Pass labs X600


I would like to know, what amp from another manufacturer is comparable to the Quality and potencial of the Pass X600 regardles of price. What amp can be consider to be as good as the X600. I'm in the market for a pair of monoblocks, but seems that I won't be able to find any X600 any time soon, so I need another options? Also what make Pass labs X600 so heavy? is it worth the weight?Any help will be apreciated before I make a decision.

Are you Guys gona let me down?
Since you are getting no responses, I will give you a couple to try out, that are found relatively often on Audiogon.

Either the Levinson 33's or the 33H's.
Both have been very well reviewed.

They don't have the power of the Pass X600's, but they certainly have the credentials as being sonically good as a solid state amp can be. (Do you need that much power by the way? What are you driving?)

Also, VTL makes some pretty nice tube amps that have similar power to the Pass X600's. The Reference 750's are what Albert Porter is now using to good effect with his Soundlabs, and my friend is using the MB-450's with his Eidolons. (The MB-450's sound great, and will not clip, even when driving his speakers to very loud listening levels with very large symphonic pieces of music!)

Just a couple of possibilities.

Good Luck in your search!
I will drive Dalis MS5. nominal impedance is 4 ohms
Pass is the best because they are heavy, hot, sharp, and emit that blue light that is universally attractive to the male species. Krell also has the blue light, but there is more of it with Pass, so that makes them better. The Pass are selling at a little over $22 per pound or $11 per watt, so that is pretty good.

Seriously, the Pass is a great deal, and they are always offered on audiogon or ebay. Although some people may say that the x600 did not quite do it for them, I've yet to hear anyone bad mouth the things. In the end, you probably just need to either listen to the stuff yourself, or roll the dice and order something. It's doubtful that people can help you at this level.

I don't think weight is everything ... my old Pioneer SX1280 receiver weighed a "ton". Maybe I should bring it back up from the basement ?

But seriously, getting recommendations for a good SS amp in this price range may be difficult. You will excite some of the tube vs. SS people and are liable to get marked differences of opinion. In this price range, some will suggest you look at Edge NL amps, Gryphon, Dartzeel, before the tube guys put them in their place.
The X600's are great amps, their sound is fast, timbrically correct, a bit on the dry side but depends on your gear and, yes, a real bargain on the used market... They sound not like a 600 watts monster with enflated muscles but like a superfast 100 watts with incredible power reserve, I'm in love with my X600...
What is your Guys opinion on the Plinius SA102 or maybe SA250?
Gryphon antileon signature stereo or mono.Flemming (owner of Gryphon)jokes that weight is the most important spec.Why ? Because TRUE class A amps get REALLY hot and require big heavy heat sinks.Does class A matter? YES! I switched from a very expensive Chord AB amp after I nearly blew it up.Chord claims that it was universally stable under all loads.The Chord was a great amp.Way better than all the usuall suspects.When I switched to the Gryphon Iwas floored by the low level detail and the limitless power.This despite a much lower nominal 8 ohm output rating. As it turns out the Gryphon can put out up to 5000 watts/channel as the ohms drop. Now thats universaly stable! If your amps going to put out this much classA its got to be big and heavy to dissapate the heat.
Any other opinion?
A very well broken-in pair of Parasound Halo JC-1 mono-block amps. I love mine!
I have a friend from another state who actually sold his Pass X-600 amps after listening to the JC-1's. He wound up buying the JC-1's!
Hey Guys ,what Daltonlanny said can be possible?
I know a guy who did just that. I bought his X600 and later sold it for an Acoustics Reality eAR, only to be sold for H2O monos, my present amps. Each change worked wonders.
Yes, I would check into Henry Ho's H20 monos also.
I have heard some great reports about them!
Daltonlanny, do I have your Adcom? I lost all my mail.
Yes, you do have the Adcom GFP-750 that I sold you awhile back.
I really think Muralman1 is on to something good with the H20's.
His speakers are unthinkably demanding in the greatest sense of being and show everything that's in front of them, no doubt. I have original literature on them too !! (I happen to like them a lot)
The H20's seem to be the begining of a new era, they have unlimited power reserves, run cool as a cucumber and are way more dependable.
I'd put a tubed output cd player in front of them, like a Jolida JD-100 or Audio Aero Prima, then you'd be talking music.
(I'm sure your Dalis would benefit, also a good tube preamp would not be out of the question)
I can not find any info on this amps. There is not one for sale on audiogon
We there are also the FPB series of amps from Krell that, like the Pass, are also Class A circuits.
I would suggest that you save your money and consider a Pass Aleph series amp. If you need a lot of power, you
can wait for used Aleph 1.2's to come up for sale on Audiogon. These monoblocks are 200 watt/channel of pure class A, unlike the X600 which switches over to class AB after a few watts. This should be enough power for all but the most demanding applications. A fully class A amp
cannot easily be built to the wattages of the X600 (too
many problems with heat dissipation), but amps fully biased as Class A, such as the Alpeh, tend to sound like much bigger amps than their wattage ratings indicate. If you are interested in musicality, neutrality as well as a natural and detailed sound, you would be very hard-pressed to find nearly any solid state amps which will give you as much. They are not nearly as "pretty" as those X600s, they will get much hotter. but their sweetness,
musicality and lack of electronic signature is unsurpassed, even by the X600, which, although the electronic signature is slight, is still there. And they are cheaper. You'll just have to wait for a pair to come available on the used market.
The H20 website should be up sometime in the next week or so. I just picked up a pair of the H20 "Signature" Monoblocks last Friday. They have been burning in since. You should be able to click on my virtual system thread which has a link to the Apogee user forum which has much info as well as a few reviews. I was reading all of the buzz on these new amps and drove up to meet Henry in Virginia and listen to his monoblocks on the Scintilla's. After listening to about 1/3 of the "demo" cd's I brought in tow with my preamp, I verbally placed my order with Henry - opting to go with his "signature" upgrade to the monoblocks.

I will reserve judgement until the amps have a few hundred hours on them, however after hearing the "standard" monoblocks on the Scintilla's I began to understand why people were selling their Pass Labs X600's, VTL 450's, eAR, Bel Canto EvoII, etc. amps in favor of these amps.

H20 may not be a known "audiophile" brand at this time... I don't think it will take long for the word to hit the street.
I have been hearing a lot about these H20 does one contact Henry Ho to get more info?
Mezzrow, the website for H20 should be up in the next week or so. I will send you an email with Henry's phone number if you care to give him a call.
Is there any pictures of this amps?
Armandito, if you are asking about the H20, you can click on my system link next to my moniker on this response. They are the monoblocks on the floor next to my speakers. I have one "closeup" that is a bit out of focus if you click on the amp link itself. If you want higher resolution pics, shoot me an email. They are very utilitarian and subtle in design. All sides are 3/8" aluminum, powder coated sides, back and rear in black. The anodized aluminum faceplate can be black or silver. I chose silver faceplates with blue LED. I think Henry has a few LED choices for those that want to match the rest of their gear. "H20" & "M250" are subtlely machined out of the faceplate in the bottom corners of the faceplate.
Here's a good set of pictures here:

Regarding your original questions:

I own the X-600. It is extraordinary. I have the Pass X-1 at the moment (seriously considering the X0.2) and this combo, for the music I listen to (classical, jazz), makes me feel like “I am there.”

You can listen to the “Rite of Spring” at concert-level volume and the amps don't even go near to switching out of class A or getting harsh. A chamber group has all the delicacy and intimate qualities appropriate for the music.

I have no idea why they weigh so much and really don't care, when I get sound of such realism and beauty. This level of performance combined with the fact that the Pass company is just a call away—they answer the phone and are extremely polite— have made and kept me a Pass customer. By the way, I have never needed service on any of their equipment and also am fortunate to own their XONO.

By all means, consider all your options but the X-600 should be one of them. They are the last amp for me.
Actually, the link Rx8man posted are photos of the stereo prototype chassis. Henry is now powder coating the amp except for the faceplate. I am not certain if any internal changes have been made since the photos of that stereo amp.

I know my mono's are different internally, however besides monoblocks, they are also the Signature upgrade...
Vvrinc, I hear you. I live down the hill from the Pass headquarters. I got a personal tour of the facilities. I had been a loyal Pass man for three years. Times are a-changing. I'd bet there are some furious company direction discussions going on now.
I'm with you Vvrinc.Muralman1 what do you mean by "Times are a-changing. I'd bet there are some furious company direction discussions going on now"?

Armando - I think Muralman1 is saying "times are a changing" based on the fact he was once personally singing the praises of the X600's as he owned them... He now owns the H20 mono's. Not to speak for him, but if I remember reading his comparisons correctly the X600's don't hold a candle to the H20 mono's in his system. Muralman1 - please correct any inconsistencies my memory may have misreported.
I do hope “times are a-changing.” Although, at my age, I pray for “a little bit more time” whether changed or unchanged.

It's been my experience that great products stand the test of time. (Kind-a like this “vinyl thing” huh?) Whether Pass Labs takes a new direction for commercial or financial reasons is really no concern to me. The products they have produced–from the Aleph products to the newer X-line—are remarkable. For me, they have the sound I like.

Best regards,
Audiofankj. Your memory serves you well. The difference is really like pulling a wet blanket off my speakers. What seemed like dynamic and clear, becomes lazy and opaque in comparison. Of course, I am speaking from my own experiences with my own systems.
Where's the it up yet?

The site just went up. It's under construction, and leaves a lot to be desired.
Armando, Perhaps it is in fact true that things are achangin'. Even Nelson Pass may be agreeing with all concerned: Pass labs is in the process of redesigning its entire X series, to be now called the X.5. An X600.5 should arrive hopefully in the first part of next year. Do not abandon the idea of X600 yet. But you may want to wait and have a listen to the X600.5 before you make any final decisions. I know I will.
Thanks Guidocorona, I will too.
I don't think so boys. You ought to go to and communicate with the one and only. The physical differences btw the X--- and X---.5: is the introduction of single ended class A bias into the circuit, fast-recovery rectifiers in the power supply, and more efficient output devices in the output stage. Also added was both single ended and balanced inputs. Pass is doing as well as ever. He just has come up with a new biasing scheme to make the X series start sound more like the XA series.
Thank you for the pointer LiGuy. I will visit as suggested. In the meantime, have you had an opportunity to compare the sound of X with X.5 series boxes yourself already?
Guidocorona, please let me know what did you find out?
Armandido, the X350.5 is now already shipping. the Pass engineering team is now concentrating on X600.5. I have spoken to Pass Labs in the last 10 days. The X600.5 should start making music by mid December. It is likely that the new monoblocks will be shown at the Vegas show in January.
By the way, if you want to know more about the new series, I have started a thread to discuss differences between X series and X.5 series.
Armandido, you will find the thread on X series vs X.5 series at the following URL:
See you there!
The Pass Labs site has been updated with full info on the new X.5 amplifier series, including a page on the new X600.5. Shipment of X600.5 should start sometimes during the 1st quarter 2005. The page on X600.5 includes information on details of electrical design changes.
I have just posted a brief update on the development of the upcoming Pass X600.5. Please see: