bryston 4B-ST and the Pass Labs X150. I currently own Classe amps CA-200 & CAV-75.
I must say that all of these amps are excellent performers,and if you chose to purchase any of these amps you could not go wrong.
I liked the build quality of the Classe the best,and it seemed like it was probably the best built for the money.
As far as sound quality.... I purchased the Pass Labs. It was by a very narrow margin over the Classe.

current system:
Muse Model 5 cd transport
Elite DVL-91 DVD/LD player
Lexicon MC-1 preamp/processor
Pass Labs X150 amp (planning on purchasing the X5)
Classe CA-200 & CAV-75 amps
Dunlavy SC-IV main speakers
Dunlavy SC-I/AV surrounds
REL Stadium III subwoofer
Better Cables
API Powerwedge

Similar Products Used:

owned Classe CA-200/CAV-75,Acurus A150,Sony TA-N55ES. In home demo'd Bryston 4B-ST. Store demo's multiple amps (Krell,Sim Audio,Mark Levinson,Plinius,Proceed).

Detail/sound staging/resolution and build quality and beaty are all 10's!!!

Bass get's 9/10 compared to other Pure Class A amps I've heard, but still great!...Otherwise no weaknesses for $$$!

Now let me start out by saying that I haven't yet purchased this amp for my own little self as of just yet (I'm working on it though!). But as a dealer for the Pass, I've had it hooked up to a variety of different speaker, all to good effect!
The Pass is extremely neutral, clear and detailed!...Sound staging is glorious! The Midrange is just right, with pleanty of body and the bass is just about as good as I've heard for the power/money! I've heared other pure class A opperation amps that have more tight fisted bass weight and authority, but only marginally! My CODA amp, for example has a tad more beef in the bass, as do some of the Krell stuff I've tried, but only marginally watt per watt!
I'm not 100% sure, but I think alot of the strong bass performance, especially at low volumes, is due largely to the Pure class A opperation !? At any rate, to keep this shourt, I've played this amp, and it's bigger sibbling (x350) on Speakers such as Thiels, Maggies, Martin Logans, and Celestions, and I think this amp is as good as anything your likely to come across with adequate output power! Ofcourse there are some small watt amps out there (50w or less) that you could nit pick about being better in one area or another. But for shear output of power and audiophile purity, I don't think your likely to beat the Pass for the $$$
System matching, ofcourse, will always play the bigges role though...You might get buy with lesser amps with easier to drive speakrs!

Similar Products Used:

CODA System 100 Pure Class A amp.
CLASSE CA300

Serious Hi-current : Range , clarity , definition , openess
etc.etc.

Sorry everyone : BUTT UGLY . Rear binding posts .

I have had this new X150 on loan from my hi-fi buddy for approx. 3 mos. now , as he has been trying out my new Plinius MK3 100 on his S.F. Amator 1's. To start I must say I love the Plinius & will most likely keep it , as a trade for this Pass is possible.
The amp powers my pair of B&W P 5's
& will power whatever pair of new speakers I replace the 5's with.(the 5's are going no where). BUT I gots to say this Pass has the "juice"; this is hi current big time & it stretches the B&W's both top & bottom much farther than the Plinius . It's clarity , resolution , & openess are unsurpassed .+ Strike 2 Plinius . But I cannot live with the pass because I cannot stand it;s looks ! Please no responces to the obvious idiocy of this statement , I know this full well. But it is hideious . I thought I may be able to overcome this until the capper for me. I fail to grasp the logic in building a world class amp such as the pass & including only 2 speaker posts ! That put me over the edge . 2 posts on a $4000 amp . Also the build quality is excellent but not compared to the Plinius . Which is truely a Tank , with all kinds of posts for diff.wireing configs. & also the ability of switching on the fly from A to AB . A 10 yr. transferable warrenty etc.
If the Pass was in black & had a couple of
sets of posts on the back my buddy wouldn't be getting it back.

Similar Products Used:

McIntosh ; Plinius . etc.

Supreme clarity and articulation, floats a huge soundstage that effortlessly fills the room, cleanest amp I have ever heard without the sterility of some high-tech SS designs (think: famous Silicon Valley amp company), wonderful company with endlessly great customer support; beautiful builkd quality and industrial design

This amp is not lush. It will not "warm up" your sound like a CJ, a single-endede triode, or even the Pass Aleph series; the plastic speaker binding post covers are a humorless joke on an amp of this price ($4000) and quality. No, I did NOT use a wrench or apply 100 foot pounds of torque, and yes, one came off in my hand after 3-4 cable swaps. Ho ho, not amusing.

This unit is best described as pristine. There is a sense of utter clarity and openness on All types of music, yet without harshness. Mind you,l currently have it on Quad 63 US Monitors, a very unforgiving transducer. Contrary to what others have remarked, I find the bass extraordinary in quality, though larger and more demanding speakers would be required to test the issue down to the bottom ocrave. High frequencies are the purest yet in my experience, but one realizes this without having one's attention called to it and in the absence of artificial etching or detail.

The soundstage is to die for, and I say this having used some pretty tweaking tube and SS stereo and mono set-ups. I am fortunate to have a room approximately 28-30 feet long (I always forget the exact measurement: another senior moment), 17 feet wide and with a ceiling sloping to 16 feet high on one side. I have about 12-16 feet of free space BEHIND the speakers, set them up 9+ feet apart (centerline to centerline), and sit 9+ feet back, more or less in equilateral triagle but sometimes farther back. What emerges at, to the sides and behind the speaker is, well, a concert hall.

Here is a big point that never occurred to me previously, even with the phenomenal Aleph 2 monos (one of the best amps ever made, period). There is an uncanny sense of detail and inner detail that is incorporated into and along with soundstage and timbral information, not at all as if these were separate attributes that had to be combined to equal a good whole. It's spooky. All the necessary audiophile golly gee whiz things are here, but they always occur only in the context of a whole, or Gestalt, if you will. I cannot overstate the subjective effect of this. Until you have experienced it, it may be fifficult to fully appreciate. Suffice it to say that it is no longer necesary to give up one thing to get another or, for example, to put up with timbre at the expense of detail, dynamics at the expense of liquidity, etc. This amp gets out of the way with a vengance.

Quiteness: I have opened the system up all the way (I'm not kidding) without music playing and put my ear to the speaker. Remember, these are Quad 63s, and whether you like that speaker or not, they leave nowhere to run and no where to hide (Roger Modjeski once said: the most neraly perfect speaker in design and execution in the history of hi fi). The result: I'm getting older sure, but I'm not deraf yet. ZERO hum or noise heard by me.

Caveats: The amp lacks the warm, sweet richness of the Aleph series. It is more neutral, detailed, and cleaner, but the Alephs do have a single-ended magic that is hard to beat. If you have large, hybrid electrostats that need help sounding like music (you know who) or merciless horns, stick with the Aleph series. If your taste runs to the Hales Transcendance Series (a superb match, I would think), SoundLab, or the new larger Quad 989s, the X-Series is a must audition.

I cannot comment fairly on macrodynamics, as this is not a great strength of the Quads. Microdynamics may be equal or superior to the Aleph 2 (which was simply stunning on the 63s in this resprect--the "finger bounce of piano notes" for example), but I have changed rooms and the Quads are now on their own in a much larger space with far less acoutical support. Comparisons, therefore are difficult.

You cannot do better than to deal with this company. They are honest, friendly, endlessly supportivbe via phone and email, like to receive chocolate, and even have a sense of humor (I know, I couldn't believe it eithert at first, humor and down to earthness in the high-end--who woulda thunk it). There is no longer any reason, ANY reason, to buy tweaky-breaky multi-thousand dollar esoteric designs, thermionic or otherwise, that will be out of fashion, out of service, or requiring expensive updates the next year. Ever notice how long Pass products stay in the line. Ever hear of a "Pass Mark 2?" You can feel good about dealing with this outfit and safe with your investment. In fairness, Music Reference (Modjeski), Vandersteen and a number of others deserve equal praise for product longevity and design integrity.

Summarizing: brilliant designs (Nelson Pass and Wayne Colburn) from a stand-out company of stand-up guys. Actually, one or more of those guys are women, which gives me even greater faith. Women are smarter.

Only negative: I love mono blocks and dealers pressure manufacturers for easier to sell stereo units. I have begged, pleaded and whined to the Pass folks to put out a "baby X600", perhaps in a X150 or X250 size chassis, 150-300 watts, zero feedback and a price point reachable by more of us. Meanwhile, dump the X350: do you REALLY want to lift and move a 150 pound amp the size of a VW? Secret but true: Nelson hates stereo amps, loves monos and emphasizes the desirability of monoblocks sited near speakers with "short, thick cables." Only commercial pressures, I feel, account for the X250 and X350. If you share this view, add your voice to mine in petitionoing the company to bring this level of performance to a mono configuration at a morer realistic price. Companies need to hear from their consumer base when considering product launch. Let them know you care.

To Nelson, Wayne, Peter, Joe, Desmond and all the rest: thank you for a great product. But really, those speaker connectors are an abomination on a $4000 amp. I mean, Puhleeeze!

Rated 4 stars only because there are better: the X600, etc. Be reasonable, if the X600 is a 5-star reference, can the X150 be equal to it at 1/4 the price? The product ratings on this web site suffer from runaway grade inflation.

My system:
Play/Transport: Sony X779ES & Marantz CD63 SE
DAC: Pass Labs D1 (does digital get any better?)
(w/Analog volume control)
Amp: X150; Adcom GFA 535 (dual mono original)
Speaker: Quad ESL 63 USA Monitor
Interconnects: Silver Audio Hyacinth balanced, 3 meter
Cables: Analysis Plus Oval 9

Replacement speaker on order shortly: narrowed down to Quad ESL 989 and Sound Lab Millennium 2 (comments, folks?)

Coming soon: return to analog

I apologize for the verbosity. It's a measure of the enjoyment I am currently getting from music, in no small way due to these components. Thanks for listening.

Similar Products Used:

Rwoland Model 7 monos, Counterpoint SA 220, Beard tube monos, ARC 150 (the original from the old days), BEL, Parasound, Adcom, Spectral, Quicksilver (8417 monos, V4 monos, MX 190), Music Reference RM 9 MK. I & Mk. II, Pass Aleph 2 & 5, etc.

ALL

None (yet)

Very good sounded amp. I would say this is a 'solid state' amp w/ vacuum tubes amp capabilities. The mid and high are just like vacuum tube amp.......but with more solid and deep bass.
Audiotion this amp if you choose to buy 100-150 watt amp. Mr. Nelson Pass surely knows how to build amps ::))

I give 5 stars to this amp.....

See original review, below.

as above

Perhaps it is overkill to submit a follow-up after the lengthy review posted only last night (typos and all). I feel one or two things must be added, however, to do justice to this product.

I noticed that I failed to comment on midrange, dimensionality and a few other "audiophile" considerations. The mids are utterly open, free of grain and transparent. I cannot discern a character, unless you prefer an artificially warm and lush sound that glamorizes the presentation. You won't get that here. One frequently heard cliche is that a piece qualifies as a "reviewer's tool." The X150 goes in that direction. Neither cool and lean nor warm and lush, it offers (to my ears) characterless presentation. Perhaps the best word is "seamless". Another cliche, true, but apt in this case. From the bass through the mids and into the highs, there is an effortless unity of sound, an absence of discontinuities, a coherent oneness.

Dimensionality of images and specificity of placement are, it appears so far, as good as the source allows. As mentioned in the previous posting, an integral compnent of the amp's performance that facilitates this is a difficult-to-describe, "all at the same time" presentation of inner detail, tonality or timbre, dimensionality and dynamics. As is often said of fine speakers, the amp speaks with one voice. Until you have experienced this, it may be difficult to appreciate via the words of another. At first, other amps (I would even include the Aleph series) will impress more profoundly because of an ear-catching, magical midrange, dimensionality, transparency, microdynamics or other particular quality. Then, and this has become a huge revelation for me, you listen THROUGH a component that does not so blatantly impress (like platinum blond hair or huge muscles) but rather reveals its virtues as a function of your involvement in listening to great music. You don't have to think about it. You just keep playing disc after disc, and not just audiophile wierdo stuff, but all forms of real music. (Do you have the latest, state of the art recording of East Timor, left-handed shoe-string tying noises? Wow! What fun.)

No component is perfect, and individual tastes are, in my opinion, perfectly acceptable and even necessary in choosing a musically rewarding system. There are beautiful sounding amplifiers of disparate sonic persuasions. Feel free to choose one, and don't apologize if it makes you happy. But for me, Pass is on to something, and it is my kind of something. If you want an amp to paint a Monet on top of your Mozart, this is not the ticket for you. Conversely, if you want your components to get out of the way, nothing more and nothing less, the X-series may be for you. Unless your system is overly lean, grainy or sizzly, this should be worth an audition. But be aware that everything will come through.

It is remarkable to me that Pass markets this amp in a "downscale" manner as part of their Home Theatre series. I can only wonder what the X600 achieves with its all-out design, dual mono chassis, separate grounds, zero feedback, etc.

As for the X150, if you own a yacht, a second condo off Central Park for the occasional visit to the city, an Lexus LS 400 to drive while your Jaguar is in the shop (again) and his and hers matching Rolex watches, get the X600. If you have a slightly more modest lifestyle, this may be the amp for you. The best amp in the world? No. The best amp, overall, that I have heard anywhere near the price? Absolutely.

This amplifier frees music.

Now, let's get some trickle-down going and get Pass to make "baby X600s" in a wattage and price range the rest of us can afford.

Similar Products Used:

Krell, Rowland, Spectral, Music Reference (RM9 I & II), ARC, Beard, Counterpoint, PS Audio, Adcom, Parasound, Quicksilver (MX 190, 8417, V4 monos, balanced), Audio Research, BEL, Aleph 5 and Aleph 2 monos