Audio Research • Reference Anniversary Preamplifier

by Marc Mickelson | April 23, 2011


April may be "the cruelest month," as T.S. Eliot wrote in the opening to "The Waste Land," but he certainly didn't have the Audio Research Reference Anniversary preamp in mind when he penned one of his most famous lines in 1922. It seems like Audio Research began making audio gear in 1922, but it's only been since 1970. William Z. Johnson launched his company -- at the time, the only one in the US making vacuum-tube audio electronics -- with a single amp and preamp, but more than 50 different amps and 30 preamps have followed. Preamps have become Audio Research's signature product, beginning with the SP-1 in 1972, which cost $750 and commands as much on the used market today. Audio Research's first two-chassis preamp was the $3500 SP-10, which was introduced in 1982, and this was followed by perhaps the grand dame of the company's vintage preamps, the $4900 SP-11, in 1985. Audio Research introduced its first Reference-series preamp, the Reference 1, in early 1996, beginning a run of models that leads up to the current Reference 5.

What the vacuum tube does any of this have to do with April? It was a year ago this month that Audio Research decided to celebrate its 40th anniversary. While some companies would throw a lavish party, Minnesota modesty dictated that Audio Research would create a commemorative product instead. It had to be a preamp, given the company's legacy, so the Reference Anniversary was born. It is the first two-chassis Audio Research preamp in 20 years, and it takes advantage of the collective knowledge the company gained during its long tenure building tubed audio electronics.

The Reference Anniversary's two chassis were necessary because of the ambition of its design. It features truly separate signal paths and power supplies for each channel and twice the power-supply energy storage of any previous Audio Research preamp -- 8000 microfarads in total. For comparison, Audio Research's VS115, a 115Wpc stereo amplifier, has 3760µF. The most visible internal parts, even more so than the tubes, are the four huge Teflon coupling caps created specially for the Reference Anniversary. Each weighs over two pounds and is the size of a pop can cut in half. Eight 6H30s, the latest breed of dual-triode tubes, reside in the main chassis, providing the gain. These were chosen for their high transconductance and low noise, which translate to better performance than the more common 12AU7 or 6922. Two more 6H30s are in the power supply, each driving a single 6550C pentode, a common amplifier output tube. Like the tubes in the main chassis, those in the power supply are dedicated to separate channels, signaling that the Reference Anniversary is dual mono from the 20A power-cord inlet to the volume control. This is a noteworthy feat, given that it's all tube and fully balanced as well.

Functionally, the Reference Anniversary is identical to the Reference 5 (and Reference 3 before it). The vacuum-fluorescent display is the same, and the remote control for either unit will operate both. Some people have carped that the Reference Anniversary deserves a chunky, hewn-from-a-block-of-titanium remote, but I disagree. Audio Research's elegantly simple remotes blend with the visual simplicity of the products, and they aren't so bulky as to break if you drop them -- or so heavy as to damage whatever they fall on. And if you lose the remote, you won't have to pay an outrageous amount for a replacement. Probably the most forward-thinking of the Reference Anniversary's functions is the tube-life counter. No more will you have to guess at how much time the tubes have been in operation -- the preamp will tell you at the push of a button.

Aesthetically, the Reference Anniversary represents a further refinement of the well-established Audio Research style. You can have black or silver faceplates and handles, although in either case the row of buttons on the front remains silver. The chassis are big, so you'll need some serious room on your rack for them. They link with a pair of umbilicals that you must be careful neither to connect nor disconnect when the preamp is plugged in. Thinking ahead, Audio Research warns you of this with a can't-miss-it sticker on the back.

Prior to receiving a new Audio Research product for review, I normally get a primer from Warren Gehl, the company's in-house listener, regarding break-in. Before Warren and I talked, I had heard rumors that break-in for the Reference Anniversary was an ordeal -- at the 500-hour mark, I'd just begin turning the sonic corner. The cause is those large Teflon caps, which require a great deal of use before they're conditioned sufficiently to sound the way they ultimately will. I can't confirm or deny the 500-hour rule, however, because the unit I received had clocked over 1000 hours of use. Fortunately for Reference Anniversary owners, the 6H30 tubes are rated for 4000 hours and the 6550Cs for 2000, and retubing doesn't require a new break-in cycle.

More and more

My first exposure to the Reference Anniversary came at Audio Research last summer. It was memorable. Normally one must assess a demo system in its entirety, because of the number of variables involved: speakers, electronics, sources, and cables all arrayed in a room whose inherent sound is completely unknown. However, I have heard Audio Research's system many times, so I was familiar with its general personality and capabilities. It always casts a wide and especially deep soundstage, and it displays abundant tonal color and three-dimensional presence. But during my visit last summer there was simply more: more width and depth, more color and presence, more dimensionality, more air, more bass weight and power. This time, the Reference Anniversary was part of the system, paired with Reference 210 monoblocks -- amps whose sound I know well. While it seemed impossible, I truly believed I could discern the Reference Anniversary's contributions, mainly because the presentation was supercharged, reaching levels of spatial and tonal reality that were at once startling and then mesmerizing -- not to mention beyond anything I had ever heard in Audio Research's demo room.

In my system many months later, the Reference Anniversary picked up where it left off in Minnesota. Before it arrived, I had been listening to the Reference 5 and hearing what was certainly as close to the Reference Anniversary's absorbing splendor as possible. The scale, dimension, tonality and power were apparent -- and then more apparent once the Reference Anniversary made its debut. Immediately obvious was an overwhelming sense of composure, the music coming from a deeper point of origin. The backdrop was blacker for sure, signaling that the Reference Anniversary had very low noise. But along with this was a sense of calm, whose elements included a preternatural lack of grain and effortless dynamics. Transients achieved maximum acceleration in an instant, then faded to utter blackness. Instrumental and vocal textures were vivid and tangible, imparting a view of the music that was holographic and densely physical at the same time.

Saying that the Turtle Island String Quartet "had presence" on its CD of jazz standards, A Love Supreme: A Tribute to John Coltrane [Telarc CD-80684], would certainly be accurate, but it wouldn't fully capture the Reference Anniversary's abilities. It's not just presence -- the sense that the musicians are in the listening space -- but also supreme delineation. Tonality was saturated, each instrument's voice genuine and distinct. And all of this happened with dynamic alacrity that was closer to that of live music than I've heard from any preamp. The small dips and rises in volume as the stringed instruments probed the opening to Coltrane's masterwork were equally lucid. At once the strings were individual entities, and then they conveyed a sense of massed power that was stunning.

I'm probably not describing this well, or describing it in a way that is true to the experience of hearing it. It's one of many ways the Reference Anniversary defies proper explanation, perhaps because the audiophile vocabulary is simply inadequate. The bass was more straightforward, offering control and authority along with bloom and weight. It was naturally rendered -- neither akin to a depth charge nor a sledgehammer, the entire bass range pouring forth with realistic pace and effortless dynamics. The dynamic range of bass frequencies is easy to overlook amidst the sort of low-end reach and grip the Reference Anniversary can summon, but it's vital to its achieving power that's reminiscent of live music.

The Reference Anniversary portrayed acoustic and electric bass with a litheness that was unmatched among preamps I've heard, either tube or solid state. Ray Brown's playing on the LA 4's Pavane Pour Une Infante Defunte [East Wind EW-10003] is, first and foremost, profusely detailed. This is a late-1970s direct-to-disk LP whose sound, I'm convinced, will be astonishing by the standards of a hundred years from now, and the music is interesting as well. When the strings are tapped or thumped, there is no bloat or overhang -- again, this is a special recording. The Reference Anniversary mined every bit of it. Brown's playing displayed the sort of elastic energy that lesser recordings just don't capture -- and lesser preamps don't communicate. The midbass was ripe and nimble, while the lowest reaches were defined by the recording, not the Reference Anniversary. Bass depth and definition may be weak points of many tubed preamps, but they're in the discussion of the Reference Anniversary's strengths.

As are the things that Audio Research electronics traditionally do well -- like conjure an enormous, ethereal soundstage or rise and fall dynamically in a uniform and realistic fashion. The Reference 5 and Reference 3 before it were champs at populating the sonic vista with instruments and their decay trails, and the Reference Anniversary does this even better, further elongating the soundstage front to back and side to side. And when it comes to conveying the totality of dynamic range, the Reference Anniversary was again the best I've heard. It both soared from soft to loud, beginning from a vanishing point of noise, and reacted instantly to small shifts in volume from singers or individual instruments, achieving all this with supreme dexterity. The SACD of Count Basie's classic on the Impulse! label, Count Basie and the Kansas City Seven [Impulse!/Analogue Productions CIPJ 15 SA], is a challenging test of both a component's resolving power and low-level dynamic prowess. The Reference Anniversary dug deeply into the recording, revealing all of the fine detail of the playing while also conveying a majestic sense of the band's mass and the space in which it was playing. Even at low levels, when the music begins to recede into the noise floor, the Reference Anniversary preserved proper proportion, and it did this as well as the very quietest solid-state preamps.

Arriving as it did, in the midst of my listening to the Reference 5 ($11,995), the Reference Anniversary made this review a drawn-out comparison between the two preamps -- at least initially. It's only natural to compare the old king to the new, and before the Reference Anniversary showed up, I would have considered its level of performance a fantasy. The Reference 5 is its own product, not simply a near analog of the Reference Anniversary. Its perspective is a bit more forward, and its balance leans a bit more toward the treble. At first listen, it sounds brighter than the Reference Anniversary, but this is replaced by an understanding of the latter's composure, which is most easily discerned from the eerie way the treble settles. Moving downward, the Reference Anniversary's midrange is considerably more dimensional, and its bass is better realized -- more substantial in the midbass and more fleet in terms of rhythmic drive.

When it comes to the traditional strengths of Audio Research products, it's hard to say that a preamp sounds bigger than the Reference 5, but the Reference Anniversary does. It's hard to say that a preamp sounds more dynamically complete than the Reference 5, but the Reference Anniversary does. It builds on the Reference 5's considerable strengths and begins to lap the rest of the field. Hearing it is mandatory if you're shopping in its substantial price range -- and educational if you're not.

Cruel April -- for a few more days

The one hitch to ownership of a Reference Anniversary, aside from its price, is availability. Audio Research will take orders only through April. Reference Anniversary preamps will roll out of the factory for a few months after that, as those final orders are filled, but once April ends, so does your chance to own one of these beauties. It's inevitable that someday a better preamp will come along, probably from Audio Research itself. But until that time, the Reference Anniversary will be a standard of sonic performance and a piece of audio equipment whose existence truly is cause for celebration.

Price: $24,995
Warranty: Three years parts and labor.

Audio Research Corporation
3900 Annapolis Lane North
Plymouth, Minnesota 55447
(763) 577-9700

Associated Equipment

Analog: TW-Acustic Raven AC turntable, Graham B-44 Phantom Series II and Tri-Planar Mk VII UII tonearms, Dynavector XV-1s (stereo and mono) and Audio-Technica AT33EV cartridges, AudioQuest LeoPard phono cable, Allnic Audio H-3000V and Audio Research Reference Phono 2 phono stages.

Digital: Audio Research Reference CD8 CD player, Ayre Acoustics DX-5 universal player.

Preamplifiers: Audio Research Reference 5.

Power amplifiers: Audio Research Reference 110 stereo amp, Lamm Industries M1.2 Reference monoblocks.

Loudspeakers: ProAc Response K6, Thiel CS3.7, Tidal Sunray.

Interconnects: AudioQuest William E. Low Signature, Shunyata Research Aeros Aurora-IC.

Speaker cables: AudioQuest William E. Low Signature, Shunyata Research Aeros Aurora-SP.

Power conditioners: Essential Sound Products The Essence Reference, Shunyata Research Hydra V-Ray Version II.

Power cords: AudioQuest William E. Low Signature, Essential Sound Products The Essence Reference, Shunyata Research CX-series (various).

Equipment rack and platforms: Silent Running Audio Craz˛ 8 equipment rack and Ohio Class XL Plus2 platforms (under Lamm M1.2 amps), Harmonic Resolution Systems M3 isolation bases under digital gear.

Equipment rack, platforms and accessories: Billy Bags equipment rack modified with a 4" maple platform, Stillpoints Ultra isolators, Stillpoints Component Stands, Furutec GTX D-Rhodium AC outlet.