Conrad Johnson 350 vs Pass Labs X amp

I have a CJ 17LS preamp, CJ Premier 11A power amp and Quad 989 speakers. I'm planning on upgrading the power amp and was thinking of the CJ 350. I don't need 350 wpc but I'm attracted to it because people are saying its the best amp CJ have yet made - even better than the 140. However I've also been reading very good things about Pass Labs amps and was wondering about the X150.5. Has anybody compared the 350 and the X150.5?
PS. You may say I should be comparing the X350.5 with the CJ but as I understand it the only difference in the X amps is the power output, and as I said I don't need 350 wpc.
"The only difference in the X amps is the power output"--there's a little more to it. The ones with more power also have more Class A power--which is what you want for best sound, having less distortion and a richer tonal palette.

From what I read here, the X350.5 is considered by Pass to be their best-sounding implementation of the '.5' upgrade.
I think both Pass and CJ are great and do'nt think you can go wrong with either. I use a CJ Premier 17 with a Pass Aleph 3, a very different beast than the X150, but it sounds great. All the reviews of the CJ 350 in the UK have been very complimentary. I heard it with the ACT and Avalon Eidolons at the recent UK Hi-Fi show and to me it was the best sound in the show by far
I take your point on the level of available Class A, thanks.
OK, it seems that nobody out there has compared these two amps, so has anybody got anything to say about about either of them on their own merits?
The most exquisite sound available (to my ears) in 1986 was the c-j Premier 3 preAmp with the 200 watt Premier 5 monoblocks driving the SoundLab A-1s. I lived in San Diego at the time, and was unusually fortunate that my local dealer helped me to audition and actually A-B everything of quality then being manufactured.

I'm now in Amherst, Massachusetts, and am in the process of building a new system for my new house. The idea of demo-ing everything is clearly out of the question, particularly in light of the sheer numbers of hi-end tube equipment now available. Hence, I am relying quite a bit on the A'gon members' thoughts.

My Premier 3 is currently at the conrad-johnson facility, being cleaned up and refurbished in preparation for sale (let me know if you want a Pr. 3). I have replaced it with the Premier 17LS (bought used on A'gon). This decision was based on reviews, forum comments, and my own respect for c-j's sound and excellent service. I might do some comparisons for kicks, but if I do, it will be limited to the Supratek models, the First Sound, and maybe the H-Cat.

In regard to amplification, my first instinct was to stay with tubes, either the c-j 140 or SET monoblocks by Cary or Audio Note. However, the low output of most triode amps made me re-think things, and I came to the c-j 350. My thinking at this point is that, if such strides have really been made in solid-state sound, then perhaps my tube digital source (Audio Note) and tube PreAmp (the c-j 17LS) might just be complemented, or at least not be adversly impacted, by the ss 350. This choice is also important in light of the 350's ability to drive most speakers, as my SoundLabs died and I took them to the city dump...I'm leaning toward replacing them with Quad 989s or ?.

So, my personal choice at this moment is the conrad johnson 350. I anticipate exceptional sound through Quads. I'm therefor looking for one now, and if it sounds as good as it should, I'll keep it. I am so very much a cj fan, based upon 20 years of experience with them, that any minor improvement in sound from a different unit, if possible) would not be enough to sway me.

But of course, the only way to know for sure is to listen. I realize that all this has been absolutely no use to you, but when I get the 350 and do some listening, I will report to you my impressions.
Do you have long interconnects?.
I tried a pass 350 with my prem 16 earlier in the year with poor results. Slow rather ponderous sound. Could have been that my prem8a's were a lot better, but I think the cj pre amp may have been having trouble driving my 6 metre i/c's.
cj don't recommend long i/c's.
The CJ has a very layered and rich sound with a very wide and deep soundstage and focused images. The Pass has a livelier sound with better extension at the frequency extremes and larger images. So its like trying to decide between blondes and brunetes: both are good. So the ultimate solution is to get both amps. Who cares if its a little expensive? You only live once.
Ethnos - thanks for your post, I will be very interested to hear what you think of the 350 in that set up as it would be the same as mine if I bought the 350.

I got a chance to audition a 350 a few days ago and compared it to a MV60 which is meant to be similar to my Prem 11A. There is no doubt that its a much more dynamic amp with better definition and speed, particularly in the lower registers. It is however a shed load of money as we say here in the UK and a X150.5 would be a lot cheaper. As a bonus it also looks wonderful. Now if I could only afford a pair of XA100s my decision would be easy . . .
I have a 350 and it is very good, the best I have heard to my ears. It drives difficult loads with ease. My Gamut L5 will shut down my Meridan 605s after making the heat sinks very hot. These amps drove my Apogee Dutettas easly. The heat sinks on the 350 get barely warm. I might be loath to use them on Quads because of the power; if you do use restraint.
Martin Colloms found them very good also
I had the pleasure of listening to this outstanding CJ power amp mated w/ the Act2 Series2 CJ pre-amp.  Today, this is still my reference until I can hear an ART3 CJ pre-amp.  My listening sessions took place in 2007/08.

Would love to read more about those who have demo'ed this amp.
Keep me posted & Happy Listening!
The Pass Labs amps are said to be ideally suited for pres with low output impedances and balanced outputs. The c-j's are obviously most likely to be very compatible. c-j has recently introduced some new ss amps. While some have noted that the newer ss amps don't seem to have as sturdy transformers as their earlier offerings, they do appear to offer some upgraded teflon caps and other parts. Perhaps a lower powered c-j with such upgrades might be a consideration. Not knowing your speakers, etc., makes making recommendations problematic. The Pass Labs might be slightly better at handling low impedance loads. FWIW, I fan of both c-j ss and Pass Labs.
I've owned the Pass Labs X150.5 amp,  at the time using an Audio Research LS2 tubed pre - unbalanced.  So I had a kinda/sorta "hybrid" set up,  solid state with the Pass,  tube with the ARC.  I obtained the Pass shortly after buying a First Watt M3 amplifier through the same dealer.  I would mention the dealer but I'm not certain if the site would permit that.  I sent back the M3 and purchased the Pass.  

These were heard through a pair of Thiel CS 3.5's which,  with the supplied electronic crossover,  had a frequency range of 20hz to 20khz.  Then,  as now,  I used Anti-cables throughout.

Unfortunately I was bitten by the unobtanium virus and I foolishly traded the amp away to fund a McIntosh amp.  A used/refurbished Pass Labs X150.5 currently costs DOUBLE what I paid for it in the same condition.

I am currently scouring the web for the X150.5.  Should never sold it.

Thanks! for sharing- oblgny.
We Thiel-lovers, have to stick together!

Keep me posted & Happy Listening!