Audio Research Reference 6SE line preamplifier

"As long as you're happy."

That's the line long uttered by the most dreaded members of my family, and their friends, whenever they tried to pry into my personal affairs. Often the last word, "happy," was uttered with a downward cadence and accompanied by a shrug.

Then came the kicker. "You are happy, aren't you?" said with eyes boring into my soul. "Well, as long as you're happy."

Cue the telltale shrug. With disapproval voiced and points scored, it was time for the obligatory peck on the cheek, handshake, or—worse—mutual male hug disguised as burp assistance.

Thus were the seeds of doubt planted by those who used words and looks in place of cordless leashes and electroshock. Was I truly happy, or was I masking deep-rooted existential disease? What does it mean to be happy? Is contentment good enough, or is it merely a convenient compromise?

Irony of ironies, here I am decades later asking myself the same question. Except, whereas before the mandate to probe my emotions was intrusive and unwelcome, now it's something I'm paid to do as I listen to audio equipment and recordings. Just what are you really feeling while you're listening, Serinus? You are happy, aren't you?

Questions asked become questions owned. Karma and dharma united in a macabre dance, à la Shostakovich.

Which brings us, in ways that will hopefully become apparent, to the latest piece of gear to fall within the Serinus reviewing sights, Audio Research Corporation's new, top-of-the-line single-chassis line-stage preamplifier (footnote 1), the Reference 6SE ($17,000), ARC REF 6SE for short. An updated version of the discontinued REF 6 ($15,000), which was released in 2015, its changes include new capacitors and a lot of new wiring. Otherwise, the preamp's fundamental design, housing, and specs remain the same. Current REF 6 owners can upgrade to the 6SE for $3000. All new parts are installed by hand in a changeover that requires a full day.

According to Audio Research Corporation's extremely knowledgeable and articulate national sales manager and brand ambassador, David (Dave) Gordon, who has been with the company for more than 31 years, the REF 6SE was made possible by the many years of development and research that produced Stereophile's 2018 Joint Amplification Product of the Year, the 160M monoblock amplifier, reviewed by yours truly, and the 160S stereo amplifier, reviewed by Jim Austin. The engineers who worked on those amplifiers were responsible for the development of the REF 6 and the REF 6SE.

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"In the final stages of developing the REF 6, we spent a year working on capacitors, especially coupling caps, because they made such a big difference," Gordon explained by phone. "We listen to the distinctive sound of all the caps we get, and change wraps and materials (eg, foil, quality and amount of copper, dielectrics, soldering) as necessary because they always make a difference. It's like making a fine dish. A good cook will sample along the way and add a little more spice or salt to taste. That's what we do with our circuits. We know what our products sound like, and we're looking to get better sound without trade-offs."

Eager to apply what they'd learned in developing the 160S, ARC's engineers first tried changing some of the REF 6 preamp's capacitors. Then they focused on hook-up wiring, incorporating wire from two different manufacturers and experimenting with different dielectrics. Finally, they put the two together and tweaked until everything worked synergistically and the company's "ears," Sonic Evaluation/Materials Engineer Warren Gehl, signed off.

"We know that we can hear things we can't measure," Gordon told me. "Bill Johnson, who founded Audio Research in 1970, always made a point of saying that we measure statically but listen dynamically. When we measure, we cut off the signal in time; when we listen dynamically, the music flows. We just don't have enough measurements to describe what we're hearing. Something can measure well and sound bad. Skilled engineers learn how to tweak the circuit and parts to produce the sound they want. That's where the art lies."

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What it is
The REF 6SE is a fully balanced, class-A design with zero feedback. To quote the late and great Art Dudley, who authored the REF 6 preamp entry in the fall 2019 edition of Stereophile's Recommended Components, "The audio circuits include three 6H30 dual-triode tubes per channel, while the power supply has one 6H30 and one 6550WE tube. The eight pairs of line-level inputs are evenly divided between single-ended (RCA) and balanced (XLR), alongside three pairs each of single-ended and balanced outputs. Among the Reference 6's electronically controlled functions are its 103-step volume control, signal-polarity inversion, and a mono switch. [Michael Fremer] noted the Reference 6's unimpeachable specs and reported that while listening to favorite recordings through it, he heard 'intense surprises that I'm sure can't be measured. Record after record, I found that the Reference 6 greatly increased my understanding of very familiar recordings.' In measuring the Reference 6, JA noted 'superb channel matching, 'inconsequential AC-supply noise,' and, overall, 'little hint of the presence of tubes in the circuit'—that last observation intended as a compliment."

When, at Gordon's suggestion, I used the REF 6 preamp in my review of the 160M monoblocks, I found that it enhanced air and depth as well as midrange beauty. Once I replaced my DAC's volume control with the REF 6, "the sound of the horns was to die for, and bass lines were well defined," I wrote. "Everything sounded more substantial and gained in emotional impact. ... The bloom [my friend Gary and I] heard with the ARC pairing of Reference 160Ms and REF 6 sounded heavenly to our ears. Forget the oft-invoked 'It's all good'—what we heard was much better than that." The REF 6's relatively modest touches of warmth and roundness, which were quite pleasing, left me eager to discover how its REF 6SE successor would sound.

Easy Easy
Even without grasping its front handles, it was a cinch to hoist the 37.5lb REF 6SE preamp onto the top shelf of my four-shelf Grand Prix Audio Monza rack. To connect the 6SE to the D'Agostino Momentum monoblocks, I chose whichever of the REF 6SE's balanced outputs best allowed me to avoid crossing or touching other power cables. (The REF 6SE, like its predecessor, requires a 20-amp power cable, whose component-end termination differs from that on a 15-amp power cable. There's one in the box of course, but I maintained sonic consistency by using a 20-amp version of the Nordost Odin 2 power cables I use elsewhere in my system.) When cables did cross, I used extremely rare, imported-at-great-risk Portuguese Styrofoam blocks, available in lurid, quasi-dayglo green and laidback charcoal colors, to separate the cables. Despite the markedly different emotional responses those colors elicit, I found that as long as I didn't shine a spotlight on the green ones, their colors did not affect sound quality (footnote 2). What did affect sound quality was the choice of supports between the REF 6SE and the rack's bamboo shelves. More on that follows.

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Throughout the review, I stuck with the dCS Rossini DAC/Rossini Clock combo fed by the Roon Nucleus+ music server with outboard HDPlex linear power supply. While I could have also used the EMM Labs DV2 Integrated DAC, I figured that the extreme openness, transparency, and resolution of the dCS combo, as well as its extended, lively top, would be most conducive to discerning differences between the 6SE, my aural memory of its predecessor, and other preamps I might invoke for comparison.

Given the 6SE's balanced design, I also used balanced interconnects between the Rossini DAC and the REF 6SE. When I briefly tried the 6SE's single-ended inputs, I was not convinced that they transmitted equally transparent sound.

Not so easy
All that sounds simple, doesn't it? Alas, as alluded to in the intro, the simple and direct path to happiness is not the Serinus way. Thus did Yours Truly complicate matters by asking Editor-in-Chief Jim Austin and Technical Editor John Atkinson to send the loaner Benchmark LA4 ($2599) and MBL Noble Line N11 ($14,600) preamplifiers they had on hand so that I could compare them, as well as my reference D'Agostino Momentum HD preamp ($40,000), with the ARC REF 6SE. The three other preamps use 15A cords. The D'Agostino offers only balanced inputs and outputs. Because I only had room for three preamps on my eight-shelf rack, the Benchmark warmed up on the floor until I finished listening to the MBL. I used the Rossini's 2V output throughout the review.

Do not begin to think what it was like to keep 12 power cables and an obscene number of interconnects and grounding wires separate, let alone match volume as I moved between four preamps and the Rossini's own volume control. Happy to say, I didn't once put the integrity of the tweeters of my Wilson Audio Alexia 2 loudspeakers (or my ears) at risk by forgetting to turn the Rossini's volume down from its maximum 0dB setting whenever I switched from one of those four preamps' volume controls back to the Rossini's.

Gordon suggested I give the already–broken-in REF 6SE two days to settle in before beginning serious listening. The unexpected treble edge I heard when I snuck in an immediate "I can't resist" listen confirmed the wisdom of his counsel.

Now you hear it, now you don't
Two nights later, I began my first serious audition. "Am I really getting paid to do this?" I wrote in my notes as my speakers poured forth some of the most polished, transparent, and arresting sound I'd heard from my system. The absurdity of calling such pleasure-inducing happiness "work" left me smiling.


Footnote 1: Audio Research also offers a 2-chassis preamp as part of its Reference series, the Reference 10.

Footnote 2: Am I being serious? Well, even though my surname is Serinus...

COMPANY INFO
Audio Research Corp
6655 Wedgwood Rd. N, Suite 115
Maple Grove, MN 55311
(763) 577-9700
ARTICLE CONTENTS

COMMENTS
CG's picture

This beggars the obvious question - Which provides the magic? The setup or the gear?

Certainly it's a combination, but is setup undervalued? It reads to me like the system setup for Jason was roughly as significant in defining the sound quality and appeal as the new preamp. Perhaps I'm reading a lot into this, but what's going on? Is this like cooking, where the preparation and the seasoning often matters as much or more than the raw foodstuffs?

I've often marveled at how enthusiasts are willing to buy preamp after preamp, as one example, but will not even consider adding modest acoustic treatment of their listening quarters. Is that really sensible?

One famous owner of an equally famous cable company spoke many years ago in Stereophile how the selling prices of his products were based on the magnitude of sound improvement brought by using those cables over others. The actual cost of the product for him and the rest in the supply chain was irrelevant. If a certain cable made as much improvement as jumping to a three times as expensive amplifier, shouldn't the pricing for that cable be the same as for the amplifier? Whether you agree with that pricing philosophy or not, and it certainly has fanned some of the flames associated with the cable argument, there must be some basis in the results since people continue to buy more expensive cables. Herd mentality?

I'm not offering an opinion here. Merely asking.

Allen Fant's picture

Bravo! JVS
I really enjoyed the introduction leading into this gear review.
A Reference System + Equally Good Music = Happiness! Simple.

latinaudio's picture

... your article dismantles all comments directed to overvalue the relative low cost and high quality of the Benchmark LA4. It's a good device, but it's "light years" behind the best despite its flawless specs.
I'm tired of reading from objectivists that Benchmark products are "supreme" just because JA achieves excellent results when measuring them.
Audio Research, Dagostino, Ayre, DCS, etc. are out of my reach, but from what you and other reviewers have expressed they undoubtedly sound "in another league". So no: the Benchmark products are not what its fans say they are: cheaper yes, but better never...

Kursun's picture

Yes, the more money you pay sweeter it gets, for some!
As a matter of fact, overpricing is a well known marketing strategy as a bait for those people.

latinaudio's picture

If it sounds better it's simply better, what else is it about when we evaluate equipment? If it´s more expensive isn´t necessarily better (PMC fact.8 signature comes to mind).
Until the day you know what to measure exactly (and how to do it!)you will have to trust your ears absolutely. Like the ones from the stereophile reviewers, which is why I assume everyone reads this magazine, or not?

Glotz's picture

... Does not dismantle the other reviews that this and other magazines provided.

You rush to negative conclusion in the same way others rush to praise it.

What about the amp's input and output impedance mismatches with the LA4? JA specifically addresses the good match for the ARC Ref 6SE with the D'agostino, but does that imply it's also a good match for the LA4. Dubious.

While I do agree the objectivists are largely full of it, and on this site they have too overhyped various components in the line, but does it mean that JVS was 'correct' in his dismissal of the preamp to the others?

What about the additive nature of the Ref 6SE? The treble and bass in particular have been addressed over time and tailored. Is that less accurate as a result? Yeah, probably. Does it matter to great sound? No. It sure don't!

I have heard this preamp for about an hour with 160M's with equal gear in a well-set up dealer's system, with great a great LP playback in tow.
I love it!

But that doesn't necessarily mean that the LA4 is worse or less accurate, just different, and different in JVS' system. He, rather, decided to make over-arching claims that the king has no clothes and referencing JGH and others.

I prefer if on the other more 'subjectivist' end of the spectrum we would ease up on the pronouncements that so well polarize audiophiles, or at least refrain from pure 'finality', when the job is to report on what one hears...

tonykaz's picture

It's a nonsense question, isn't it?

A person must discover the totally unique creature that they are.

It can take decades to purge cultural norm guidance.

Once someone stops being the person someone else demanded, life begins it's wonderful and exciting journey.

No-one is a Black Sheep, the people saying Black Sheep are the problem.

Be the unique person you are and celebrate life, everyone will stand with you. ( even if you're a trouble-maker like me )

I've always been pulling for you.

Two thumbs up

Tony in Venice

doug beechwood's picture

So the unexplored question here is... why is there a 20A IEC power connector on a preamp that draws 130 watts? And what connector is on the other end of the supplied power cord; a 15A or a 20A?

The specs shows the unit suitable for operation at 240VAC. Does this mean it has a switching power supply?

I'm awaiting delivery on 290 lbs. of an air conditioner & furnace. Installed by others, with a city building permit, and a 3rd party HERS test. Painfully expensive, but still $7000 cheaper than this item.

stereosnarf's picture

I've owned several pieces of ARC gear and they are great, but...

It really is all about the sum total of all the components and it's tough to know in advance what plays nicely with what. A mismatch of just one component can leave you feeling cheated.

An example; I own a Parasound JC5. I also auditioned the A21+. They are great amps... until you hook them up to a Magnapan speaker. That pairing is awful. The bass shrinks dramatically and the highs bloom a bit too much. Switch over to some cone-driver speakers (Ryans) and suddenly all is well. The difference is stunning. I can drive the Maggies with ARC or Manley gear and the Maggies and Ryans sound much more similar.(and great)

In that light, it's even easier to understand why manufacturers want you to use their components throughout your system. Theoretically, all mismatch has been eliminated.

tonykaz's picture

ARC was the most desirable Audiophile Brand.

I owned a few pieces and thought it was over rated but it had a nice industrial feel for owners.

Conrad Johnson, that I represented, was also over rated ( in my opinion ).

Today I wouldn't own either brand at eBay prices, much less new prices. ( I will buy at Yard Sale prices for resale ).

A person gets Bragging rights with ARC and pricy replacement tubes.

Still, ARC stands by all their stuff, no matter how old. Gotta love 'em for that.

and

I miss my local ARC Dealer, Harry Francis of Audio Dimensions in Birmingham, Mi. Hello Harry if you are reading this, I wish you were here in Venice-- I'll buy you a nice Sea Food Dinner at Sharky's when you're in town !

Tony in Venice

JHL's picture

...tinged toward negative personal anecdote from the past that dings the integrity of manufacturers or the choices of listeners isn't as pertinent as commentary on the real sound and owner feel of contemporary equipment.

It's free press. Commenters should remember the topic and show some appreciation for the effort to produce it.

tonykaz's picture

Accurate phrasing for sure.

I buy and sell this type of gear on the regular. ( eBay and elsewhere ).

My opinions are based on personal experience ( decades of personal experience ).

My 'Value for Money' equation is the main ingredient colouring my opinions that I'm able to share, they are just as valid as your opinion of my writings.

I share my Price Tranche philosophy with Steve Gutenburg's comfort level in pricing.

Super pricy gear deserves plenty of extra scrutiny and disapproval when justified.

ARC's integrity is outstanding, their dealers are typically outstanding.

Owner Feel is real for ARC, I agree.

ARC's Value for Money is supported by the outfits continuing Service ( for a hefty price ).

ARC has a kind of Aston Martin luxury positioning in the Marketplace.

I'm always happy to buy another ARC piece, I've just never had one that stood out as a keeper and I'm a little suspicious of reviews touting an ARC piece in the Concluding comments. ( which I suspect the reviewer MUST write )

Tony in Venice

ps. if you own an ARC piece, share your performance evaluation experience.

ps 2). the high MSRP Retail Price of this piece is what drives support for the higher used prices of ARC gear.

JHL's picture

...how to string that all together to reflect or expand on the article but you're right that opinions happen. Some hew closer to pertinent reality than others too, which if we're on about sound and hardware, helps.

tonykaz's picture

I've never owned any piece of Audio Gear that performed as well as a Magazine Reviewer reported. I attribute it to Manufacturers carefully selecting pieces to send to magazines. Typically, any two ARC SP 6b's will sound different. Certainly, the Conrad-Johnson Premere 1 Amps, I sold, did not sound like the reporting that Tony Cordisman did on the original review sample ( a rave review ), the new ones I sold ( as a full line dealer ) were not wonderful in any way. ( the MV-45a was the Pavaratti of the Conrad-Johnson range ).

Tony in Venice

JHL's picture

...that about the only way I can, which is as an opinionated negative anecdote from the past with a side of projected manufacturer incompetence.

How it reflects on JVS and the 6SE is unknown.

tonykaz's picture

Jason just wrote his best piece yet, he's a unique person with something to say.

ARC is ( as far as I can tell ) a wheezing Dinosaur, attempting to recapture the illusive Bill Z's tremendous success.

Magnapan, on the other hand, remains the Outstanding Audiophile Contributor from the frozen north of Minnesota.

My opinions, only!

Tony in Venice

JHL's picture

...are a lot of great engineers and a lot of entirely competent manufacturers.

Given that neither original company or chief engineer remain, and given that you're projecting intent against type, how does criticism follow?

tonykaz's picture

Audio Gear priced at Automobile price levels leaves the gate wide open for generous criticism.

The gear should sound outstanding but it typically doesn't ( my experience ).

You can critique me for being critical, if you like.

Being an Audiophile is all about discrimination and critical evaluations.

Plus, there is plenty of room for differences of opinion.

I like ARC for it's ability to attract buyers not for it's sonic performance.

so, I buy ARC at the right price and sell.

Tony in Venice

JHL's picture

...more followup about ARC or its engineers or purported values then. An improvement over imagining them.

I imagine a world in which comments threads trailing free editorial content apply to better sound and camaraderie, not asserting a corporate ethic or quizzing the guy taking the gear home or the socio-economic failings of whomever. John Lennonists will appreciate that stereophile's utopia.

tonykaz's picture

I imagine a world of wonderful music not based on pricy.

All of us are peaceable comrades with unique and valid opinions.

We have a passion for our little niche hobby, mine has been lifelong.

I also have a certain love for Stereophile and JA1 since his HFN&RR days, I don't subscribe or read the other Audiophile Glossys. Stereophile's Editorial Content Percentage is the largest of any Journal I'm aware of. ( I do follow the Audiophiliac on YouTube, of course, and miss Mr.Dudley & Tyll )

Stereophile attracts the intellectual vein of Readership and commenters with it's outstanding Editorial Guidance and mostly verbose & poetic reviewers.

Stereophile is "Home Sweet Home" for Audiophiles Globally.

Tony in Venice

MatthewT's picture

Ever get boring and repetative to write? It does reading it.

"I'm always happy to buy another ARC piece, I've just never had one that stood out as a keeper and I'm a little suspicious of reviews touting an ARC piece in the Concluding comments. ( which I suspect the reviewer MUST write )"

teched58's picture

Seeing your (tonykaz) sig, all this time I thought you were in Venice Venice (i.e., Italy). Who'd have thunk it's actually Florida!

tonykaz's picture

Florida is Quality of Life!

Venice Italy is history !

Venice Florida is an incubator for old people, swimming in the pool, year round sun shine, rainbows weaving thru shades of gray rain clouds, fresh seafood at the Amish Market and very little culture.

Italy is thick with the Cultural Civilization of my ancestors.

I have a Colnago Master lite steel bicycle hanging in my office, it's as close as I'll probably get to living in Italy. ( from the Eddy Merckx era )

Tony in Venice

FredisDead's picture

JVS is no doubt a very nice guy. But IMHO his talents lie in show coverage. His reviews are often too much a personal pursuit and a reflection of himself rather than the subject of his review. It as though where you, me, and all of us would look at the subject of this review and see an ARC Ref 6SE, he is looking at a mirror. The new editor made a mistake. This review should have been assigned to Mike so that the rest of us could read something meaningful, particularly if we want to know the qualitative difference between the Ref 6 and Ref 6SE.
This review is absolutely worthless. In fact, it is outright painful to read.

tonykaz's picture

I've been overly harsh too.

I need to soften up.

I'm blaming my anger on what the donkeys did to my Bernie.

Oh well, moving on.

Sorry isn't strong enough.

Tony in Venice

gtaphile's picture

I wish the review samples of these hybrids would include NOS replacement tubes as part of the kit. In my opinion having played with all aspects that one should play with (power conditioning, PC's, IC', equipment stand, footers, room treatments etc.) to optimize the preamp, the NOS changeover is the largest improvement. Clearly the opaqueness is lessoned as well image focus is improved.

ejlif's picture

I don't see the point of reviewing a preamp when you are digital only and running a DCS system known to be just as good if not better than running through any preamp at any price. If you have multiple sources and need switching then you are stuck with having to use a preamp but digital only, no preamp is a no brainer unless you just want to spend more money. The cables alone used are more than the cost of the preamp. 30K + for a marginal improvement and possibly worse sound is not much of a sales pitch.

Jason Victor Serinus's picture

that your statement is not true. dCS never claims its volume control is the end-all, be-all. If it did, it would not display with preamps from other companies at shows. Regardless, even if the dCS volume control were superior to every possible preamp design, it would still make a useful base point for comparison.

ejlif's picture

it is made clear by your review that a spending an additional 30K may get you nothing and if not worse sound maybe. It seems that most reviewers of DCS say ditch the preamp. I have a Rossini and clock but never had preamp with it. I'd like to add vinyl but just to much to try and find a preamp that will not actually degrade the sound of the Rossini. I think I'd go for an AD converter and phono pre before going to a regular analog preamp.

Jason Victor Serinus's picture

Glad to learn that you're asking based on personal experience. While the AR preamp definitely costs less than $30,00 - it's under $20,000 - the preamp I now use with my Rossini DAC/Clock combo is the D'Agostino Momentum HD preamp. It's more than $30,000 - $40,000 to be exact. Please see my review. I never cease to be amazed by this baby. It heightens color contrasts, but not in an exaggerated way; enlarges images in natural proportion; and is a monster when it comes to bass. It's also as smooth as can be. I had heard it with the Vivaldi stack at at least one store demo and perhaps a show before it came to me for review.

Ortofan's picture

... "heightens color contrasts", "enlarges images in natural proportion" and "is a monster when it comes to bass", is this device somehow extracting additional information from the input signal or is it creating these artifacts?

Is it simply a preamp - as in providing gain, volume adjustment and input switching functions - or is it additionally performing some sort of processing function to subjectively enhance the audio signals passing through it?

Jason Victor Serinus's picture

Your comment presupposes that there are absolute colors and image sizes on a recording, and that any preamp that, in contrast to other preamps, enlarges images, heightens contrasting colors, and transmits more bass information creates artifacts that are the results of "processing" and "enhancement." I would argue instead, based on what I hear, that the D'Agostino Momentum HD preamplifier moves reproduction one step closer to the real thing.

Take, for example, Seattle Symphony's recording of Richard Strauss' Also Sprach Zarathustra. I attended one of the two performances from which the live recording was assembled, and sat 8-10 rows back. There is no way that my Alexia 2s and the rest of my components, in my 16 x 20 x 9 room, can reproduce the sheer volume of the instruments that created the huge, glorious sounds I heard. My system can't move as much air, and if I turn the volume higher in an attempt to do so, I overload the room and potentially damage my hearing. The D'Agostino Momentum HD preamp moves me one step closer to what I heard compared to any other preamp I've ever used in my system, or what I hear when I rely on the dCS Rossini DAC's volume control. It takes me one step closer to the truth of my actual experience.

Having used the now departed from Serinusland dCS Vivaldi DAC in my system, I know that if I had it in my system instead of the Rossini, images and bass would be larger and weightier, colors would be even more saturated, and instrumental textures and the contrasts between them would be more palpable. Is the Vivaldi, in turn, adding information, bits, artifacts, or whatever you might wish to call them? Is it enhancing the signal? I would suggest instead that it enables me to hear more of what's on the recording. To my ears, the D'Agostino Momentum HD preamp does the same thing.

Ortofan's picture

... wasn't the Audio Research Reference 6SE the subject of the discussion?

Nevertheless, the question remains as to what aspects of the transfer function of a preamp (D'Agostino Momentum HD, or otherwise) might possibly account for its purported ability to allow a listener to subjectively "hear more of what's on the recording" than when it is not in the system?

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