Monday, May 30, 2005

Conrad-Johnson ACT2 and Premier 350

Source: Streotimes September 2004 (Premier 350), Hifi+ Issue 35 (ACT2) and Issue 34 (Premier 350), Stereophile March 2005 (ACT2), Haute Fidelite December 2004 (18LS pre-amp, Premier 350), The Absolute Sound December/January 2004 (18LS pre-amp, Premier 350)

Conrad Johnson is one of the few audiophile companies with staying power. Over the years it has earned the reputation of making fine vacuum tube equipment, and whilst the company has made forays into the solid-state amplification game, the 350 is of different league.

Some interesting notes concerning zero feedback, dual-mono design of the Premier 350. It uses what CJ call a "hybrid solid-state circuit." This is a very simple circuit topology for a power amp: a FET voltage gain-stage and a bi-polar output stage. According to company's Web site CJ has selected FETs for gain-stage, "because, like tubes, and unlike bi-polar transistors, they produce almost no strident odd-order harmonic distortion." And furthermore: "Bi-polar devices have been specified for the output stages ... because they offer about 1/4th the output impedance of a MOSFET, resulting in much better control of the loudspeaker. This is most noticeable in faster, more solid bass response."

Overall, the design uses very high quality components: "The circuits employ polypropylene and polystyrene capacitors extensively, except in the main power supply storage, where special high-speed electrolytics are used because of the extremely high capacitance required." Those power supply caps are custom film capacitors (Teflon), which excell in their ability to deliver current much faster than electrolytics caps. In terms of music this should result in both faster transients and attack. The transformer is not the typical toroid but an E-I core design with an electrostatic shield. E-I core designs have a narrower passband than toroids thus better noise rejection. The electrostatic shield reduces the noise even further.

As for reviews, the Stereotimes review stated "The performers had dimensionality, the highs were extended, sweet and airy and the bass was fast, deep and nimble. Those words, while helping to describe the sound of the 350 don’t really do justice to it. One meaningful attribute that I can confidently give to the 350 is musical realism."

Hifi+ also compared the 350 with Hovland RADIA, another well-regarded solid stage amplifier: "...sonically they could be brother and sister." RADIA's strengths lean towards intimacy and immediacy, the 350 "is better at being a big amp....". The 350 was found to produce more tuneful, better defined and deeper bass than RADIA. Furthermore, Hifi+ found that the 350 brings to musical performance "a sense of absolute stability, graceful authority", and almost limitless headroom, a combination which "delivers a spectacular soundstage...". Roy Gregory concluded: "listen and you too will be besotted."

French Haute Fidelite in December 2004 echoed. They tested the 350 with the 18LS linestage. Like Hifi+, they noted deep bass ("one of the best in this regard we've experienced"), huge headroom and dynamics, in short, brutal power combined with extreme musicality, transparancy and subtlety. The 350 got the HF Reference Award.

TAS' Anthony H. Cordesman confessed in his review that "The resulting problem from a review point is a lack of drama. If I go on to say that these are the kind of products that are an investment that can provide years of musical pleasure, there is no "hook", nothing to grap the reader's attention." In other words, he echoed the other reviews that nothing in these products jumps on your face, they just sound right. "...auditioning is an experience that I can unreservedly recommend."

Like the 350 the ACT2 linestage has a simple topology: no feedback, one active stage. Design uses high quality components and caps: "Capacitors for the power supplies are exclusively polypropylene, polystyrene, and Teflon - there are no electrolytic capacitors in the audio circuits or their related power supplies" - says CJ's Web site. The volume control uses 24 Vishay resistors (like Mark Levinson has used in its pre-amps for years ;)...). The usage of 6h30 tubes instead of 6922s follows approach taken by BAT and Audio Research with their high-end pre-amps.

Stereophile in March 2005 review noted: "...ACT2 did all those audiophile tricks extremely well...But that kind of obsession with details run counter to the ACT2's real strength, which was presenting music as a whole." Wes Phillips concluded as "ACT2 raises the bar for tube amplifiers...In that, the ARC2 is ... like art itself: I may not know what it is, but I recognise it when I hear it." The measurements showed sufficiantly low output impedance (max. 1150 ohms at 20Hz), extended frequency response (up to 200kHz), and excellent volume-control channel matching (those Vishays).

Hifi+ in issue 35 said "The naturalness of the ARC2's performance rests on its overall coherance. Working back from the whole, it's the evenness of the information across the entire acoustic space that strikes you.", and "The end result is to further divorce the musical performance from the mechanics of its reproduction, to make it more easily understood, more convincing and ultimately more entertaining.". Summing up:" A truly great product puts the music first and on that score the ACT2 score is clarly front-rank".

Viewpoint: Evidently two super products, which together represent a powerfully musical combination that further extends the reputation of this illustrious brand. All these reviews shared the same theme: the reviewers were consistently drawn towards enjoying music instead of venturing into the audiophile semantics.

Some personal thoughts here. First, in the context of audio products, I basically shun A/B comparisons, and overall notion that something is better or the best. This stems from my experince that the key to the high fidelity in sound reproduction is a careful system matching of primary (sources, amplifiers, speakers) and secondary (cables, racks, tweaks) components. Here I make an assumption that the speakers are suitable for the listening room and room acoustics are optimized within a given budget and domestic restrictions. Hence, taking into account of all variables of the primary and secondary components and the listening room, in the context of my audio system "better" is different that better in your system. Hence, the question whether me or you should upgrade our systems based on the glowing reviews is easy to answer.

Second, with CJ's products the reviewers found that it was an exercise in futility to try to describe the sound of the CJ products by running through a checklist of sonic characteristics. They just connected with the music and instead of trying to describe the sound of the component with the idiomatic language of audio reviews they described how they experienced the music itself through the components. This is a fundamental difference and the same phenomenon can be found in all LAMM reviews. But look into any Halcro, Mark Levinson, Krell, Linn etc. reviews - it's description of component's sonic charasteristics, not music experienced through them.

For me the greatest sin of a competently designed hifi component is mediocrity trap: that it does nothing glaringly bad, nothing particularly memorable. Such designs basically have nothing to say, and having nothing to say is not dependent on price. This is the case with most mainstream, high-end manufacturers today. I'm personally fine if a product commits a few minor, acts of omission if it somehow leaves an indelible impression on me - and connects me with the music emotionally. So for all this I salute manufacturers like Conrad-Johnson and LAMM - and manufacturer of my pre-amp, Audio Research.

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