Conrad Johnson Premier 12 tube monos

Has anyone heard these and/or compared to any other 6550-based amps of similar power (140 watts) range?
I had these in house,while waiting for my Air Tight ATM-3s.Very musical and dynamic,but not the last word in down-to-the-noise-floor resolution.That said,they were enjoyable and very dependable,with a musical harmonic structure.
Tpsonic- thanks for the feedback- I actually had the ATM-3 monoblocks in my place as well for a quick session (I have also owned the ATM-4). Very 'full' sounding, but perhaps not as 'fast' as other amps I have tried- truly, I don't think I gave them enough of a chance... How do you like them vs any other tube amps you have tried?

I owned a pair of Premier 12s for several years and had a chance to compare them to the ARC VT100 mk2 and CJ Premier 140. Ran them with the GE 6550As they were originally voiced with along with an RCA double-mica black plate 5751 and military issue Sylvania 6FQ7s. The 12s are excellent representatives of the 'old world' pre-21st Century CJ house sound.

As you note, they are 'full', which I take to mean harmonically rich and a touch warm - definitely to the yin side of things. Nice bass extension though not quite as crisp on low end transients as say the VT100, yet to my ears, harmonically much more pleasing. Very good sound stage width and depth with reasonable interior dimensionality on woodwinds, choristers, etc. Not quite as resolving and not quite the punch of the Premier 140 nonetheless quite satisfying over all.

Modern day they will do fine with the Svetlana 6550C and RCA clear top 6CG7/6FQ7s. Stock they do not have an IEC plug, but they most certainly benefit from a simple rewire to a decent mid-range power cord such as a Shunyata Diamondback which will really tighten up the bass and yield better overall resolution.

AS Tim has said, the 12's are wonderful sounding tube amps.
Just make sure your speakers are not low impedance into the bass frequencies otherwise they will struggle like most tube amps.
Other than that, beautiful amps
The ATMs were very much a midrangy affair,though they did mate with the Yankee FPR 72s very synergistically.The Siemens EL-34s were a must in that amp,not the AEGs.Better drive in UL,but lost that beautiful midrange lushiness.Resale is terrible.Alot of picking a tube amp has to do with the speaker being driven-planar,dynamic or electrostatic.What speakers will you be mating up to the "future tubes"?
Guys- great responses- thanks. Speakers are 97 db 14-ohm Coincident 'Victory' model with Ribbon tweeter. On paper, you may be thinking even SET, but them seem to like more power, and my room is HUGE open concept. Preamp is modded Sonic Frontiers Line 3. I used to have the ARC VT-100 MKIII- that worked well with my Pre.

Should also mention this system is used for 2-ch HT as well, so I do appreciated an amp with low noise floor and good bass capabilities, which is why I decided to try the '6Moons SS favorite' Audiosector Pateks- running them in mono (balanced- sonically great on many fronts- however I do miss the 'X factor' of added tube dimensionality- particularily in the extra decay of the notes a good tube amp can bring).

I believe the Premier 12's are single-ended only, therefore not taking advantage of the fully balanced architecture of the preamp, however that is not 'make it or break it'- I would consider single-ended amps like the Premier 12's if they really ARE that good. Other than the ARC VT-100 MKIII, not sure what other fully balanced tube amps there are at under $5k used that are better than the ARC- I hear VAC makes great stuff, but $$$...

Other than the ARC VT-100 MKIII, not sure what other fully balanced tube amps there are at under $5k used...

You owe it to yourself to try fully balanced Atma-Sphere M-60s. Used they easily come in under $5k (new around $6k iirc). Do not for a moment doubt their 60 watts with those speakers. With your Victory's, I'm tempted to say that you either will be blown away or you are tone deaf, but that would be impolitic of me, so I won't. ;->

I had the 12s for years, liked them a lot, was only seduced away by some SET monoblocks (845 output tubes). The SETSs supposedly produce only 12 wpc but sound more authoritative (in an 18 x 40' room) than the CJs did. Good luck, Dave
The Atma-Sphere M-60 MkIII would be an outstanding match with your Coincident Victories, as Jtimothya suggests. Authority in the bass with excellent resolution and quickness, plus a midrange timbral accuracy that few other tube amps match. Don't let the 60w rating fool you - with a 14ohm load, this OTL will exercise more control and deliver more power into the Coincidents than other nominally higher powered amps, and you can't beat the Atma-Sphere's transparency, resolution and harmonic truthfulness.
Get yourself a Music Reference RM200, unless you want the overly warm sound of the CJ 12's... Plus the Music Reference is fully balanced design. The Music Reference is more transparent than the ARC VT100 MkIII and way cheaper to retube, plus you can try Kt88's or Kt90's to take it even a step further depending on what you like and system synergy.
re: Atma-sphere- concerned about heat and hot tubes exposed (have 2-yr old running around in that same room). Dopogue- in fact, have tried 845's before in the system, and liked them very much. A local guy has a set of J.C Verdier 845 monoblocks that I hear are very good...
Cyto- Music Reference?? Don't really know them, but will look into it- thanks again everyone for the great responses!
You might want to audition the PrimaLuna KT-88 monos.I would definitely upgrade the input and driver tubes,along with an after-market PC.Check their audition policy,don't know if there is a re-stock charge.For $2700,the other upgrades might leave some leftover cash for music.