Audio Research • Reference 5 SE Preamplifier

by Dennis Davis | September 8, 2012


Line-stage preamps are too often the Rodney Dangerfields of high-end audio components. They get no respect, no respect at all. Audiophiles are always trying to find ways to do without them. Remember the passive preamplifier craze, when hope sprang eternal that all you needed was a 10K-ohm potentiometer connected to a series of line-level outputs? And, of course, any fool with a soldering iron and a kit catalog could cobble one of those together and connect it to a CD player that touted enough output to drive an amplifier. Voila! A mighty blow was struck against those greedy equipment manufacturers, the ones that had been forcing you to buy an extra box just to connect your source components and switch between them.

Although most agree that the passive ploy never produced the best sound, the constant suggestion that you’re not really necessary can take its inevitable toll. When everyone is out to get you, you tend to lie low, keep your mouth shut, and just try and get on with your job. And if you are a line stage, that job is to supply attenuation, to lower output impedance and to provide switching for line-level sources. You can forget trying to draw attention to yourself. While few still accept the notion that the line stage is dispensable, it remains in many ways the least sexy link in the audio chain. When it comes to good looks, turntables and speakers offer far more interesting design and cosmetics than a box of electrical circuits, tubes and knobs. And nobody would suggest that any other part of the audio chain could be gotten rid of. You’ll often read critics describing the effect of a line stage almost as if it has been eliminated, suggesting that the unit is so neutral it "just gets out of the way" and "lets the music through" -- as if the best line stage is no line stage at all.

However, this cliché has been applied to so many different-sounding line stages that it has become quite meaningless. How can two different-sounding units each sound like nothing at all -- unless there are two different versions of nothing? And more to the point, what is the sound of nothing?

In November of 2011, Audio Research (ARC) announced that it was replacing its Reference Phono 2 and Reference 5. However, they did not change the model designations, just adding the "SE" suffix to the existing nomenclature, signaling that we should expect refinements rather than major restructuring of these already very successful products that garnered nothing but rave reviews.

I was sufficiently impressed with the Reference 5’s performance, and particularly with its value, to add it to my system after abstaining from earlier Reference line stages. It really was an outstanding unit, yet it never caused me to fall head over heals in love with it in the same way I did with the Reference Phono 2, which was so far ahead of anything in its price range. It traded punch for punch with competing phono stages costing far more while doing some things a little better, capturing my imagination in a way few components had before. I, along with Roy Gregory, enthused about it in issue 72 of Hi-Fi+, back in early 2010. We were hardly alone in our admiration; Tim Aucremann sang its praises for The Audio Beat. The Reference Phono 2 not only came to the dance, it stole the hearts of the handsomest suitors. The Reference 5, on the other hand, stood in the background, quietly attracting attention without flaunting itself.

Audio Research later proved that it could do even better than the Reference 5 when it introduced the Reference Anniversary in April 2010. This was pretty much twice the line stage as the Reference 5 -- twice as many chassis and twice as expensive, ramping it up well into the cost range of the more obscure, tweakier (and not necessarily as consistent) contenders from a handful of our more esoteric companies. But the Reference Anniversary was a special edition produced for a single year, and now it’s gone. I was never tempted by it because its two-box format is anathema to my space-limited audio aesthetic. Mono amplifiers are one thing, but two-chassis phono and line stages and CD/SACD "stacks"? Not for me.

Remarkably, ARC has solved the dilemma of sacrificing sound to compact convenience by incorporating many of the design features of the Reference Anniversary into the SE version of the Reference 5. Even better, the cost of the SE represents only a modest increase over the original. The Reference 5 SE is priced at $12,995, making it $1000 more expensive. And for owners of a Reference 5, the truly good news is that existing units can be upgraded for $2500. The bad news is that because of high demand and parts delays, Audio Research is handling existing upgrade requests for now and hopes to resume taking new requests in the fall.

From the outside, the SE looks pretty much the same as the original Reference 5, except that the button array has changed to a new style. Also, the Plexiglas top cover, optional for the Reference 5, is now standard -- and that’s a good thing. ARC knew from the beginning that the Plexiglas cover sounded better than the metal, but offered both in anticipation of customer resistance to the Plexi version. Apparently there was no push back for metal, so the obvious decision was to dispense with it altogether. The changes under the lid are more extensive and largely mirror the improvements incorporated into the Reference 150 amplifier, released shortly ahead of the Reference 5 SE: a doubling of the power-capacitor complement, new Teflon coupling capacitors, and some other component replacements.

What to expect from a line stage other than the obvious volume, switching and coupling functions? To answer that question, you need to consider what music is and how it translates to reproduced sound. At its most fundamental, music is an art form that imposes structure upon a series of sounds and not-sounds (silence). Timed sequences are organized into melody, rhythm and harmony, each having its own relationship to time, and those three fundamentals are piled together to form a complex layer of events that provide a texture to music. That structure is a matter of timing, or the sequencing of events. Like visual art, music has dimension, but unlike visual art that has a spatial dimension, music has a temporal dimension -- one dictated by time. It’s all about time, as so many musicians have reminded us. Whether its Dave Brubeck’s Time Out, Sonny Rollins’ Newk’s Time or Joe Morello’s Its About Time, music’s most fundamental attribute is time, and unless time is preserved in the recording and playback electronics, the result will be disappointing.

Fundamental to this relationship between music and reproduced sound is the ability of a component to conjure a soundstage. I’ve never understood the idea that the soundstage is unimportant just because a supposedly prime seat at a symphony hall, for instance, might produce flat, lifeless sound. If the engineer captured stage depth in the recording, your electronics should be able to reproduce it. Whether the hall acoustic captured by the recording engineer is an exact duplicate of what you would have heard in that hall unaided by modern technology is a discussion best left to recording-engineer reviews. I’d also point out that you don’t sit where the microphones are. A line stage should not impose a sense of three-dimensional space on otherwise flat, lifeless recordings, but unless your line stage can preserve the timing captured by a recording engineer and preserved by the mastering engineer, subtle distinctions become blurred, and that blurring tends to collapse the three-dimensional construct we call a soundstage.

One of the hallmarks of Audio Research products is their ability to throw a generous soundstage. The Reference 5 was no slouch in that department, but the Reference 5 SE starts from that point and expands upon it in quantity and, most important, quality. I started the process of evaluating the 5 SE by eschewing use of the companion piece, the Reference Phono 2 SE, in order to segregate the impact of each unit. I ran the unit in with aid of the burn-in track of the Sheffield Labs/XLO test and burn-in disc for about 200 hours and then began listening to several CDs of small-scale music that I knew well, like the Heartworn Highways compilation [Loosemusic VJCD 167] and Ella and Louis [FIM UHD 045] -- discs I had listened to with the Reference 5 while the SE was breaking in.

It took only moments to recognize that I was hearing something quite remarkable from the latest version of this line stage. It wasn’t that the soundstage was blown up to greater proportions (although it did expand a bit), but it was the way the Reference 5 SE organized the information within that stage. I was hearing nuances and dimensions of the music that hadn’t been there hours before. Townes Van Zandt’s "Waitin’ ‘Round To Die" sounded more than ever before like it was recorded sitting around a table in a country shack, complete with the noise wafting in from outside. Boundaries became more apparent and the micro-dimensions were redefined; individual events within the soundstage enjoyed tightened focus and became better defined in space.

If the Reference 5 SE could redefine space this well on a small scale, how would it fare on something really complex? Because of the recent Blu-ray release of one of my childhood favorites, Journey to the Center of the Earth, I had been listening quite a bit to the film soundtrack excerpts on The Fantasy Film World of Bernard Herrmann LP [Decca PFS 4309]. With an orchestra of woodwinds, a large percussion section and five organs, this recording has a lot to sort out and is a torture test for any system to make sense of (avoid the London pressing, which is itself a torture, system notwithstanding). Some of the more demanding sections can sound muddy, even on the best of systems, and switching over to the Reference 5 SE really grabbed my attention. Yes, it sorted out the muck of the five organs, but then as the recording segued into The Seventh Voyage Of Sinbad soundtrack, with its "Duel with the Skeleton," the SE’s ability to sort out and lock in the timing had skeletons dancing in my listening room as never before.

The Bernard Herrmann LP also emphasized the improvements that the Reference 5 SE brought in the frequency-extension department. Bass was better defined and more dynamic. The improvement in top-end extension was also obvious, with more shimmer to strings and high percussion sounds, an impression confirmed with my go-to string recording, Salvatore Accordo’s Diabolus In Musica [DGG 477 6492].

Piano also shone with the Reference 5 SE. Yevgeny Sudbin’s collection of Chopin Nocturnes, Mazurkas and Ballades on BIS SACD [SACD-1838} is a pretty outstanding piano recording and sounds good on almost any system. The 5 SE, however, allowed the recording to breathe, with more air around the notes, locking the sound in tighter than the standard Reference 5 and leaving open the space around the notes to hold the sound of the decay and effect of the room reflections. The new information that showed through with the 5 SE had me searching the Internet to confirm what St. George’s in Bristol, England, (where the recording was made) looked like. That’s the kind of detail I want my equipment to dig out of the recording -- new information that gives insight into the performance and venue.

What this collection of attributes added up to more than anything was a sense of forward movement, of life and energy. This is a hard thing to quantify or measure, but it increasingly imposed itself on my listening impressions over time. Which brings us back to the issue of time. Whether the collection of virtues -- better articulated bass, extended high-frequency performance, dynamic punch and the ability to re-create an extended and well-defined soundstage -- is just a list of separate attributes or whether their combination results in a better sense of musical propulsion and rhythmic accuracy can be debated. But as each of these attributes is fundamentally related to the timing of events, my sense is that there is an additive function. Whatever the answer, the Reference 5 SE could be said to be all about time; the improvements over its forerunners in sorting out temporal elements were significant and made it a much-improved line stage.

While the Reference 5 was an accomplished line stage and among a handful of the best available, the SE version added an expansion of performance that propelled it into a class against which others are measured. I have heard of one dealer who lived with the Reference Anniversary line stage since its inception, but after having the Reference 5 SE in-house for a while, he sold off his Anniversary and kept the 5 SE, which he preferred not just for the price, but also for the performance. As with the Reference Phono 2 when it first came out, I have fallen hard for the Reference 5 SE, and that’s a first for a line stage.

Price: $12,995
Warranty: Three years parts and labor.

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

Associated Equipment

Analog: VPI TNT-6 turntable with rim drive and SDS speed controller, VPI 12.7 tonearm, Lyra Skala and Titan Mono cartridges, Koetsu Coral cartridge, Audio Research Reference Phono 2 and Reference Phono 2 SE phono stages.

Digital: Audio Research Reference CD7 CD player.

Preamplifier: Audio Research Reference 5.

Power amplifier: Audio Research Reference 150.

Loudspeakers: Avalon Acoustics Transcendent.

Interconnects: Nordost Valhalla.

Speaker cables: Nordost Frey.

Power conditioners: Quantum QBase 8 and QX4.

Power cords: Nordost Valhalla.

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.

The Reference Phono 2 SE

Audio Research released the Reference Phono 2 in mid-2009, priced at $11,995, and it was an immediate success, setting new performance and convenience standards for a top-end phono stage. The Reference Phono 2 produced outstanding dynamic impact, a delicate yet detailed upper midrange, a deep, refined bottom end, a great soundstage and a low noise floor. I waited a couple of months, living with the Reference 5 SE on its own before introducing the companion, upgraded phono stage into the mix. Audio Research introduced essentially the same changes to the Reference Phono 2 SE as those described for the Reference 5 SE, and they increased the price by the same $1000. Like the Reference 5, the Reference Phono 2 can be upgraded, but for $2000.

So what you have now is the same outstanding phono stage with among the most flexible set of virtues on the market: variable equalization curves, numerous loading options (including one that you can have custom set at the factory) and two gain choices, all of which are switchable via remote control, with the same doubled-up power-supply capacitance, Teflon coupling caps and other circuit modifications as the 5 SE.

Predictably, the improvements reflect the same DNA as those heard in the line stage. All the attributes of the original phono section remain, but many of them are turned up a couple of notches. The improved bottom and top ends, along with the finely structured soundstage are dialed in even more deeply.

But the improvements were more than cumulative. Like using the same cable throughout the system, there is an advantage to using electronics that were designed together. You are not working against the weaknesses in your system, using the strengths of one component to balance the problems inherent in another. When pairing designs works just right, as it does with this matching, the result is more than just the sum of its parts. With the two SE sections in tandem, the differences among cartridges became much more apparent. I found myself spending more time comparing not just performances but what different cartridges did to those performances, digging out treasures from my record collection I’d not touched in years -- and in some cases, decades. Likewise, the improvements brought about by tweaks to the system, such as the marvelous Stillpoints LP Isolator, were more obvious with the new units, adding value to that investment too.

When a new component sparks such a flurry of rediscovery, something very special is going on.

-Dennis Davis