Pass Labs X250

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TomDac

former MLO owner/operator
Joined
Dec 27, 2004
Messages
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Location
Rancho Mirage, California
Amp Manufacturer: Pass Labs
Model: X250
Manufacturer's Suggested Retail Price: $6,000
Used market average price: $2,500
Basic Specs (watts, etc.): 250W into 8 Ohms. 500W into 4 Ohms
What ML speakers are you driving with this amp: reQuests

You can read many reviews of this amplifier online which will include technical specs, graphs, sine wave charts, etc. If you’re interested in any of the Pass Labs amplifiers, read those reviews before reading this review and before auditioning a Pass Labs amp.

This is my first foray into high end amplification. I should state that I believe auditioning amplifiers in an audio store will provide you with information on how the amplifier looks, how it is built, which lights get lit, how it can connect to your system, etc. What it sounds like at the store will not necessarily be any indication of how it will sound when you get it home. If you can, get a demo unit to take home – one that is broken in. This is the only way you’ll know what you’re getting into.

I should also state that I feel that amplifiers are like automobiles. As soon as you take a new one home from the dealer, they depreciate. Buying a used amplifier is like buying a used car – if you know the history of it, feel comfortable with the owner and see how he takes care of his other audio gear, you can feel confident in purchasing his used equipment. The Pass Labs X250 is a discontinued model, so finding a store that had one still in stock was not an option. It originally retailed for $6,000 – which is way more than I could justify spending on an amplifier, but used ones appear on Audiogon for $2500 or thereabouts and that’s where I found this one.

With all that being said, I purchased this X250 amplifier without ever hearing one in my system. I did this based on recommendations by several key people on the MLC site including jtwrace and Gordon Gray. I also did this based on the Nelson Pass history and the high regard and reputation his designs have earned over the years as well as what it says in the X250 user manual:

“The X circuit was designed to be quite happy driving electrostatic and other speakers”

The manual seems like it was written by Nelson himself, and probably was.

The amplifier is a monster. It’s 100 pounds and built like a tank. It is definitely something you don’t want to have to move that often. The big blue meter is nice. It’s nice to see something that will give you an indication of what the amp is doing. Here’s what the meter on the X250 does:

The meter shows bias. So while the amplifiers operates in Class A the meter will be stationary, as it draws more current and enters AB the meter will move.

This replaced a Carver TFM-35X amplifier that was driving my requests and I thought that the Carver did a pretty good job. Boy, was I ever wrong.

Right away I noticed the channel separation of this amplifier is so distinctly better that I may need to do some re-positioning of my speakers. Bass sounds much more controlled and richer. The sound is more airy, refined and open and I can hear more “layers” of instruments.

Here’s my Critical Listening playlist. These are all tracks that really show off the system and sounded exceptional prior to the X250. These are the tracks I use to show off my system to friends listening for the first time.

1. Straighten up and Fly Right from Round Midnight with Nelson Riddle and his Orchestra (2 of 2) by Linda Ronstadt / Nelson Riddle & His Orchestra
2. Blue Light, Red Light (Someone's There) from Blue Light, Red Light by Harry Connick, Jr.
3. Take Five from Time Out by The Dave Brubeck Quartet
4. Your Starter For from Blue Moves by Elton John
5. Funeral for a Friend (Love Lies Bleeding) from Goodbye Yellow Brick Road by Elton John
6. Flight Response from Days of the New II by Days of the New
7. State Of Independence from The Friends Of Mr. Cairo by Jon & Vangelis
8. The Friends Of Mr Cairo from The Friends Of Mr. Cairo by Jon & Vangelis
9. Gold Dust Woman from Rumours [Expanded] by Fleetwood Mac
10. Show Me from The Lexicon Of Love by ABC
11. Tied Up from Flag by Yello
12. Cantaloop from Starbucks Blue Note Blend by Us3
13. Flamenco.A. Go. Go. from Flamenco A Go-Go by Steve Stevens
14. The Downtown from Days of the New by Days of the New
15. No Such Thing from Room for Squares by John Mayer
16. Tempted from Singles 45's and Under by Squeeze
17. Freedom from Listen Without Prejudice, Vol. 1 by George Michael
18. Last Plane Out from Toy Matinee: Special Edition by Toy Matinee
19. To The End Of The Earth from Everybody's Changing by Keane
20. The Frog Prince from Under the Iron Sea by Keane
21. Cowboy Star from Somewhere I've Never Travelled by Ambrosia
22. Don't Go from Upstairs at Eric's by Yaz
23. Sirius from Eye In The Sky by The Alan Parsons Project
24. No Excuses from Jar of Flies by Alice In Chains
25. Badman's Song from The Seeds of Love by Tears for Fears
26. Standing on the Corner of the Third World from The Seeds of Love by Tears for Fears
27. Evil Empire from Blaze of Glory by Joe Jackson
28. Sultans of Swing from Dire Straits by Dire Straits
29. Opaline from Opaline by Dishwalla
30. Yours for the Taking from Libertine by Gene 1
31. We Close Our Eyes from Aces and Kings: The Best of Go West by Go West
32. Pullin' Back the Reins from Absolute Torch and Twang by k.d. lang
33. All Through the Night from She’s So Unusual by Cyndi Lauper
34. Borrowed Heaven from Borrowed Heaven by The Corrs


I won’t go into all of the details while listening to each of these tracks but here a few noteworthy comments:

Straighten Up and Fly Right by Linda Ronstadt w/Nelson Riddle is just an exceptional track that really pushes the limits of any amplifier. The Carver would clip like crazy and send the Denon into meltdown mode (protection circuit – shut off) at high volume passages of this track.

On Cyndi Lauper’s “She’s So Unusual” SACD on track 6 “All Through The Night”, the opening keyboard notes are super crisp and clear and in your face like I’ve never experienced before. At 1:17 into this song, there is a “swooshing” of high octave rings from left to right that I could hear before, but now it’s in the forefront of the soundstage.

Elton John’s “Funeral For a Friend” is one of those tracks that I have been using for critical listening for years as it has incredible dynamics and huge “WOW factor” when playing at high volume levels. The X250 controlled this so beautifully. The sustained organ notes were very strong.

On many of these tracks, I could hear the singer breathing or the air moving thru the instrument or the fingers sliding over the frets.

The Corrs “Borrowed Heaven” sounded like the lead singer was standing right in front of me. The ending of all her words were more pronounced and I could hear her breathing. This was another jaw dropping “WOW.. I’ve never heard THAT before!!” moment.

After about 5 hours of very critical listening at pretty good volume levels, the amp was warm to the touch on the top, the cooling fins and even on the thick metal face.

Conclusion
This is by far the most significant addition to my system EVER and the best $2500 I’ve ever spent. It controls the reQuests very easily and with authority. To me, it didn’t sound “warm” or “tubey” at all.. It just sounded very neutral. Again, I haven’t had much exposure to different types of amps, so maybe I just don’t know what “warm” or “tubey” sounds like. :D

I also noticed that when using my Squeezebox, the settings of the DBX 4BX dynamic range expander had to be lowered, which tells me the amp is able to reproduce alot more range than the Carver could.

I have no other high end amplifiers to compare the X250 to. I’m sure there are others that will sound equally good. I highly recommend getting a high end amplifier like the X250. You won't know what you're missing until you do!

Thanks Nelson!
 

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Great review Tom! Have fun "rediscovering" your entire music collection again! It's amazing what difference a well-designed amp makes.
 
Tom, great write-up. Your enthusiasm for your upgrade has gotten me even closer to pulling the trigger on a decent 2 ch. system. Thanks alot! :)

PS....the unplugged version of "No Excuses" is excellent as well....the whol AIC Unplugged album is very well recorded for a live recording....especially an MTV one. And if you like the Days of the New stuff, you should listen to Tantric if you havent already. Similar style...obviously with all the members of Days of the New minus the lead singer...although the singer for Tantric sounds similar. Its good sounding stuff. Enjoy!!
 
Thank you Tom!

Tom,

I appreciate you writing a review of this wonderful hunk of metal. I am also humbled by your kind comments. Thank you Webmaster. I told Jason I'd chime in once you wrote a review. So here it is.

I previously had a Classe Audio CA150 and was frankly quite happy with it for a long time. Had the amp for nine years and it powered the Aerius, the SL3, and most recently, the Summit.

Given the fact that I was listening to nine year old SS technology, I started getting the dreaded upgrade itch and tried a VTL ST 150 tube amp. Although I liked what I heard, it just wasn't my cup of tea. Enter Jason and his absolute, take no prisoners enthusiam for Pass Labs and, as they say, the rest is history.

I find that your observations are, from my experience, spot on. Clarity, quickness, neutrality, and great control.

There was an immediate increase in the mid bass energy coming through the panels. This had a substantial effect on increasing the "foundation" of the sonic picture.

The one thing that struck me the most was the ability to hear "into" the recording venue. An example is the six CD set of Keith Jarrett at the Blue Note / The Complete Recordings. I have listened to these discs so much so that I am intimately familiar with the sound of the instruments as well as the sound of the club. The Pass Labs (PL) amp immediately revealed the sonic signature of the recording venue to a degree that I had never heard before. The acoustic bass took on a character that sounded so much more lifelike but not in an analytical way. Keith's "hooting" sounds were much better rendered and sounded as if they were "part" (read connected) to the piano sound versus a recording artifact coming from a different place in the overall soundstage.

A couple of nights ago, I played the Holly Cole / Temptations CD. I've always read that the sonics on this disc were spectacular and I have certainly enjoyed this disc over the years. With the PL in the system, this disc took on an entirely different character. Voice imaging much better rendered, with the piano and acoustic bass filling the spaces so one had the feeling that you were listening to a trio in "one" sonic space versus three separate instruments.

Another obvious attribute is the overall smoothness of the top end. I'm not a techy type but I gather this has something to do with the type of transistors used in the PL versus those used in the Levinsons or Krells. All the detail one would want with the sound of "brass" clearly coming from the cymbals versus the metallic "swish" I used to hear with the Classe. The top is, if my memory serves me correctly, quite similar to the VTL.

And then there's the sense that the PL has headroom to spare. I think many of us, including me, have this anxiety that the amp is going to give up the ghost and go into clipping when one is playing extremely dynamic material. Not a problem with the PL and my Summits. One has the sense of "ultimate" control regardless of the dynamic swings.

And then there's the voices. I listen to alot of female vocalists and am very sensitive to sibilance (read fuzz) around the voice. Again, the PL is stellar in this regard. Voices are not like what I heard on the VTL (rounded, smooth in a very euphonic, seductive manner) but well delineated with just enough warmth for my tastes.

Like you, I've had little personal experience with other "high end" amps. Having said that, I frankly can't imagine what a kilobuck amp would do much better than what the PL does. All I can say is that each time I play familiar material or new music, I have the impression that I am so much closer to the music than I've ever been before. And for me as well and, I trust others who are part of this crazy, wonderful ML Club, I think that's what it's all about.

If anyone is looking for an SS amp that is powerful, musical, and non fatiguing, I would advise you all to seriously consider an audition. And if you decide to buy, you can blame Jason, just like I did.

GG ;)
 
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Yeah, I have the unplugged CD as well as Tantric's first CD, which was just OK IMO.

:D

Tom, great write-up. Your enthusiasm for your upgrade has gotten me even closer to pulling the trigger on a decent 2 ch. system. Thanks alot! :)

PS....the unplugged version of "No Excuses" is excellent as well....the whol AIC Unplugged album is very well recorded for a live recording....especially an MTV one. And if you like the Days of the New stuff, you should listen to Tantric if you havent already. Similar style...obviously with all the members of Days of the New minus the lead singer...although the singer for Tantric sounds similar. Its good sounding stuff. Enjoy!!
 
Tom,

That new amp looks awesome!! Knowing that it sounds as good as it does with no coloration is just too cool. I have been curious about Pass Labs amplifiers, but I have never had the pleasure of listening to them. I'm really happy with my Sunfire CG Signature and how it sounds, but now after reading your review on the X250, I may decide to get one :) Also great choice in music selections ;) Congratulations on your excellent purchase!

Enjoy!
 
Great Review!

Tom,

I get a real perspective when reading your review of the Pass Labs x250 of just how the amp performs.
I have read and re-read various reviews and Pass Labs owners manuals over the past year. Your review / recommendation as well as Gordon Gray and jtwrace are very uplifting to me as you guys actually own ML speaker systems. :D

Thanks again. :D
 
seeing recent articles at CES - seems like I have seen this amp run in a mono-block config? So - how cool would it look to have one sitting next to each speaker? It would give a more even blue glow in the room I would think and would be more aesthetically pleasing???:devil:
 
Awesome review, Tom. I really enjoyed reading it. You'll make a believer out of even the most die-hard Plinius fan (read: Joey v). Just out of curiosity, how often do you see the meter needle move indicating that the amp is going into AB bias?
 
At normal volume levels, the needle doesn't budge. With the volume cranked up, it swings all over the place in time with the music.
 
Excellent write up Tom!

Everytime I read your review and comments, I get the image that you sit back exhale and press the play button and enjoy that wonderful new addition to your system. I'm still a little ways off from buying my 250 but hopefully soon I'll be able to join your level of bliss.

Thanks for the terrific follow up reviews.

Goes without saying, happy listening! Enjoy!

Sam
 
Tom,

Most excellent write up! Even I caught myself looking at Pass Labs gear on the 'gon.

Joey ;)
 
Yeah, I have the unplugged CD as well as Tantric's first CD, which was just OK IMO.

:D



Side note:
I saw an episode of intervention and the lead singer of days of the new is heavily addicted to drugs and living with his mom. Its sad he had all of that talent and is hustling his mom for $200 to get rock.
 
Side note:
I saw an episode of intervention and the lead singer of days of the new is heavily addicted to drugs and living with his mom. Its sad he had all of that talent and is hustling his mom for $200 to get rock.

Yeah - that episode is a couple years old... His name is Travis Meeks and it was a sad situation.. According to the DOTN website, Travis is playing again on his own, in small venues in the midwest. I think he's from Louisville.

I saw them as DOTN right after their first CD dropped at a very small place and he is talented beyond belief.

That's a great show, btw. After watching a couple of seasons of it, they all are the same.... My sister watches it with her two pre-teens... A good look at what drugs can do to you.
 
Apparently Primare designers previously worked under Nelson Pass

Hello folks!
Check out the Primare Audio web site: Primare engineer Mike Bladelius formerly worked for Pass Labs and Nelson Pass's old company Thershold. A few days ago I tried out a Primare I30 Integrated Amp with my Aeons. Lately I have been trying to find a surround sound amp for my Aeons, Depth and Cinema (don't have rear speakers yet, might get Frescos). I currently have a pair of Sonic Frontiers SFM-75 Mk II mono blocs, they have a nice touch of warm to vocals, but I find they lack power and midrange control, even at moderate volumes. I tried the Arcam AVR 350 which I found to be very detailed and clean, but a bit too bright and dry. Next was the Primare; as the store did not have any Primare surround sound equipment in stock they suggested I try the I30 Integrated. To make a long story short, my listening impressions are similar to TomDac's Pass X250 impresisons. Phenomenal bass power, control and fullness, high and mids are very open and detailed, dynamics and punch to die for. Midrange shows a touch of warmth on female vocals. I used several CDs but one that stood out was Carolyn Dawn Johnson's "Room with a View". The first track's vocals had an almost "reach out and touch" quality to them. I am hoping to audition a Primare SPA21 surround amp in the next month. I'll post a review..........
Cheers, Chris
 
My search for sonic nirvana ended with the Pass X250. It's still in my system and I am still loving it and have absolutely NO desire to change it out. I'm using a Pass X5 for the rest of my channels and that is working wonderfully also.

Since I'm using the X250 to drive a pair of Summits, everything is just great. The CLS's are a bit harder to drive, so I'll be interested in hearing your thoughts once you've had some time with it.

If I were in your shoes, and the X250 wasn't enough, I'd get another X250 and use them as monos. That would be AWESOME.
 
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My search for sonic nirvana ended with the Pass X250. It's still in my system and I am still loving it and have absolutely NO desire to change it out. I'm using a Pass X5 for the rest of my channels and that is working wonderfully also.

Since I'm using the X250 to drive a pair of Summits, everything is just great. The CLS's are a bit harder to drive, so I'll be interested in hearing your thoughts once you've had some time with it.

If I were in your shoes, and the X250 wasn't enough, I'd get another X250 and use them as monos. That would be AWESOME.

Tom,

You responded to my invisible post...:ROFL::ROFL::ROFL:
 

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