The initial release of the Reference 6 SE, set for the early Spring of 2020, collided head-on with the COVID outbreak. As a result of shutdowns across the United States, some of Audio Research’s suppliers could not deliver promised parts on time and the start of production was impacted. Then, just as the review sample was finally due for delivery, I stumbled and broke my ankle, so I was unable to lift heavy objects for a few months. With so many unforeseen obstacles, it seemed that fate was conspiring to scupper this review. Was the long wait worth it? Given that unpleasant string of obstacles, I’ll admit to wondering just what might happen once I slit the packing tape on the large white carton that finally arrived. By opening the box was I risking further disappointment?

This was not as irrational a suspicion as it might have first appeared to be. The oldest trick in the book is to change a product’s name or designation to justify a price increase, to explain away enforced change, or to rekindle press and consumer interest -- occasionally based on the flimsiest actual improvements. So it’s entirely appropriate to ask what has been revised to make the latest version of the Reference 6 special and warrant anointing it with that SE suffix. A glance suggests that little has changed. The evolution involves no changes to the circuitry or tube complement (six 6H30P tubes in the line stage, and one 6550WE and 6H30P in the power supply), and the specifications remain identical. The front, side and rear panels are virtually identical. The back panel has a metallic decal with the letters "SE" added after the screen-printed “Reference 6” but otherwise remains the same. The only physical change to the chassis is the substitution of a much thicker, but still acrylic, top plate.

The changes Audio Research did make will transport those of a certain age back to the 1980s, when the often all-consuming passion of impoverished audiophiles was to take a well-received but modestly priced component and systematically upgrade the wiring, capacitors and resistors. Dynaco and PS Audio products were fair game, and even without the aid (or existence) of the Internet, there was plenty of information in the non-mainstream audio press about swapping parts. For those, like me, living in the San Francisco Bay Area, regular trips to electronics-parts stores in Silicon Valley would be combined with raiding sorties on South Bay record stores.

The Reference 6 SE differs from the Reference 6 in that 18 capacitors have been upgraded with proprietary components made especially for Audio Research. In addition, 14 runs of wiring have been upgraded, as well as that acrylic top plate. The retail price has risen from $14,000 to $17,000, but owners of the original Reference 6 can have their existing preamplifiers upgraded to current SE status for that $3000 difference.

If you are ever tempted to experiment with your Audio Research or other gear by switching out parts, proceed with caution. As with automobiles, the insides of electronic components have grown far more complex over the years, not to mention that the cost factor makes a mistake much more expensive than frying an old Dynaco amp. That’s not to say it’s not done. I still have friends whose electronic skills have remained sharper than mine and who swap out capacitors hoping for improved sound. Such is the enthusiasm for the Audio Research brand that audiophiles on a budget have been known to pick up an early-model Reference product and swap out its components for those used in a later generation. They consistently report significant improvements as a result of changing capacitors and resistors, although I suspect that human nature might also play its part: People are prone to liking whatever they've had a hand in making.

But let’s not confuse the impact of a ten- or twenty-year evolution in component quality with the company’s upgrade of its own Reference 6. What Audio Research has done with the Reference 6 SE is a horse of a different color. With an old Dynaco kit, you knew you were starting with the cheapest resistors, capacitors and wiring, components that set the bar pretty low. Upgrading to better-quality components was likely to result in a different- and probably better-sounding product. But in this case, Audio Research didn’t decide to swap out cheap parts for high-quality alternatives. They were trying to determine if they could find a new or different high-quality part that might sound better than the high-quality part they were already using. Working from a variety of prototypes, they have developed a proprietary capacitor, with a unique combination of construction and materials, that best suits the characteristics of their circuit design. Final design decisions were made based on exhaustive listening tests. It’s an approach first applied during development of the Reference 160 amplifiers, finding, in ARC's words, an improvement in “overall aliveness -- never before experienced in Audio Research tube amplification” and due in large part to the incorporation of superior capacitors and wire.

Rather than relying on memory, I directly compared the Reference 6 to its replacement. I’ll admit that my expectations were well in check. When I compared the Reference 6 to its predecessor, the Reference 5 SE, I noted “a significant increase in bass energy and dynamic speed and intensity,” and throughout the rest of the frequency spectrum it allowed the system to “breath deeper, allowing a lighter touch and greater level of nuance.” How much difference could there be where the circuit configuration remains constant, the only changes being the substitution of parts? Yet Audio Research’s Dave Gordon and Warren Gehl bullishly assured me that I should expect significant sonic improvement.

he first place I visited was the audio basement. My doorway downstairs is Trance Planet, a long-out-of-print compilation CD [Triloka 7210-2] that includes the cut "Angelica In Delirium" by G.O.L. (Gods of Luxury), a group that recorded two albums, one with lyrics from the Song of Solomon and the other from the text of Huxley’s Brave New World. It is the only “space music” album that has remained in my collection, years after the genre’s heyday. First, it is just great dance/trance music, rather than the usual insipid stuff that sunk the style. Second, it has some of the best-recorded bass I’ve ever heard. It revealed the 6 SE’s tighter, more articulate bottom end -- as all good dance music should. At one point, G.O.L. overlaps a series of gigantic-sounding synthesized bells. With the Reference 6 SE, each succeeding bell existed in a layer of space, each bell’s reverberation distinct from the others. The Reference 6, by comparison, slightly blurred each bell’s placement, producing a warmer, more rounded effect. Similarly, the Moog bass lines of "Autobahn" from Kraftwerk’s album of the same title [Klingklang 50999 3 08300 2 8] immediately showed off the improved clarity and intelligibility of the Reference 6 SE. The new preamplifier’s bass definition dispensed with its predecessor’s overhang and tendency to warm things up with a touch of tube sound. Instead, the Reference 6 SE delivered improved dynamic punch and low-frequency shape without any hardness or glare.

With small-scale musical groups and non-synthesized instruments, the 6 SE’s refinements were every bit as significant, if not as immediately apparent. They played especially well with small-scale jazz. Lee Morgan’s Candy [Blue Note/Music Matters MMBLP-1590] is among my favorite Music Matters Blue Note reissues, an LP I play so often I regret not picking up a couple of extra copies before it went out of print. Unlike most Music Matters reissues, Candy was remastered in all its mono glory. But it is mono that might be mistaken for stereo, with the four musicians each occupying an identifiable space, rather than clumped together on top of each other. Like the taming of the synth bell reverberations of "Angelica In Delirium," the separation of those four instruments on Candy was more readily apparent, each image more solid, resulting in a more three-dimensional sense of each player, with a clearer and more open space between them. This in turn resulted in each instrument being more dynamic, each note no longer weighed down or blanketed with spurious reverberation. This was most obvious with Art Taylor’s drum kit, as the snap, crackle and pop of his sticks celebrate their freedom from unwelcome energy.

You’ll find a similar improvement on the fabulous Impex Records One-Step remastering of Patricia Barber’s Café Blue [Premonition/Impex Records IMP 6035-1]. With the Reference 6, one could be excused for wondering just how the sound of this recording might be further improved. The Impex version has already significantly upped the ante when compared to the many previous audiophile reissues, ticking all the sonic boxes, from resolution and speed to dynamics and heft. But the Reference 6 SE showed that even apparent perfection could be improved upon. "Mourning Grace," the second track, is not standard female-vocalist fare -- a Maya Angelou poem recited over a haunting, repeating piano phrase, then joined by electric guitar and finally spotlighting the drum kit. The One-Step's improved dynamic scaling was immediately obvious with the 6 SE, each instrument demonstrating an explosive dynamic capability, from a whisper to a blast. When the drum kit takes over, the improvement in the speed and clarity of the cymbal and snare transients was breathtaking. As good as the One-Step record sounds with the Reference 6, the Reference 6 SE married the warmth and presence of tube sound with the clarity and attack of solid state, to an extent I’ve only previously experienced with some of the CH Precision electronics.

This improvement in articulation was not limited to drums and electric guitar but ran the entire instrumental gamut. Just listen to György Ligeti's "Balada si joc," (Ballad for two violins) on Patricia Kopatchinskaja’s newest CD Plaisirs Illuminés [Alpha 580]. Kopatchinskaya and Suyeon Kang trade licks in a short three-minute piece, and if this doesn’t convince you what a difference a mere 32 capacitor and wire changes can make, nothing will. The updated preamplifier separated the two instrumental lines with far greater clarity and ease. Where the Reference 6 pushed the two players together and edged them toward the right side of the stage, so that at times it was a bit of a strain to figure out which of the two was playing what, the Reference 6 SE separated the two far more convincingly, moving them closer to center stage, eliminating the slight blending introduced by the Reference 6.

I’ve seen Kopatchinskaya (the Lady Gaga of classical violin -- at least when it comes to her costumes) perform several times, and among my COVID cancellations was one of her concerts. Her characterful persona isn’t just for show, but informs every aspect of her playing. She is often referred to as the “barefoot violinist,” entering the stage in one of her eccentric outfits, she’ll step out of her shoes, the better to plant her feet, bringing added verve, vigor and presence to her vivacious playing. Switching from the Reference 6 to the 6 SE changed a decently recorded ballad for two violins into a remarkably stable and three-dimensional aural photograph, one so vivid that it almost allowed me to picture her costume. This was not just the result of improvements in the time domain that sort out the spatial clues. The clarity and resolution at the top-end seemed to excel when it came to reproducing the attack and harmonic shape of the violins’ high notes. The same effect was obvious with piano recordings. Daniil Trifonov’s piano solos in Stravinsky’s "3 Movements from Petrushka" [Deutsche Grammophon Gesellschaft 483 5331] revealed a piano sound where the right-hand work was more naturally dynamic and devoid of smearing than before, without ever teetering into digital sterility.

From a modern performance recorded in a thoroughly modern style, I moved back in time a few decades and tossed in a full orchestra with Arturo Benedetti Michelangeli’s incomparable live 1979 performance of Beethoven’s Piano Concerto No.1 with Giulini conducting the Vienna Symphony at Vienna’s Musikverein [Deutsche Grammophon Gesellschaft 449 757-2]. The disc in question was a plain-Jane, no-frills DGG “The Originals” CD reissue with no audiophile pretensions, yet it demonstrates just how much hall sound can be captured on a Red Book CD if the engineers are proficient and get it right. Conversely, it demonstrates how much your CD player or preamplifier stands between you and the fragile information captured in those polycarbonate pits.

The Reference 6 did an admirable job of reproducing the sound of one of the world’s great halls. But this is a disc that reveals the entirety of the musical benefits of the Reference 6 SE, the walls expanding and the hall boundaries becoming distinct, the dynamic range growing wider and more pronounced at the macro end, the overall resolution an absolute to my ears. I have heard this music reproduced to even greater effect, with a system featuring the Wadax Atlantis Reference DAC and Robert Koda K15 line stage at the 2019 High End show coming to mind; but that’s topping a couple hundred thousand dollars for just those two components. For a tenth of the cost, the combination of Reference 6 SE and Neodio Origine CD player came affordably close to the otherworldly sound produced by seriously, and seriously expensive, state-of-the-art products.

or owners of an Audio Research Reference 6, the $3000 upgrade path is a no-brainer. I can’t see how spending three grand anywhere else in your system is going to reduce the difference between your listening seat and club or concert hall seat by anywhere near as much as this upgrade. The words of praise I lavished on the Reference 6’s improvement over the Reference 5 SE echo in my mind. This most recent upgrade has impressed me even more than that prior step up in performance. And if you're buying anew, the resolving power and dynamic prowess of the Reference 6 SE will be hard to equal at any price.

Despite the challenges present in a change of ownership and a global pandemic, Audio Research has not missed a beat. Even given the looming shadow of ARC’s storied history and reputation -- and the inevitable expectation that accompany them -- the Reference 6 SE doesn’t disappoint. Stellar preamplifiers are few and far between. This is one of them, and the price of the upgrade makes it an especially impressive achievement.