First, there is the little matter of break-in. I’ve never had components in my system that took as long as the ARC Reference Phono 10 and its companion piece, the Reference 10 Line Stage, did to settle down. The giant Teflon caps in both units take forever to start sounding their best—and by forever I mean several hundred hours of play. In the nonce, the Reference Phono 10 goes through so many permutations of fair, middling, and downright bad sonics that it would try the patience of Job. (Indeed, God should’ve given Job a Reference Phono 10 to break in instead of slaying his kine.)
Yes, the preamp finally gets all the way there. And, yes, I guess it’s worth the wait—if you want the best tube phonostage money can buy. But, trust me, for weeks after you purchase it you will rue the day you bought the Reference Phono 10 (and the Reference 10 Line Stage).
Second, there is the quandary of the Reference Phono 10’s input stage. As with all of its Reference phonostages, ARC offers two phono inputs, the gain of each of which is user-selectable (via ARC’s new touchscreen or its dandy remote control). With the input set to the low-gain setting (ideal for moving-magnet and high-output moving-coil cartridges), the entire phonostage is driven from input to output by eight 6H30 tubes (four per channel). For low-output moving coils, however, you must use the high-gain setting, which augments those 6H30s with select low-noise FETs in the input stage.
As has been the case in the past, there is rather a large gap between ARC’s low-and high-gain settings (51dB and 74dB) in the preferred balanced mode. Personally I’d like ARC to add a third, in-between setting of about 60-64dB gain to accommodate cartridges like my reference Clearaudio Goldfinger Statement, whose output voltage of 0.9mV is simply too low for the “low-gain” setting and too high for the “high-gain” one. Since there isn’t a “middle-ground” setting, listeners like me are forced to use the high-gain setting, which not only measurably increases harmonic distortion but also increases the potential for overloading those input-stage FETs on hard transients or big dynamic peaks (and though they don’t clip often, when they do you’ll know it because, unlike tubes, FETs do not clip “gracefully”). Using the high-gain setting also compels listeners like me to run the volume control of a linestage preamplifier in the 10-to-12 o’clock range (or the 25–45 range on the ARC Reference 10 Line Stage’s numerical readout).
Third, as incredibly lifelike as it now sounds in the bass and mid-range—and as substantially improved as it is in speed and dynamic authority (and this is the biggest improvement in dynamics and transient response I’ve yet heard from any ARC phonostage)—the Reference Phono 10 still isn’t quite the equal of a great transistor phonostage in bass grip and definition or in overall speed of attack. The Reference Phono 10 simply can’t do the Fender bass line of Lou Reed’s “White Heat, White Light” with the same unwavering control and focus of, oh, the Soulution 520’s built-in phonostage. Nor can the Reference Phono 10 reproduce transients, such as those Bartók pizzicatos in George Crumb’s Four Nocturnes, with the scary-real pistol-shot report of the Soulution preamp. I don’t want to belabor this point, as the Reference Phono 10 is much better in the bass and in dynamic range than any tube phonostage I’ve heard—and better in many ways (for which, see below) than the Soulution 520 or other first-rate solid-state phonostages. But, for the record, this slight difference in bass definition and transient speed is audible.
Fourth, for all its virtues the Reference Phono 10 is not as overtly detailed as a great solid-state unit. That’s because solid-state pre-amps, with their superior speed and lower noise, make transient details seem to “pop,” like fireworks against a night sky, where tube preamps with their superior steady-state tone seem to fold those same details into a more organic, three-dimensional whole.
Though both presentations can sound equally realistic, the fact is that switching from a great solid-state preamp to something like the Reference Phono 10 isn’t only a matter of hearing “this” or “that” more or less clearly; it is also a paradigm shift—from a sharper-focused, more analytical view of the music and the music-makers to a rounder, more holistic one. All I know is that when I first listened to the ARC Reference 10 duo, after months of using first-class solid-state, my jaw (and that of my friend Andre Jennings) dropped. Things suddenly sounded so right in timbre and so 3-D in imaging, it was astonishing. It was only later that I began to think about what may have been lost in face of all that had been gained.
The bottom line here is somewhat more complicated than usual. Though the ARC Reference Phono 10 unquestionably gets my highest recommendation and has become my new tube reference, it may not appeal to every kind of listener the way it does to me. Some may be frustrated by the break-in time it requires; some may be put off by its cost; some may prefer the naked clarity, superior speed, and tighter grip of transistors (even though the Reference Phono 10 comes closer to transistor-like clarity, speed, and grip than any tube phonostage I’ve auditioned).
This much I can say with confidence: If truth of timbre, bass and power-range weight and color, dynamic authority, and 3-D imaging on a vast 3-D soundstage are your foremost sonic priorities (and, on much music, I think the ARC’s three-dimensional, holistic presentation comes a bit closer to what I hear in life than solid-state’s somewhat flatter, more analytical one), then the Reference Phono 10 will be your preamp of choice. (And if you can’t afford it, there is always the superb Reference Phono 2 SE to fall back on.)
SPECS & PRICING
Frequency response: +/-.2dB of RIAA, 10Hz to 60kHz; 3dB points below 0.3Hz and above 300kHz
Distortion: Less than .002% at 1.0V RMS output (1kHz)
Gain: Selectable 51dB (Low), 74dB (High) at 1kHz (balanced)
Input impedance: 47k ohms and 100pF (unbalanced).
Selectable loads: 47k, 1000, 500, 200, 100, 50 ohms, and Custom
Phono equalization: (Selectable) RIAA, Columbia, Decca
Output impedance: 200 ohms unbalanced, 400 ohms balanced
Recommended load: 50k—100k ohms and 100pF (10k ohms minimum and 2000pF maximum)
Maximum input: 250mV RMS at 1kHz (680 mV RMS at 10kHz)
Tube complement: Eight 6H30P dual triodes, plus two each 6550C and 6H30P in power supply
Dimensions: 19" x 7" x 14"
Audio Research Corporation
3900 Annapolis Lane North
Plymouth, MN 55447
JV’s Reference System
Loudspeakers: Raidho C 4.1, Raidho C 1.1, Raidho D 1, Estelon X Diamond, MartinLogan CLX , Magnepan 1.7, Magnepan 3.7, Magnepan 20.7
Linestage preamps: Soulution 520, Constellation Virgo, Audio Research Reference 10, Siltech SAGA System C1
Phonostage preamps: Audio Research Corporation Reference Phono 10, Innovative Cohesion Engineering Raptor, Soulution 520, Constellation Perseus
Power amplifiers: Soulution 501, Siltech SAGA System V1/P1, Constellation Centaur, Audio Research Reference 250, Lamm ML2.2
Analog source: Walker Audio Proscenium Black Diamond Mk V record player, AMG Viella 12
Phono cartridges: Clearaudio Goldfinger Statement, Ortofon MC A90, Ortofon MC Anna, Benz LP S-MR
Digital source: Berkeley Alpha DAC 2
Cable and interconnect: Synergistic Research Galileo and Galileo LE, Crystal Cable Absolute Dream
Power Cords: Synergistic Research Galileo LE, Crystal Cable Absolute Dream
Power Conditioner: Synergistics Research Galileo LE, Technical Brain
Accessories: Synergistic ART system, Shakti Hallographs (6), A/V Room Services Metu panels and traps, ASC Tube Traps, Critical Mass MAXXU M equipment and amp stands, Symposium Isis and Ultra equipment platforms, Symposium Rollerblocks and Fat Padz, Walker Prologue Reference equipment and amp stands, Walker Valid Points and Resonance Control discs, Clearaudio Double Matrix SE record cleaner, HiFi-Tuning silver/gold fuses