The Audio Research REF 6 Linestage

With a lineage stretching back to 1970 Audio Research, based in Minneapolis, Minnesota has built their reputation on constant, engineering based improvements to their products. Their Reference linestage preamplifier line remains a coveted commodity among ARC enthusiasts, and the Reference 6 linestage preamplifier solidly continues this tradition. Based heavily on what was learned creating the two chassis, Reference 10 flagship, makes for a major jump in performance over the outgoing REF 5/5SE, an award winning linestage in its own right.

More than a pretty face

On the outside, the REF 6 sports some eye-catching changes. ARC’s new chassis design was engineered for two reasons. First, ARC is updating the aesthetic of the Ref line. A clean, modern appearance moves away from the classic, more industrial ARC look. The visual design of the REF 6 comes straight from the desk of Livio Cucuzza and his team, the ones responsible for the trend setting aesthetic of the highly popular G-Series. Tastefully integrating style cues from the past models with a more modern look and better finish work, Audio Research components finally look as good as they sound.

ARC’s team also built in a greater level of structural rigidity intended to “assist in the dissipation of electrical and mechanical interferences.” Immediately evident is the beautifully milled faceplate, available in either an anodized back finish or the natural aluminum finish of our review sample. Substantial handles on the front of the REF 6 pay homage to past models, offering a visual contrast to the otherwise flat front. The handles also offer a practical function when moving and placing the 36.5 lb. (16.6 kg) linestage. With overall dimensions of 19” (48 cm) W x 7.8” (19.8 cm) H x 16.5” (41.9 cm) D, the hefty REF 6 requires a fair amount of real estate on the audio rack.

When placing it, headroom is another important consideration. The tube complement generates a lot of heat and adequate ventilation is necessary for the long-term health of the unit. Under the REF 6’s transparent, vented Lucite hood, the owner can witness the tidy circuitry within. The tube complement consists of six 6H30P dual triodes, plus a single 6550C and a 6H30 regulating the beefy power supply.

Control freak

As part of the newly-adopted aesthetic, an elegant simplicity drives layout of the REF 6 control panel. In addition to the large input selection and volume knobs, six dime-sized buttons manage the rest of the adjustments. Specific buttons control power-up, a choice between mono or stereo playback, phase reversal, and mute. The remaining two buttons, “menu” and “enter” bring to life the REF 6 menu options, and allow the owner to customize his or her preferences for each.

To get the most from the REF 6 tube complement, one menu option allows the user to see the number of hours on the current tubes. According to AR, new 6550WE tubes should serve their owner for about 2,000 hours, and the 6H30 tubes offer roughly twice that life span. When the tubes eventually wear out, ARC offers carefully matched replacement tubes. As there are not a lot of variations on the 6H30 tube, just giving the factory a call is the easiest way to roll. To maximize tube life, owners will delight in another REF 6 feature. The owner can set an automatic preamp shutdown to engage at a one to eight-hour interval. This feature can be disabled if you prefer fully manual control.

The REF 6 also offers the ability to assign a specific input for home theater pass-through in instances where the linestage is part of a larger home theater system. In this scenario, the REF 6’s volume control disengages when that particular source is selected, deferring to the surround sound processor’s volume controls. The ability to assign names to each of the REF 6 inputs also makes it easy to keep inputs straight on more complex systems.

ARC has always offered a very basic, plastic remote. Keeping with the aesthetic of the new design a milled aluminum remote accompanies the REF 6 and REF Phono 3. It’s a nice, but not ostentatious touch that complements the new look, and is roughly the size of the plastic remote of old. Prospective owners should note that the REF 6 sports a 20-amp IEC power socket, so if you are contemplating a power cord upgrade, plan accordingly or find a high quality adaptor, like the one from Shunyata.

Featuring four inputs, each having the option of single ended RCA or balanced XLR connectors makes the REF 6 one of the most versatile linestages going. Two sets of RCA and XLR variable outputs are joined by a fixed level, record out option – handy for those either stepping up to the tape game or digitizing some of their favorite music. 12 volt trigger and RS-232 interfaces are also available for those wanting to tie everything together, or in a custom install situation.

Music to my ears

When the power button is depressed, the REF 6 kicks into a 45-second warm-up mode, bringing the tubes up to temperature slowly, maximizing their lifespan. Mute is engaged automatically during that process, and must be un-muted before music can proceed.

Right out the gate, the REF 6 proves stunning in several ways. The immediately enveloping soundstage has musical elements bursting in all directions, projecting a seemingly limitless picture that defies speaker placement. Airy subtleties reside in the distance above, below, and behind the speakers offering a spooky level of realism, and the REF 6 is one of a very short list of special linestages that renders an incredibly real picture of the recording without crossing the line of being super sized for effect. Listening to Lucinda Williams “Can’t Let Go” places her in my listening room at a correct size, making the presentation that much more believable.

Combined, these characteristics give not only insight into the subtleties engineered into a song, but a sense of the space used to record it. At the same time, the musical picture never seems artificially inflated. Similarly, the organ notes in Johnny Cash’s treatment of “Danny Boy” found on American IV: The Man Comes Around, paint a palpable picture of the cathedral used as the recording location. Cash’s gravelly immediacy, combined with the subtle reverberation in the recording hall has me looking over my shoulder, feeling if I’ve seen a ghost.

In my reference system, the REF 6 provides a very slight degree of warmth to the musical picture alongside its ability to retrieve tiny sonic details from a recording. In my experience enjoying equipment over the years, that balance can be a tenuous one for a product designer to achieve. A convincingly realistic and detailed presentation is desirable, but that sonic goal can sometimes lean toward an overly-lush sound, or be accompanied by etch or stridency. The REF 6 never hints toward either extreme which can detract from the organic sense of the musical presentation. The REF 6 provides a relaxed and natural musical flow emitting from the speakers. It’s easy to get lost in the sanctuary of beloved recordings and forget about everything else.

Bass reproduction represents another strong suit. On tracks like Jane’s Addiction’s “Three Days” all the pluck, resonance and rumble the sound engineer captured in the bass guitar track are projected with convincing authority. However, bass in never reproduced in an overly-accentuated, or one-note way. Again, the REF 6 reveals its innate character for organic reproduction. No apparent sonic manipulation colors the window into the music.

Regardless of musical genre, the REF 6 steps up to the challenge. Listening to classical, jazz, rock, electronica, reggae, vocal performances and anything else thrown at the REF 6, it never fails to impress. When speed and agility are demanded by the music, it delivers. Similarly, when delicacy and nuance are dictated by a recording, REF 6 nails that as well. Green Day’s American Idiot projects with all the angst and attitude one could hope from the album. In contrast, chamber music reveals the subtle differences between the various stringed instruments with ease.

Simply put, the REF 6 is among the finest linestages I’ve had the pleasure of hearing in my own listening space – it’s hard to imagine expecting or wanting more from a preamplifier. It would be easy to live with this linestage for the long haul. This caliber of musical prowess doesn’t come cheap, but at $14,000 it’s not crazy money either. Most importantly, the price has only increased $1,000 over that of the outgoing REF 5SE, so that’s major progress.

Additional Listening:  Jeff Dorgay

Being a Midwestern native, I’ve always appreciated the sheer practicality of the folks at Audio Research. Unlike my days of writing about digital cameras, sometimes a year before product is available, ARC rarely puts review gear in to the review stream until they’ve delivered the goods to their loyal customers. Bravo.

Needless to say, TONE staffer Tom Caselli was one of the first guys on the list and had his a few weeks before ours arrived, and he was quick to let us know the good news. “Amazing, way better than the REF 5SE that I traded in.” Other fellow audiophiles I know that are doggedly loyal to the brand echoed the same sentiment, at a higher level of enthusiasm than normal too, so the buzz was building around here.

Having owned the REF 5 and 5SE models and going way back with numerous ARC preamplifiers over the years, the REF 6 is a wider jump up the evolutionary chain than the past few models. As Rob mentions, it draws heavily on what was learned in the development cycle of the REF 10. At some point it may just be time for a head to head comparison…

While many have been asking for said comparison with the GSPre that has been residing here for some time, that’s not a fair fight, as the GSPre includes an excellent phono stage along with a headphone amplifier. Think of the GSPre as offering about 2.5 quarts of what a gallon of the REF 6 does with the other bits thrown in. The REF 6 will more than likely appeal to a different customer a few clicks higher on the audio food chain.

On top of all the sonic improvements, ARC has drastically diminished the time to great sound with their products. They still mention in the owners manual that the REF 6 will take 5-600 hours to sound its best, but unlike past designs, this one sounds fantastic out of the box. Granted, it does improve with time, but the delta is not quite as dramatic as in past models.

Whether you use the REF 6 as a reviewer’s tool or simply to relish your music collection, make no mistake: this is a destination component. There are a few others lurking that have a different sonic flavor, reveal a bit more music, or have a few more bells and whistles, but they will cost a lot more. In terms of sheer musicality, the REF 6 is the one to beat for $13,000.

Whatever they are up to in the lab at ARC is working. The REF 6 retains all the strengths of the outgoing REF 5 series, yet is more extended and dynamic, while adding more soul and musical saturation than the past model. That’s not an easy achievement, and I always wonder how they do it.

Keeping the price at $14,000 is impressive, especially in light of the major sonic and aesthetic improvements. The tough question is “should you trade up?” This depends on you. The REF 5 or 5 SE you currently own is certainly not rubbish by any sense of the word. They are currently fetching about $9,000 on the secondary market, so if you just have to have more juice, you won’t be disappointed. The REF 6 is not an update you have to strain to hear.

These are agonizing questions you ask when staring at the ceiling at 3a.m.. Who would have ever thought 30 years ago that audio engineers in 2016 would be pulling still more performance from triode tubes to increase our musical listening pleasure? That’s pretty cool. For those of you not suffering from trade up anxiety, run don’t walk to your ARC dealer and check it out. This linestage offers so much legacy, performance and long term value, we are happy to give it one of our Exceptional Value Awards for 2016. Life is short. Buy one.

The Audio Reseach REF 6

MSRP:  $14,000


Digital Sources: Mac Mini, Roon Music Service, dCS Debussy, Synology DiskStation

Amplification: Burmester 911 mk3

Preamplification: Coffman Labs G1-B

Speakers: GamuT RS3, JL Audio Dominion Subwoofers

Cables: Jena Labs

Power: Torus AVR 15 Plus, RSA Mongoose power cords

Accessories: ASC tube traps, Mapleshade Samson audio racks, Coffman Labs Equipment Footers, AudioQuest Jitterbug, Atomic Audio Labs Mac Mini stand

The Modwright SWL 9.0 Anniversary Preamp

Tracking through Radiohead’s newest album, A Moon Shaped Pool, the sonic landscape painted by ModWright’s entry preamplifier is impressive – even after I’ve just removed a big-bucks preamplifier from a system consisting of a CJ LP125sa+ power amplifier, the dCS Rossini DAC featured on our cover and my reference GamuT RS5i speakers, all cabled with Cardas Clear. Yep, this $2,900 preamp is getting the job done in good company.

Thanks to Tidal, running through 20 or 30 familiar favorite tracks requires much less time than when the original 9.0 arrived 13 years ago. Oddly, one of the things that impressed me most about the original ModWright preamp was Wright’s labeling the inputs both right-side up and upside down, making it easier to peek behind your equipment rack and facilitate connections. A small attention to detail, but one that convinced me that this guy had some insight.

A lot has transpired in 13 years. A quick drive up to Amboy, Washington proves fruitful, picking up one of the first SWL 9.0 Anniversary Edition preamplifiers from Dan Wright. The original SWL 9.0 (named for the 9.0 pound birth weight of his son Spencer) was Wright’s first product 13 years ago, after a four-year career of modding other people’s gear for higher performance.

That original preamplifier was well thought out revealing a lot of sound for the $1,999 asking price. At the time, tube moguls Conrad Johnson, Audio Research, BAT and McIntosh didn’t have anything in this price range, and the ModWright compared favorably with a few of their more expensive offerings. But Wright was a young manufacturer with only a few years under his belt and relatively low overhead. Yet now with a manufacturing facility, employees and considerably more inventory, he’s managed to not only grow, but also stay lean and keep prices in line.

Fast forward to now

Today, Wright has earned his stripes, proving himself in an industry that isn’t always easy to compete in, and over 400 units of the original SWL 9.0 were produced. When one occasionally pops up on the secondary market, it is usually snapped up rather quickly, proving that this initial product is still very desirable. Those still possessing the original, take note: the mother ship can still service these preamplifiers.

Like the BMW 3-series, Wright’s products are evolutionary, rather than changing direction every couple years. They just keep getting a little better, sonically and visually, with every iteration. In his office, Wright jokes about how much he’s learned about shipping as well. While the casework of the SWL 9.0 Anniversary Edition has been simplified somewhat to hit the price point, the machined aluminum top plate from the more expensive models has been tastefully replaced by a stamped piece of metal, and the faceplate is still thick, with equally robust control knobs, all machined with care. Carefully placed in an equipment rack, you’ll never know the difference and this is a great example of putting the money invested where it counts – in the sound quality. Also gone, much for the better, are the paddle switches of old, now replaced with gentle push buttons. I remember breaking one of the switches on my original 9.0, just as I did on my Audio Research and BAT preamplifiers of similar vintage, so this is a nice touch. The 9.0 SWL Anniversary feels like a far more expensive preamplifier, especially when you pick it up. This thing has to weigh about 25 or 30 pounds.

Nothing unessential

The SWL 9.0 Anniversary is a model of simplicity. Inputs on the left, volume on the right. Just like the original, it still “goes to 11,” so we can see that success hasn’t gone to Wright’s head and dissolved his sense of humor – though you’d never turn it up that far. About 12 o’clock was all any of my single-ended power amplifiers needed to achieve full output. Running a wide range of amplifiers, from a vintage, restored SAE 2200 amplifier all the way up to the Pass Xs300 monoblocks that are my current reference, compatibility is superb. It’s worth noting that this preamplifier easily drives a 20-foot pair of interconnects without sonic degradation, a plus for the audiophile in a more compact space who wants to segregate a power amplifier from the rest of the system.

Around back are four sets of RCA high level inputs and a pair of variable level outputs along with a fixed level output for those of you using a tape or digital recorder. I took the time to connect my VPI Classic 1/Lyra Kleos and Rega phonostage along with a Revox B77 to make a mix tape and can assure those who love to make their own recordings that the SWL 9.0 Anniversary Edition performs flawlessly in this capacity as well. While not ready yet, Wright has mentioned that in the future, the SWL 9.0 Anniversary will be available with a built-in, solid-state MM phono option for $300. And of course, you’ll be able to upgrade it if you purchased without initially.

The original circuit of the SWL 9.0 was a hybrid Mu stage and the current version still takes advantage of the 5687 tube, which Wright likes for its “linear and dynamic sound.” However, today’s SWL 9.0 Anniversary is a pure tube design with no solid-state devices in the signal path. Only the headphone amp relies on discrete MOSFETs in the output.

Initial listening was done as a drop-in with my main reference system, yet the smiles were equally huge in the context of a bit more reasonable system. Final listening was done with a Pass XA30.8 amplifier and the Simaudio 260D CD player/DAC, all cabled with Cardas Clear Reflection cable. Both the Rogers LS5/9s and the Quad 2812s were used as reference speakers.

Wright claims the headphone stage should be able to drive anything and mentions he used Mr. Speakers Ethers to voice this part of the circuit. It sailed through driving the Audeze LCD-2s and my Oppo PM-1s with ease. While not the last word in headphone amplification, this should more than do the job for the moderate headphone listener who doesn’t want to spend $400–$600 on an outboard headphone amp, the necessary interconnect and power cord. Personally, in the tradition of the best vintage preamplifiers, I really like having a good phonostage and headphone amp all on the same chassis. This will serve 90–95% of the users perfectly. And it makes this preamp even more of a killer value.

Keeps the pace

Extended listening keeps bringing one thing to the forefront with the SWL 9.0 Anniversary Edition; it has exceptional pace. Whether listening to something flawlessly mastered, or something dense and compressed like my favorite Monkees tracks, this preamplifier keeps the beat nailed down, never wavering. The bottom end is strong – neither overbearing nor thin – and the overall sound feels somewhere between natural and a few molecules on the warm side of the spectrum, but barely so. As it was thirteen years ago, the SWL 9.0 Anniversary Edition adds precious little sonic signature to the music presented and that’s a good thing.

It has enough depth and inner detail to convince you that this is not a solid-state preamplifier, but it is never overly warm, tubey, or euphonic. You won’t be confused that it might be a vintage tube preamp either.

Head-fi friendly

In addition to the sonic and aesthetic improvements, the biggest change to the SWL 9.0 Anniversary is the addition of a headphone amplifier. Considering that even a so-so headphone amplifier is going to set you back at least $400–$500, the cost of this preamplifier has really only gone up about $400 in over ten years. Not bad, considering how much Wright’s organization has grown.

Yes, we have a winner

Investing ten to twenty thousand dollars in anything, whether an automobile or a music system is still somewhat of a luxury in today’s world. Some of the most intriguing audio systems I’ve heard over the years have fallen in this price range, because if you want great sound at this price point, great care is required both in system setup and component choice. I can’t think of a better preamplifier to round out a system in this price point than the ModWright SWL 9.0 Anniversary Edition and am happy to award it one of our Exceptional Value Awards for 2016.

The five-figure preamplifiers still reveal more music, as they should. But the ModWright SWL 9.0 Anniversary Edition preamplifier nails all of the musical fundamentals, giving you a large enough portion of what the high end is all about. Unless you’ve got buckets of cash to spend, you can spend the rest of your life with this baby and not want for more. I’m certainly going to write Mr. Wright a check for one; half for old times’ sake and half to use as a reference in this neck of the woods. Here’s to thirteen more years. These days Spencer is tipping the scale at 100 pounds. Time flies indeed.

The ModWright SWL 9.0 Anniversary Edition Preamplifier

$2,900 (phonostage $300 additional)


Digital Source                        dCS Rossini DAC w/Rossini Clock and Paganini Transport

Amplifier                    Pass XA 30.8

Speakers                    Graham LS5/9 and Quad 2812

Cable                          Cardas Clear

Power                         Running Springs Dmitri

ModWright’s First Offering Revisited…

13 years ago, Dan Wright was building his first product, the SWL 9.0, named after his son and I had just begun my career of reviewing audio gear for The Absolute Sound.

I was building my first major system and wasn’t getting quite the sound I wanted. My ARC LS-3 was a bit on the thin side and my CJ PV-12 just a bit too warm for the rest of the components in my reference system (back then: a pair of ARC Classic 120 mono blocks, a pair of Vandersteen 2Ce’s and a Rega P25). Kurt Doslu from Echo Audio suggested a preamp from “the new guy in town,” Dan Wright.

It only took a quick listen to see that the SWL 9.0 was Goldilocks. i.e., it was “just right.” With simple, clean and understated aesthetics and amazing sound for the then $1,999 price, Dan Wright’s first effort was a winner. Had we given out Exceptional Value Awards in our first year or two, this product would certainly have won one.

Thirteen years later, the SWL 9.0 Anniversary Edition celebrates everything ModWright stands for: great sound, great build quality, and great value. And like a thirteen year old BMW 3-series, the original SWL 9.0s continue to delight audiophiles the world over.

Now that ModWright has broadened their product offerings considerably, the 9.0 SWL, according to Dan is “the perfect way to introduce music lovers to our brand for the first time.” Expect a matching power amplifier somewhere down the road, as Dan Wright is always brainstorming something new…

With the price only going up $900 in 13 years, the new SWL 9.0 has more functionality, better casework and incorporates everything they’ve learned in 13 years of building quality gear. Watch for our review in issue #78.

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