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Equipment Review
December 2006

Conrad-Johnson Premier 350 Stereo Amplifier

by Marc Mickelson


"A special amplifier, one whose sound belies the purely solid-state circuitry behind it."

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Review Summary
Sound "Music poured forth from it without exaggerated speed or space. Its perspective…[was] middle of the road, neither in my face nor distant." "Those 350 watts sounded delicate and natural; they never bullied the music." "C-J's famed golden tonal glow pays special dividends with the Premier 350. It is deftly balanced against the inherent linear sound of the amp's solid-state devices. It never turns cloying, never dominates." "A musical muscle amp."
Features "The Premier 350's circuit is a hybrid of sorts, using J-FETs for the voltage gain stage, likely due to their oft-mentioned tube-like distortion characteristics, and linear bi-polar transistors for the output stage. It employs no feedback, a professed design goal of Conrad-Johnson. As its name suggests, the Premier 350 outputs 350Wpc into 8 ohms, with 600Wpc available into 4 ohms."
Use "Conrad-Johnson makes it very clear in the manual that the Premier 350 inverts phase. They also tell you how to compensate for it by swapping speaker-cable leads, positive for negative for both speakers…. I could definitely hear the effect of inverted phase with the Premier 350 -- a smudgey softness to transients."
Value While the Premier 350's $9500 USD list price hardly makes it cheap, when you consider many top-of-the-line solid-state amps from other companies, this amount is certainly on the low side. And I'm talking about stereo amps here -- don't even consider a pair of prestige monoblocks unless you have mid-sized-sedan money to spend.

Few audio companies have as well-defined an identity as Conrad-Johnson. From the distinctive champagne-gold hue of their faceplates to the tubes that fill so many of the chassis, Conrad-Johnson products have always been immediately recognizable. They are about musical subtlety and sophistication, not bluster and bombast. Visually and sonically they have defined the phrase "understated elegance," and it has been this way for 30 years. Conrad-Johnson celebrated three decades in the audio business this year.

Given all of this, the $9500 USD Premier 350 comes as something of a surprise. It's a high-power solid-state brute of an amplifier in a family of refined medium-power tube amps. On top of this, it has C-J's "Premier" appellation, putting it in the exclusive group of the company's very best products. That it seems like the odd amp out makes its status as Conrad-Johnson's first solid-state Premier amplifier either intriguing or questionable. My suspicion outweighed my curiosity. A Premier solid-state amp? Yeah, right.

My skepticism was grounded in experience. Through the years, I have owned quite a bit of C-J gear, including two Premier products: the Premier 11A stereo amp, and Premier 10 line-stage preamp. Both were sonically wonderful and functionally reliable. I replaced them over time with other amps and preamps, some of which were lateral moves instead of true upgrades. Such is the wayward existence of audiophiles -- at least this audiophile.

Ironically, when the Premier 350 showed up on my doorstep, it would be the first Conrad-Johnson product I'd review. Lucky for me I was limbered up, because the Premier 350 is an awkward, 85-pound mass. Its stout power transformer is on the right side, opposite its bank of heatsinks, with various circuit boards taking up the rest of the amp's 19"W x 8"H x 19"D space. The Premier 350's circuit is a hybrid of sorts, using J-FETs for the voltage gain stage, likely due to their oft-mentioned tube-like distortion characteristics, and bi-polar transistors for the output stage. It employs no feedback, a professed design goal of Conrad-Johnson. As its name suggests, the Premier 350 outputs 350Wpc into 8 ohms, with 600Wpc available into 4 ohms. Even as amplifier power climbs ever upwards, often because of some new switching-amp technology, the Premier 350 remains a very robust amp. It should drive even insensitive MBL and Magnepan speakers without issue.

The Premier 350 doesn't leave much to be said for it in terms of functionality or operation. After the amp is turned on, you can hear a click, presumably from a relay, which is followed a few seconds later by a low-level pop through your speakers. This is the extent of the issues I had with the Premier 350 during its stay in my system. Often I let it run from first light to evening darkness and it only became moderately warm, even after hours of driving a tough load. Inputs are single-ended only, which is Conrad-Johnson's way, and the IEC power-cord receptacle takes a 20-amp connector instead of the more standard 15-amp type. The Premier 350 is protected by eight fuses, five of which are accessible from the rear of the amp.

While the Premier 350's $9500 USD list price hardly makes it cheap, when you consider many top-of-the-line solid-state amps from other companies, this amount is certainly on the low side. And I'm talking about stereo amps here -- don't even consider a pair of prestige monoblocks unless you have mid-sized-sedan money to spend. The Premier 350's price won't get you that car even after a two-year lease.

Review system

The Premier 350 took its place amidst a panoply of fine audio electronics and speakers. I used it with both an Audio Research Reference 3 tubed preamp and the solid-state Aurum Acoustics Integris CDP CD player/preamp; the Premier 350's high voltage gain and sensitivity created some hiss with the Reference 3. Sources were an Audio Research Reference CD7 CD player, an Ayre C-5xe universal player, and Esoteric P-03/D-03 digital separates. Speakers were Wilson Audio Sophia 2s right when the amp arrived and WATT/Puppy 8s when I began writing the review, with Thiel CS7.2s in between. Other amps for comparison were Lamm ML2.1 SET and M1.2 Reference hybrid monoblocks, and an Audio Research Reference 110 stereo amp.

Interconnects and speaker cables were either Crystal Cable Ultra or Shunyata Research Antares Helix and Orion Helix. Power cords were all from Shunyata Research and included Anaconda Helix and Python Helix in both Alpha and Vx varieties. Because of the Premier 350's 20A connector, I also used the stock cord that came with the amp as well as Audio Research's stock 20A cord, which sounds darned good to my ears. A Shunyata Hydra Model-8 conditioned power until a new Hydra V-Ray showed up. I'll be writing about the latter sometime in early 2007.

Conrad-Johnson makes it very clear in the manual that the Premier 350 inverts phase. They also tell you how to compensate for it by swapping speaker-cable leads, positive for negative for both speakers. (I used the phase-inversion feature of both the Audio Research Reference 3 and Aurum Acoustics Integris CDP instead.) I could definitely hear the effect of inverted phase with the Premier 350 -- a smudgey softness to transients -- but this was only the beginning of the sonic discoveries to come.

Premier solid state

So often with burly solid-state amps like the Premier 350, the first thing you hear from them is all that power. This manifests itself as a forceful authority, the sense that the amp's high power is its most salient sonic feature. Such power can make for thrilling sound, especially in terms of the dynamic possibilities, but it can also lead to music that lacks the unforced ebb and flow of the real thing. Such amps seem to subjugate the music to their will instead of allowing it to emanate from the speakers in a natural way. They can make great hi-fi, but they don't create the illusion of singing, playing musicians.

I honestly expected nothing different from the Premier 350, even given all of my past experience with Conrad-Johnson gear. Audio prejudices die slowly -- when they die at all. Yet, right out of the box, the Premier 350 had ease and subtlety in abundance. Music poured forth from it without exaggerated speed or space. Its perspective -- where it placed the musicians in relation to the listening seat -- was what I had come to expect from my reference Lamm tube and hybrid amps: middle of the road, neither in my face nor distant. But, most of all, those 350 watts sounded delicate and natural; they never bullied the music, never cranked up its forcefulness or leading-edge definition. Instead, I heard naturally rendered sound backed up with abundant power -- music touched by a silk glove instead of hammered with an iron fist.

I wrote about La La (www.lala.com) in an early SoundStage! Update, and I am just as enthusiastic about the site now as I was then. In case you don't know, La La is a CD trading service. You create a Have List of CDs you are willing to send to others and a Want List of titles that you hope to receive. You pay $1.75 for each disc, which includes postage, and you get to keep whatever you get -- unless you decide to trade it to someone else. Even though I am a musical omnivore, La La has expanded my musical palette, and one of the most interesting CDs I've received is a collection of numbers made famous by Bill Evans played by classically trained pianist Jean-Yves Thibaudet. Conversations with Bill Evans [London 455 512-2] is a spacious though dry-sounding CD that melds jazz with the sound of a classical recital. That the Premier 350 captures all of its detail is not noteworthy; most amps will. However, it is significant that it presents the music with an organic ease while never glossing over its spaciousness or touch of arid edginess. Again, the perspective is just right -- the recording's own sense of space gives cues to this -- and so is the piano, which is rife with the sound of both hammer and string. "I think I can hear the distance between the microphones and the piano" say my notes, such is the unforced resolving power of the Premier 350.

C-J's famed golden tonal glow pays special dividends with the Premier 350. It is deftly balanced against the inherent linear sound of the amp's solid-state devices. It never turns cloying, never dominates. No matter the recording I played, even the most voluptuous-sounding Telarcs in my collection, instrumental timbres remained honest and convincing, drawing attention only because of their wholly natural sound. I never thought I'd write that about a solid-state amp, but then none that I've heard has performed quite like the Premier 350. The high-frequency sophistication of good SACDs was especially well served by this amp. It conveyed overtones that could easily be lost to the recording's own noise, yet it never thrust more prominent elements at me, like the blat of brass or some aggressively bowed strings. This is a theme of the Premier 350 -- detail without aggression, ease without obscurity. It's surprising how many amps can't handle the things that the Premier 350 has mastered.

And this may lead to the best way to sum up the Premier 350: It doesn't have the sonic tendencies of so many solid-state amps, some of which are bona fide bad habits. Does this mean it sounds like a tube amp? In some general ways, yes, but I would still not mistake its transistors for tubes, and it doesn't attempt to somehow bridge the gap between high-end audio's two kingdoms. Instead, the design minds at Conrad-Johnson have engineered a new breed of solid-state amp, one that balances what they like about tubes so deftly with the power of solid state that it's academic to discuss if it's more one than the other. Simply put, the Premier 350 is a musical muscle amp.

Like so many things about the Premier 350, the bass is not conspicuous, although its power is easily heard when the music demands it. While the low end lacks obvious bloom, often the byproduct of a swollen midbass, it goes very deep. The Premier 350 can also bring a sense of dynamic life to speakers that need power to achieve this. I listened for blissful days to the Premier 350 driving Thiel CS7.2s, thinking so many times that I could spend six figures on a speaker-amplifier combination and not have sound half as good. The Premier 350 seemed like the perfect amp for the big Thiels; hopefully Conrad-Johnson and Thiel will be curious enough about what the soon-to-be-available CS3.7 and Premier 350 would sound like together to demonstrate this combo an upcoming audio show.

So much audio reviewing boils down to preference -- absolutes are hard to come by, especially in the realm of the highest performance that high-end audio has to offer. Certainly what I have praised about the Premier 350 addresses my deeply felt sonic preferences, but it also makes the notion of preference seem inconsequential, in such a complete and human way does it reproduce music -- its detail, timbre, dynamics, and perspective. The Premier 350 pushes my buttons and rattles my cage, but after even a short amount of listening, I hardly know it -- or care. It appeals on a nearly subconscious level, where personal definitions of ideal musical reproduction exist. It's like a narcotic that dulls petty audiophile concerns. It's.... It's....

Time to stop typing and do some listening!

Dare to compare

Of all the amps I've reviewed recently, the Ayre V-1xe ($9000) would be the best to pit against the Premier 350. Both are very powerful solid-state stereo amps from well-established companies, and both cost a touch under $10,000. I wrote a review follow-up on V-1xe earlier this year, but the amp was here for such a short time, and it tagged along with Ayre's K-1xe preamp, that I simply can't make a call as to how it would fare next to the Premier 350. I will say that if you're considering one of these amps, you should make the effort to hear the other.

Just as significant, however, is a comparison of the Premier 350 to the Lamm M1.2 Reference monoblocks ($21,690 per pair). The M1.2s, and the M1.1s before them, have been one of my reference amps for years, and they appeal to me on a deep level as well -- I've owned even more Lamm equipment than Conrad-Johnson. Like the Premier 350, the M1.2s have an unpretentious way of reproducing music. They get the viewpoint right, never sounding forward or recessed in any region. Music flows at its own realistic pace; it always resembles reality and is never a clinical-sounding facsimile. I wouldn't be rich if I had a dollar for every time I described the sound of a Lamm amp as "natural" or "organic," but I'd be able to buy a good dinner with drinks and dessert.

Thus, as you might be able to guess, comparing the sound of the Premier 350 and M1.2 Reference is really an exercise in identifying small differences, because in broad terms these amps sound very much alike. The Lamm amps are hybrids, using a single 6922 tube in each, and you hear this in the sound, which is more full and bloomy in the bass than that of the Premier 350, and more resolute and substantial in the midrange. There is also a greater physicality to images, which are more rounded but slightly softer in terms of their outlines. In the treble, the solid-state Premier 350 has the character of the finest silk thread. High notes and their overtones are drawn out to nothingness, receding into a blacker background than they do with the M1.2s. This was especially discernible with piano, where the Premier 350's lack of tubes made for crisper notes with better separation from each other. Both amps cast big soundstages; the Premier 350's had slightly greater illumination, whereas the M1.2's was more dense and atmospheric, perhaps due to the chunkier images.

Of course, the two biggest differences between the Premier 350 and M1.2 Reference are in terms of power output and price, and in both cases the Conrad-Johnson amp comes out far ahead. While I don’t think that M1.2 Reference owners should rush to trade in their amps on Premier 350s, audiophiles who have coveted the Lamm amps but didn't have the budget for them or needed more power now have a very attractive alternative.

Concluding thoughts

This year has been a remarkable one in terms of review products. From January to now, I have had a steady diet of great speakers, electronics and cables, an unusually high percentage of them earning the Reviewers' Choice tag for state-of-the-art performance. In theory, such high water should raise all boats, making it even harder for succeeding products to achieve the same levels of praise; in practice, astonishing audio gear just kept coming my way, much of it equaling, or bettering, the performance of whatever had just left. While consistent excellence can make listening more enjoyable, it makes writing more difficult, especially as the performance of products entangles as it converges on the same goal. There is more sonic variation at lower price points; the really good stuff -- what I spent much of 2006 reviewing -- starts to sound more alike than different.

This review will obviously be my last of 2006, and in some ways its subject has been the most satisfying I've encountered all year. The Premier 350 is a special amplifier, one whose sound belies the purely solid-state circuitry behind it. Its high power never bullies the music, and its slight honeyed tonality never prettifies to the point of saccharine sweetness. All of the solid-state earmarks are there, including deep, stalwart bass and enough power to deafen, but so are a delightful musical rightness and an easygoing way with detail. The Premier 350 will challenge your perception of solid-state amplifiers, no matter what it is.

A Premier solid-state amp? You bet!

...Marc Mickelson
marc@soundstage.com

Conrad-Johnson Premier 350 Stereo Amplifier
Price:
$9500 USD.
Warranty:
Three years parts and labor.

Conrad-Johnson Design, Inc.
2733 Merrilee Drive
Fairfax, VA 22031
Phone: (703) 698-8581
Fax: (703) 560-5360

E-mail: service@conradjohnson.com
Website: www.conradjohnson.com

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