Audio Research Reference Two preamplifier Page 2
Like a plush, comfortable chair, the Ref 2 put a soft cushion around the music's bottom end—not so cushy that the deep bass sank in and disappeared into the foam, but enough to add a warm, comfortable, enriching envelope. Sort of like tube gear in the days of yore, but with no disruption of the timing of bass events. If that sounds to you as if the bass was slightly fat, fair enough—but the Ref also added a whompin', stompin', explosive bass dynamic that was downright nuclear in its attack. Soft and mushy this bass wasn't! (Thank you, Yoda.)
The net effect was big, dynamic, rhythmically lithe bass that was just slightly larger than what was in the signal fed to the Ref 2. No doubt with some loudspeakers this might lead to overload or oversize, but through the Sonus Faber Amati Homages, which do not offer tight, overdamped bass to begin with, the results on great bass-rich recordings (like Davy Spillane's Atlantic Bridge) were always musically effective. Bass never sounded smothered, syrupy, uncontrolled, or unnatural. Rock-band kick drums on great recordings like The Clash's Sandanista (British CBS FSLN 1), while rich and full-sounding, had plenty of slap and texture without becoming rhythmically or tonally soggy.
This sort of rich bass performance would probably stick out like an unwanted hangnail if it wasn't so well connected to the higher registers. The Ref 2's performance above the bass was also subtly more vivid, warm, and harmonically enriched than the incoming signal, but only slightly so: full bloom, no stem rot. The result was a coherent, fertile, BIG picture—the fundamental opposite of the best solid-state preamps, like my reference, the Ayre K-1x. To some ears and with some associated gear, such gear can sound overly damped below and knife-sharp-thin on top, just as, to some, the Ref 2 will sound overripe. That's why there's more than one high-end audio manufacturer, and why some experienced ears prefer Krell, others Conrad-Johnson, though the two companies' sounds are at opposite ends of the sonic spectrum.
I borrowed a friend's 1980s-vintage Audio Research SP11, and it sounded far less "together" than the Reference Two, with punched-up upper mids, a thin "hot" band in the treble, a noticeable warm zone in the midbass, and generally far more of a "hi-fi" sound. Highly regarded in its day, the SP11 can't compare to ARC's latest effort.
Compared to the fresh-out-of-the-box Ayre K-1x (updated from the K-1 with the new power supply), the Ref 2's top end was ever so slightly soft, taking a bit of the metallic edge off of cymbals and the hard ringing of bells. One of my favorite test tracks for this is John Renbourn's exquisitely recorded Sir John A lot of (Transatlantic TRA 167), which features a fabulous acoustic guitar and crystalline finger cymbals and glockenspiel. The Ref 2 took a bit off the top-end extension and "ring" compared to the K-1x, but not enough to harm the astonishing clarity and illusion of reality of the percussive events, or to slow or soften the attack of Renbourn's guitar, which sounded slightly more rich and woody through the Ref 2.
That compliments both products, which fall just to either side of the "neutral" line. The Ref 2 sounded fast. It kept up with the K-1x, while sounding somewhat richer and more fully fleshed-out. This is not to say it sounded better or worse; it all depends on your taste and associated gear.
The Reference Two was quiet for a tube amp, with just a trace of thin white noise when no signal was fed it—a far narrower spectrum than the usual "tube rush." Still, there was a slight price to pay for the raised noise floor compared to the best solid-state preamps: on classical recordings, lower resolution of very-low-level information such as back-of-the-stage reverberant events; and on pop and rock, a de-emphasis of electronic studio effects. The latter was actually a blessing; most of this studio detritus is not supposed to be so obvious in the mix, and isn't with the kind of gear it's usually played through.
Dynamics at both ends of the scale were among the best I've heard, rivaled only by the Sharp SM-SX100 digital amplifier: explosive at the loud end, nuanced and capable of revealing fine gradations below. The Ref 2 never unraveled on orchestral crescendos, maintaining spatial and tonal integrity. Its rendering of small-scaled, delicate dynamic movement gave life to some recordings that previously had seemed to fade into a glaze as the musical detail descended in level. The Reference Two delivered this sensation of living music even at relatively low volume levels.