Aspiration. Audiophiles and reviewers have it in spades. We aspire to extract ever more from our audio systems: higher levels of performance, greater realism, more emotional connection with the music. Audiophiles are derided (often with justification) for the upgrade merry-go-round that can result from an unchecked conviction that the sound can always be improved; but if we keep system synergies and overall balance in mind, the thoughtful incorporation of new components can indeed give us more of what we aspire to.
But an aspiration for “ever greater” is not limited to the buyers’ side -- “I can do it better” has been the motivating mantra for most makers of high-performance audio. Moreover, few manufacturers could long survive without continuing to push themselves to extract more from their designs. The quest for improvement, coupled with sound business practices, enables brands to thrive through decades.
A drive to produce better-sounding audio gear has been part of the ethos of the Audio Research Corporation since its founding, by William Zane Johnson, more than four decades ago. ARC reached a high note in 2010, when it celebrated its 40th anniversary by releasing a two-box preamplifier, the Reference Anniversary -- one of those rare components that won great acclaim during its single year of production, and has achieved the status of a legend among jaundiced journalists and even industry competitors.
ARC has spent the years since then applying the lessons learned from the Reference Anniversary -- greater power from and improved regulation of the power supplies, better parts -- to the SE upgrades of its Reference 5 preamplifier and Reference Phono 2 phono preamplifier, as well as to a series of power amplifiers optimized for KT120 and even KT150 output tubes. Nevertheless, the call of ARC’s worldwide dealer network and those audiophiles who missed the Reference Anniversary’s window of opportunity, and ARC’s own aspirations to raise the bar higher still, have resulted in the development of the Reference 10 tubed line stage ($30,000 USD), the first regular-production two-box preamplifier from ARC since the SP11 Mk.II, in the late 1980s. Does the Reference 10 live up to ARC legend?
Familiar yet different
My review sample of the Reference 10 arrived in two big shipping boxes, each about 25” square by 15”H; the one for the control unit weighed about 35 pounds, the power-supply 50 pounds. Inside, each component was wrapped in a heavy plastic bag and secured with thick, pressure-fit polystyrene. Smaller containers held the Ref 10’s complement of 12 tubes and 20A power cord, a pair of umbilical cords to separately link each channel of the dual-mono power supply to the corresponding channel of the preamp, a screwdriver, a pair of white gloves, a guide for installing the tubes, and a comprehensive instruction manual -- all in all, more protective and luxurious packaging than was provided with ARCs past products.
Those conversant with earlier ARC Reference preamplifiers will find familiar the Reference 10’s large cases (each is 19”W x 7”H x 15.5”D) with their front-panel rack handles -- until they try to heft them. Whereas the Reference 5 SE and its predecessors seemed slightly less substantial than their size suggested, each half of the Ref 10 is much more solid: The control unit weighs 23.6 pounds, the power supply 37.7 pounds. The side panels and bases of the Ref 10 cases seem to be as thick as the Ref 5 SE’s front panel, with the Ref 10’s front panels looking to be about 50% thicker still. The result is a component with significantly more heft, rigidity, and inert qualities. The thicker panels also have a milled-from-solid look, and a precision fit and finish that elevate them above the more utilitarian, lab-gear feel of past ARC products -- a transition that has further evolved with the new GS models.
The second obvious visual break from the past is the Reference 10’s asymmetrical front panel. The color-coordinated handles remain, but dominating the left half of the faceplate is a glorious 7” touchscreen. Centered in the right half is a large rotary volume control. Above that single knob is the ARC logo, below it the Ref 10’s only two buttons: Power and Mute. While it lends the Ref 10 a more authoritative and tactile experience than its predecessor, I do wish the microprocessor-driven volume control spun freely instead of being a rotary toggle: turning it about 15° to right or left increases or decreases the volume, or adjusts the balance once that setting is activated via the touchscreen. Nevertheless, this knob satisfactorily performed its function, and is finally on the “right” side (flouting industry convention, ARC’s volume controls were always on the left side of the front panel). However, the real advancement is the touchscreen, which brings operation and customization of ARC components into the 21st century. Rather than the big green screens that for years defined ARC Reference models, the touchscreen has a wide array of color choices available for both foreground and background, and six levels of intensity (including Off).
Through the display, the Reference 10’s seven inputs -- six audio, one theater pass-through -- can be configured, customized, and named. Out back, the connection to each input can be balanced (XLR) or single-ended (RCA), but it’s through the touchscreen that you designate your choice. Each input can be further customized with a source name (e.g., Ref DAC, Ref Phono 10, etc.), and gain offset (to adjust for and minimize differences in source output voltages). Also via the touchscreen can be selected controls for balance, mute, and phase inversion; any choices made are clearly indicated. And a mere touch away is the tube-hour counter. The 6H30 tubes ARC supplies with the Ref 10 have an estimated life of 4000 hours, though word on the street recommends that they be replaced after 3000 hours (2000 hours for the two 6550s). All touchscreen controls are duplicated on the Ref 10’s hefty remote control. This new level (for ARC) of user interface and system integration and customization leapfrogs the Ref 10 to the front of the line of statement-level tube preamplifiers.
ARC’s specifications for the Reference 10 include: a frequency response of 0.1Hz-200kHz, +0/-3dB (balanced output into 200k ohms); distortion of less than 0.006% at 2V RMS (balanced output); input impedances of 120k ohms balanced, 60k ohms single-ended; output impedances of 600 ohms balanced, 300 ohms single-ended; crosstalk of -80dB or better at 1kHz; and noise of 109dB below 2V RMS output.
Using the included screwdriver and installation sheet, I found detaching the cover and inserting the tubes a snap -- each tube and its corresponding socket are individually numbered. Four 6H30P dual-triode tubes per channel go into the control housing, while the power supply uses one 6550C and one 6H30P tube per channel. In the power supply, the left and right channels are identical and separate, ensuring that, following the 20A IEC input socket, the Reference 10 is a true dual-mono system. High-quality devices abound; for the circuit-board itself, ARC has eschewed the ubiquitous green fiberglass for a large expanse of dark-tan material known for its superior mechanical and dielectric qualities. The elegant, fastidious layout of the Ref 10’s interior earned from me greater respect for and confidence in ARC.
After I’d installed the tubes and reattached the translucent acrylic cover, it was time to place the Reference 10’s enclosures on their wide, well-ventilated shelves -- yes, unfortunately, two shelves, which is possibly the biggest downside of a two-box device: shelf space can be expensive, especially if, as I do, you have a rack from Harmonic Resolution Systems. Next up were attaching the power cable to the power supply, then the two cases with the left- and right-channel umbilicals. As there are two sets of Main outputs as well as a Record Out option, each configurable for balanced or single-ended operation, I completed the connection process with balanced interconnects to my monoblock amplifiers from a Main output on the Ref 10, and to my Ayre Acoustics QA-9 analog-to-digital converter via the Ref 10’s Record Out pairing, for needle drops.
Pressing the Power button starts the Reference 10’s warm-up process, which lasts about 40 seconds. During that time, messages appear on the touchscreen: a Loading page, followed by an ARC page, then an image of the Ref 10, and, finally, the main control screen, with the preamp’s last-used input active but with Mute engaged. Following the instructions in the user guide, I named and adjusted my inputs, and selected for display understated black letters on a light blue background, to complement the blue LEDs of my black Brinkmann turntable and Ayre digital source components.
Knowing that ARC Reference products usually need several hundred hours of use before revealing their full potential, I began with a few weeks’ worth of nearly constant play of computer-audio playlists. To ensure that both of my primary inputs received fairly equal treatment, I swapped input cables halfway through this period -- getting several hundred hours of throughput from my vinyl source would have taken too long.
At last, it was time to hear if the Ref 10 could live up to the hype. Given its dual-mono architecture, supercharged power supply, more robust casework, and high parts quality, I expected the Reference 10 to surpass the performance of my Reference 5 SE. First impressions can be revealing, especially in a stable, well-known system and room, and, after the Ref 10 had been thoroughly broken in, I was not disappointed. Within a month, I’d decided that the Ref 10 would be replacing the Ref 5 SE as my reference preamp in my big rig, and --
We interrupt our regularly scheduled programming . . .
Just as I was getting the full flavor of the Reference 10’s capabilities, we moved. Now, instead of a largish family room in an apartment, my big rig occupied a smaller but dedicated listening room in a house. But before I could return to an honest analysis of the Ref 10 in the context of my other gear, I had to sort out the new room itself. The downside was time lost, the upside a listening environment with greater potential and, in the case of the Ref 10 (and the sublime Brinkmann Balance turntable, review forthcoming), time regained: I ended up with a much longer period in which to investigate this exceptional product.
The evaluation of any audio product tends to begin with an overly analytical period in which favorite demo and test tracks are played to figure out precisely what is going on. Though in most cases this is a necessity, there is nonetheless a disconnect between how one responds to such an artificial situation and how one responds to the music -- of which the reproduction for pure enjoyment is the reason we do any of this at all. I’m an album listener, not a track hound. Whether a listening session consists of spinning LPs or streaming digital files, I tend not to create playlists, or to jump from track to track or from performer to performer. Rather, I select the album I’m in the mood for, then play it from start to finish. Having had the Reference 10 as a constant companion for well over a year, I found that it was the musical forest it presented, rather than individual trees, that most impressed me. Yes, it handled with aplomb all items on the audiophile checklist: soundstaging, gravitas, nuance, dynamics, etc. But when music was the focus, it pulled me in and kept me there. And that’s what it’s all about.
I never tire of Neil Young’s Massey Hall 1971 (LP, Reprise 43328). In my system -- especially as it has coalesced over the past several years -- it always produces visceral “time machine” qualities. There’s something special about well-recorded live performances, and here -- a lone performer onstage, connecting voice, instrument, auditorium, and audience -- the recording catches the magic. Yet, since introducing the Reference 10 into the system, it’s “The Needle and the Damage Done” that overwhelms me every time. I’ve read all about the devastation heroin has wreaked on multiple generations of artists, from jazz to rock to the visual arts. But hearing Young’s voice as it drips pain and anger in helpless lament through the Ref 10, it was no longer a detached “knowing about.” Rather, I felt an empathic connection between me and one who had lived in the midst of that cancer, and whose friends fell by the wayside. In those moments, I felt Young’s pain and loss as my own; it became personal -- more than it had been before the Ref 10’s arrival.
Listening to Johnny Hartman’s I Just Dropped By to Say Hello (16-bit/44.1kHz AIFF, Impulse! A-57), I realized I couldn’t recall having heard the microphone overloading moments after Hartman begins singing “In the Wee Small Hours of the Morning.” At a Consumer Electronics Show several years ago, I played the first 30 seconds of this track in at least two dozen exhibitor suites: the way a system handles this production flaw can tell quite a story. In systems whose bass energy is too lean, this mid-frequency blemish can be so pronounced as to be quite irritating. But through systems that produce a soft-focus sound that lays a silken sheen over everything, it can be hard to hear at all. The best systems don’t cover up the failing, while keeping the liquidity of Hartman’s baritone front and center. I’m greedy -- I want all the detail embedded in a recording, and I want to be captivated and gripped by the story told by the performers and the recording and mastering engineers. Sure enough, when I replayed the track, this time focusing on the artifact, there it was in all its detail -- but reduced to musical irrelevance as Hartman sang on without a hitch. With the Reference 10 in control, what dominated my attention was the music itself, not the playback equipment or deficiencies in the recording.
Tubes vs. tubes vs. solid-state
An interesting comparison can be made between the Reference 10 and the two reference devices that preceded it in my system: ARC’s Reference 5 SE ($13,000) and Ayre Acoustics’ KX-R solid-state preamplifier ($18,500, discontinued). When I compared the original ARC Ref 5 with my then reference, the KX-R, I was seduced by the emotional impact of the tubed model, but nonetheless kept the Ayre -- I considered it to be an intellectually perfect preamplifier for its ability, in analytical deconstruction mode, to best every test I threw its way. However, when the Ref 5’s SE upgrade came along, and with it a bigger soundstage, greater dynamic drive, and less obvious editorializing, I decided, without regret, to switch to the more emotionally satisfying ARC. (My daytime, all-digital reference system benefited from being the KX-R’s new home.) And as the sound quality of the Ref 10 surpassed that of the Ref 5 SE in every regard, to the point of essentially pure neutrality (rather than tube editorializing), my decision to make another upgrade was easier than any I can recall.
We interrupt our regularly scheduled programming . . . again . . .
However, during this period Ayre released a major upgrade to the KX-R that transformed it into the KX-R Twenty ($27,500), a modification Jeff Fritz enthused about at length. I had my KX-R updated to Twenty status, and agree wholeheartedly with Jeff’s every observation. But there was one conclusion that Jeff’s KX-R Twenty review didn’t fully expound on: The whole of all the improvements the Twenty upgrade makes in the KX-R’s sound is much greater than the sum of its parts. The KX-R Twenty’s sound has not only a new robustness and solidity -- rather, it’s as if designer Charles Hansen had taken a page out of Dr. Frankenstein’s lab notes and brought his preamplifier to life! The emotional gulf between listening to solid-state and listening to tubes was greatly narrowed, if not completely closed. The Ayre KX-R Twenty sounds surprisingly like . . . the Audio Research Reference 10! Still, after schlepping the Ayre back home to my vinyl-dominated system for a head-to-head, I ultimately preferred to keep the Ref 10 in place -- though it was close to a toss-up.
As deserving as Audio Research’s Reference 5 SE proved to be during its long tenure as my primary reference preamplifier, the sound of the company’s Reference 10 is distinctly superior: more dynamic, even better at throwing a solid, expansive soundstage, and presenting the music against a quieter background. It also seems, to my ears, to be the more honest electronic device, though some will miss the euphonic editorializing the Ref 5 SE’s slight tube bloom can impose. To me, the result is clear: The ARC Reference 10 is one of the most thrilling, intoxicating, musically engrossing preamplifiers ever made. Congratulations to Audio Research Corporation for their aspirations and their execution. Kudos, too, for the introduction of a superior user interface, more attractive appearance, and tactile luxury.
. . . Peter Roth
- Speakers -- Vandersteen Model Seven
- Digital sources -- Ayre Acoustics DX-5 DSD Universal A/V Engine and QA-9 analog-to-digital converter; Apple MacBook Pro and CAPS Server Zuma
- Analog sources -- Spiral Groove SG2 turntable and Centroid tonearm; Brinkmann Oasis and Balance turntables with Tri-Planar U2-SE 10” tonearm; Lyra Kleos MC cartridges (mono and stereo); Audio Research Reference Phono 2 SE and Reference Phono 10
- Amplifiers -- Ayre Acoustics MX-R monoblocks
- Preamplifier -- Audio Research Reference 5 SE, Ayre Acoustics KX-R and KX-R Twenty
- Interconnects -- AudioQuest Wild Blue Yonder (analog) and Diamond (USB)
- Speaker cables -- AudioQuest WEL Signature
- Power cables -- AudioQuest NRG-Wild and NRG-100
- Power conditioner -- Shunyata Research Hydra Triton
- Supports -- Harmonic Resolution Systems MXR with M3X shelves
- Acoustic panels -- RPG: Diffractals, Omniffusors, BAD panels
Audio Research Reference 10 Preamplifier
Price: $30,000 USD.
Warranties: Three years parts and labor; 90 days, tubes.
Audio Research Corporation
3900 Annapolis Lane North
Plymouth, MN 55447-5447
Phone: (763) 577-9700