VAC vs Conrad Johnson Amps?


I have had my Conrad Johnson Premier 12 140w/side tube monoblocks for many years and loved them.  Essentially they sound to me like Michael Fremer had described them in his long-ago review:  the CJ tube magic, with zest, power and control.  They've been able to drive pretty much every pair of speakers I've had, large or small.

At the same time I've always had some lust for the VAC amplifiers.  It started long ago when I heard VAC amps make Thiels sound like I'd never heard them before - liquid, astonishingly transparent and musical.  I managed to get much of this with my CJ amps paired with my Thiel 3.7s (and other speakers), but given that transcendent moment with VAC, and knowing how many of the highest end speaker manufacturers choose to use VAC and display their speakers with VAC amps, I'm left wondering "What If..."

I see people happy with amps like the phi 200 but I sometimes see the Phi 300.1 become available second hand (the only way I could afford that one).  It's 150W per side vs my CJ 140W, and I've read the VAC has good reputation for bass performance (I like good bass control) and driving many big speakers.  I wonder if any of the possible quality of the VAC would be off-set by the purportedly better separation you get with monoblocks - e.g. my CJs.

As I mentioned, I'm currently using Thiel 3.7s, with some 2.7s arriving soon, but I also own MBL 121s and like to keep my options open.  I'm also interested in the Joseph Audio Perspective speakers so would want an amp that has good grip on ported speakers as well.  I wonder what I may gain, and/or what I might lose, going for a VAC phi 200 or especially the 300.1, vs my CJ Premier 12s.

Anyone who has helpful experience to contribute, please do so!  Thanks!


prof

I don't know if tube amps are your best choice with Thiels, but since you've used them in that capacity, what can I say.

It is apparent that you really want a VAC amp, like the way they sound, look and work with a variety of speakers etc. .   So go ahead and get one (or two) .  If it doesn't work out, then sell it or it /them.

Spec wises you are comparing Apples to Oranges!

Cj spec not close to Vac!  If you want power without the sweetness then CJ is for you.   Remember cj amp runs on Class a&b not pure class A like the Vac.   Vac will give you an even tone, sweetness but lack of power.  Take your pick?   

If i were you stick with vac but get a bigger amp, which will give you more power but in the mean time have the sweetness to it.   CJ amp doesn't come close to the Vac design!!! 
mechans,

I'm investigating the idea of a VAC amp, but not sure I want to make that investment yet, which is why I'm seeking the experience of others.  The buy-and-try price is very hefty for us Canadians!

I do prefer Thiels on tubes (having heard them on both SS and tubes).

zipost,

I'm confused by your post.  What do you mean the specs are not close?
The wattage is almost the same.  And it's very strange to read someone saying CJ's don't have "sweetness" when that is one of their main features.  As for power...I kept reading the VAC is very powerful.
And I con't have a VAC so can't "stick with it."

Sorry...can't make heads or tales of what you wrote, could you be a little more clear?  Thank you.


Put both amp specs side by side comparison: The CJ Premier series is an old series ( old technology), that amp runs on Class A & B design, not pure class A.   The phi series 200 or 300 is a class A amp design, not only it’s a better amp made but will sound better running on class A.   Not a real comparison!  





Prof;

ahhhhh.........
You've opened another can of worms...

A audio buddy of mine, has VAC stuff
He has Cary stuff & ARC, too
And, Pv-14 CJ that he had/ has problems with

He likes the sweeter highs & details with good tone
He has a range of speakers ; great speakers

He has ended up with a Cary Preamp (. -05) & ARC VT-100 power amp

& it sounds good

LOL

I think he likes what you're preferences Are, too;  & Toob rolls

It appears you need to try lots of combinations, again

Jeff
It is my understanding that the VAC Phi series of amplifiers are class AB and not pure class A circuits.  They certainly may have a high class A bias.  If I'm mistaken then my apology. 
Charles 
In the past ( and maybe present) VAC used the Thiel to voice their equipment.
Charles1dad 6-28-2017

It is my understanding that the VAC Phi series of amplifiers are class AB and not pure class A circuits.

I’m pretty certain that this comment by Charles is correct. One indication of that can be inferred from the ratings of the mains fuses that are used, which can be seen in rear panel photos that are available on the web. For 120 volt operation the Phi 200 (for which the two channels are rated to provide a combined total of 200 watts) uses a 5 amp fuse, and the Phi 300.1 (for which the two channels are rated to provide a combined total of 300 watts) uses an 8 amp fuse. Assuming something like a 2:1 margin between the current rating of the fuse and the actual amount of current it would be conducting, that would mean a maximum AC consumption of about (120 x 5/2) = 300 watts for the Phi 200, and (120 x 8/2) = 480 watts for the Phi 300.1. Those consumptions are **much** too low to be consistent with pure class A operation for the specified output power ratings. A pure class A 200 watt tube amplifier would probably consume somewhere between about 800 and 1000 watts continuously, while a pure class A 300 watt tube amplifier would probably consume somewhere between about 1200 and 1500 watts continuously. Those kinds of AC power consumptions would blow the specified fuses almost immediately.

Regards,

--Al

God love 'ya, Al, I know we all do!
He's an encyclopaedia! And yes, we all love him.

Hi Al,

That sounds right to me in terms of the figures you stated. My 8 watt 300b mono blocks SET (class A by default) consume 180 watts per owner manual spec.. The fuses are 3 amps. 120 x 3/2 = 180.

Charles

Back to the issue of sound, I've heard both for many years. As much as I love Bill and Lew, the VAC gear is on another level of music reproduction. The prices are iirc, likewise.
VAC will drive the 3.7, BUT, I would call Kevin Hayes personally and talk to him and get his best advice. He will be forthcoming, and is a prince to deal with.... great man, great products.
Larry
Thank you Irsky!

Anyone have any idea of the sonic differences between the Phi 300.1
and the Phi 200?

On one hand my rack space is low and I like the idea of downsizing from 2 monoblock amps to a single amp - though of course I don't want to lose quality, and I presume VAC will be a step up.

On the other hand, the 200 is cheaper and can add a second one later.

Thoughts?
Vac Renaissance is all Class A. I Heard a 30/70 sig, and 70 mk. 3.  I enjoyed the CJ Premier 8a very much, and the teflon upgrade may take them to another level. I also owned a Vac Phi 300.1, and a Standard 220 Signature. If I were to return to a low-mid efficiency speaker, I would look to the Vac Renaissance. Cheers -Don
Prof 

There is a gentleman selling both a VAC 200 and Premier 12 monos on Agon. You may want to PM him directly for his impressions on both. In any case good luck with your quest.
The Renaissance series of power amplifiers are a different breed from Phi offerings. I’m very familiar with the Phi 300.1 mono blocks. . In the realm of Pentode tubes in a push pull class AB circuit they are definitely uppermost tier. Very tough to beat in this genre.

The VAC Renaissance was a very different design approach. 300b (DHT rather than pentoode/tetrode output tube) push pull with superb quality power supply and transformers. With a properly matched speaker you’re talking premium grade sound quality and a DHTinspired  beautiful natural midrange. Two different pathways. 
Charles
fjn04

Why would you go to a Vac Renaissance, after having owned the Phi 300.1?


tubegroover,

Thanks for the heads up!
Just buy it, you have to listen at home.

VAC Kevin said they design these amps with a dozen sets of speakers and anything they do that makes 11 sound better and 1 worse is rejected.   Class A or AB no matter as the input and driver are Class A and the UL or Triode modes give you plenty of options.
Kevin says "rich AB1"
I recall the Renaissance amps to have a very engaging sound, that to my ears, was more enjoyable. I am a big fan of the 300B tube, which is the tube my current SET amps use. Again, given the right speaker (89-93db), I would not discount the Renaissance amps. 
Prof,

Speaker mating is important especially with many tube amps.  I had a VAC Phi 300.1A and it drove my Focal Utopias very well with ample bass control.  When I upgraded my speakers to Rockport Altairs, I lost a good deal of bass reproduction. It seemed like the frequencies from approx 100 - 160Hz were lean and as a result overall speaker coherence suffered. I later confirmed this when I switched to a solid state amp with lots of current as the bass coherence with the higher frequencies is terrific.  
I don't know much about your Thiel's and the other speakers you're considering, so perhaps they're less demanding and the VAC will drive them very well.
As others have said, Kevin Hayes is an exceptional gentleman and should be able to provide some professional guidance.
Just want to say:

Thanks for all the input, fellas.

It turns out I'll have enough on my plate (financially) in sorting out my new speakers so I'll have to put off any amp upgrade for now.  (I was tempted by the VAC 300.1 for sale on audiogon).

I'll save this info for when I'm ready to buy VAC (if that happens).


I've owned one CJ amp (Premier 140), but it sounded like solid state, so I've kept my distance from CJ.

I currently own VAC Renaissance 30/70 MkIII Sigs, which replaced a Phi 200 (missed the finesse of Renaissance amps), which replaced a 70/70 Signature (very heavy), which replaced a 30/30 MKIII (wanted more power).  Sounds crazy... I know.  The Renaissance amps are superior to the Phi 200 with regards to vocals, strings and acoustic.  The Phi 200 has the best bass of any amp (solid state included) I've owned and excels with classical and blues.   

I've enjoyed my time with both the Renaissance amps and the Phi 200... they just excel in different areas.  The Renaissance amps offer more nuance and finesse, allowing you to hear deeper into the music.  The Phi 200 has more drive and power with explosive dynamics.
pdreher,

Wow, that's the first time  I've ever heard someone refer to a CJ tube amp as sounding like solid state (especially an older CJ amp).

Thanks for the insight into the sonics of the VAC amps.

Some day...
It's quite likely that the CJ Premier 140 was a departure from the typical CJ house sound, so take my experience with the Premier 140 as an outlier.    
CJ Premier 140 was most definitely NOT anything close to a Premier 12. As a former Premier 12 owner I can tell you [when equipped with SED Winged C 6550's ] it is one of the finest amplifiers ever made. Natural, realistic, and very capable of effortlessly bringing the best out of my 3.8 ohm Apogee Duetta Signatures in a moderate sized room. The Premier 140 was likely more extended in the bass and probably more technically adept in certain areas but imho never managed to express the fluid continuousness and pure magic of the Premier 12's. 
lissnr,

I certainly agree about the attributes of the CJ Premier 12s.
"Balance" is the key description, and the one that Michael Fremer used as well.  When I tried various contender amps (at the time) there always seemed to be a sort sculpting (deliberate or not) of the sound - full but rolled off, extended but thinner, emphasis here, detraction there.  But with the CJs everything just seemed in perfect balance - they are almost like coherence-machines in terms of helping achieve that in any speakers I've used.  They somehow do the tube magic thing, while also disappearing because nothing wrong or obvious sticks out either. No fat bottom bass, rolled off highs or whatever.

I just figured that VAC may provide a step up from the CJs, perhaps in terms of further transparency or other goodies.
VAC, inseparable from Kevin Hayes and that's a great thing.  Kevin's passion and expertise brings value beyond what you hear from your speakers.  For instance, Kevin doesn't voice his equipment to anyone one speaker model, brand or type.  He's been known to half the distribution of an app because it didn't sound quite right with one speaker out of many.  That's dedication and customer service before there's even one customer.

I own the Standard 160 Musicblocs and my brother owns the Phi 300.1. I have Nola Contenders speakers, which the VAC 160s have more than enough power, but have great dynamics across the full range. My brother runs 86db sealed speakers that the Phi 300.1 handles better than his previous Lamm mono amps.

Beautiful amps made with passion, to last for decades with excellent sound quality.