Tag Archives: audio research

Audio Research: Making the Music Glow by Ken Kessler

Where would the high end be without William Zane Johnson, the founder and, for better than forty years, chief designer of the Audio Research Corporation? Well, I’m not sure. Maybe in a year or two somebody just like Johnson would have come along. (He was one of those visionary figures so seminal to any movement that if he hadn’t existed, sooner or later, someone would surely have had to invent him.) But I can tell you for certain where I would have been as an audiophile in a world without WZJ: Nowhere.

Even though he was famously upbraided by an irate engineer when he introduced his Dual 50 tube amplifier at a trade show in 1970—“You’ve set the audio industry back 20 years!” the fellow shouted when he spotted all those old-fashioned glass-bottle 6L6s, 12AX7s, QA2s, and 6FQ7s sprouting from the chassis—the consumer world didn’t see it that way.

With the subsequent introduction of his SP-3 preamplifier in 1972—probably the single most important debut of the high-end era—WZJ changed everything: minds, prejudices, the market, the competition, the future. That preamp hit the audio world like a bombshell, provoking not just outrage from AES types wedded to solid-state but an agonizing reappraisal by audiophiles of exactly where that great new thing—the silicon transistor—for all its superior measurements and greater convenience had actually left them.

Oh, there had been plenty of stirrings of discontent in advance of ARC’s arrival on the scene. Early-gen transistor gear was, for the most part, terrifyingly unreliable and downright amusical. While pouring negative feedback on inherently nonlinear quasi-complementary circuits generated the great THD numbers that AES (and Stereo Review) loved, it was like applying a Band-Aid to a compound fracture. As Bart Locanthi would famously note when he developed the first truly symmetrical circuit for JBL’s SA-600 amplifier, an audio circuit has to be linear to begin with. Otherwise, negative feedback only exacerbates problems, rather than fixing them.

Many audiophiles, weaned on the great Marantz, McIntosh, Citation, and Dynaco tube designs of the Golden Age of Hi-Fi, knew that solid-state wasn’t right. Yes, it had measurably lower total harmonic distortion than tubes. But the distortion it did produce was odd-order, rather than the more pleasing even-order harmonic distortion of those disreputable glass bottles. Yes, glass audio didn’t have the sheer drivability of solid-state (the current and the low output impedance and the bandwidth); yes, it ran hot; and yes, its tubes eventually failed. But those tubes were fast and sweet and musical, and you didn’t have to use as much negative feedback (or any) to make them work.

For a whole lot of us, the better “specs” of solid-state—and the reviews in the mainstream audio magazines that paraded those specs as if they were all that mattered—had failed us. The bass of solid-state was good; the neutrality was good; the resolution was good. But the overall sound wasn’t. And then along came William Zane Johnson with his SP-3 and D-75 (followed by his D-76, D-76A, and D-150 amplifiers) to show us that tubes didn’t have to sound like the fat potatoes of the past—that they could be neutral, high-resolution devices, too. And that on acoustic music they could give us a level of realism and musicality that transistors couldn’t then approach, much less match.

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Original Resource is Articles – The Absolute Sound

Audio by Van Alstine DVA M225 Monoblock Amplifiers | REVIEW

I’m not gonna tease any of the readers by making them wait (or skip to my conclusion), so I’ll say right up front: OH. MY. LAWD.™ I was in audiophile heaven from the minute I [...]

Original Resource is Part-Time Audiophile

Wilson Audio SabrinaX Loudspeakers | REVIEW

Most audiophiles know of the unwavering commitment to accuracy and groundbreaking industrial design baked into the DNA of every Wilson Audio product (website), and the new Wilson Audio SabrinaX loudspeakers are no exception. This was first evident in Dave Wilson’s original assault on the state of the art with his WAMM design circa 1981, and other loudspeaker systems followed over the years. Along with advancements in materials science and simple but visually striking industrial design aesthetics, each loudspeaker system has a unique raison d’etre rather than simply various scaled-down models at different price points. Words and photos by Dave McNair Dave Wilson practically devoted his life to designing a speaker that would precisely reproduce what his ears (and mics) heard on his extraordinary recordings. His recording approach was a simple, purist style used to record musicians playing in natural acoustic spaces. It might seem simple, but there is nothing easy about this kind of approach. So it naturally follows that faithfully reproducing the recording of that event in a home listening room was his ideal. Today, Daryl Wilson and the rest of the great crew at Wilson Audio have maintained those same ideals and goals while simultaneously refining, improving, and [...]

Original Resource is Part-Time Audiophile

Audio Research unveils new vacuum tube amplifier, the Reference 80S

A ‘more affordable’ option to the 160s and 160m models.

Audio Research has released a new vacuum tube amplifier, called the Reference 80S.

Read more: The best high-end amplifiers

Designed as a ‘more affordable’ version of its larger Reference 160S and Reference 160M amplifiers, the Reference 80S features KT150 output tubes, with an 80-watts-per-channel output.

It includes XLR, SE, and RS232 inputs, alongside 4/8/16 ohm output tap, and 12V input/output triggers.

The amplifier also features an auto-bias circuit that can make adjustments based on both tube age and powerline voltage swings.

Priced at £14,998, the Reference 80S measures in 43.8cm x 25.4cm x 46.9cm,

Head here for more info.

Original Resource is The Vinyl Factory

Audio Research Corporation Reference 160S Stereo Power Amplifier

The Audio Research Corporation needs no introduction. Its foundational contribution to the audio world is well established. I have lusted after various ARC products over the last 35 years. Pretty much all ARC’s tube gear—from the 1987 SP9 preamp a neighbor owned when I was starting out to the more recent REF250 power amps, and many products in between—has fostered a kind of “inner life” within recorded music. The even more recent Reference 160M monoblocks vaulted my interest yet higher. When I heard them at industry shows and in audio shops, they sang with a clarity, finesse, and dynamic command that struck me as a new frontier for ARC. Now, we have the stereo version of the 160M—the $22k Reference 160S.

I didn’t have a pair of Ref160M ($34k) monos on hand for direct comparison, but with the stereo Ref160S in my system I did hear qualities very similar to those of the monos in other systems. This is no surprise, since the Ref160S has the same circuitry, tube complement (four KT150, two 6H30 per channel), and power rating (140Wpc) as the monos. The feature set is also the same—output-tube auto-bias, front-panel output-tube monitoring, ultralinear/triode-mode buttons, and “floating” power meters on a see-through faceplate. On the rear panel we have 4-, 8-, and 16-ohm taps, an output-tube hour-counter, a cooling fan control, an auto shut-off, and RCA/XLR input switches. The Ref160S is a bit larger in all dimensions (mostly depth) and weighs a lot more than a single Ref160M (100 pounds vs. 56 pounds), no doubt to accommodate two channels’ worth of stuff in a single chassis. (The only circuitry difference—as far as I can tell—is that the Ref160S shares one power transformer for both channels, whereas the 160M has, of course, one transformer per amplifier.) The stereo amp actually has a slight edge over the mono in aesthetics in my opinion: The 160S’s transformers are covered in their own nice-looking vented cage with the Audio Research logo on top, whereas the 160M has exposed transformers—if one removes its larger, “whole amp” cage cover to expose the tubes. The Ref160S also has two rear handles, which the Ref160M lacks, that make moving its 100-pound chassis easier. (For a more detailed explanation of the Ref160M/160S circuit and tube complement in the context of ARC’s development as a company, please see Executive Editor Jonathan Valin’s excellent Ref160M review in Issue 294. For more information about Audio Research Corporation as a company and its contribution to the audio arts, please refer to the ARC section in The Absolute Sound’s Illustrated History of High-End Audio, Volume Two: Electronics.)


Right from the start, the Ref160S had a wonderful, fluid, agile quality. Music skipped along with engaging litheness that did not immediately scream “classic tube amp,” in the sense of imparting a slight sluggishness on transients and some looseness in the bass. Actually, the Ref160S is the most powerful, nimble, and neutral-sounding tube amp I have had in my system. (For twenty years, until 2009, I used to run mostly new [not vintage] tube preamps and power amps exclusively.) The Ref160S combines just a touch of warm-side-of-neutral tonal balance with remarkably low—for a powerful tube amp—underlying noise, so it joins a group of tube gear from brands such as VTL, VAC, Lamm, Ypsilon, and Atma-Sphere that bucks classic tube amp sound in this regard.

Ref160S rear cover

In keeping with tubes’ typical strengths, the Ref160S had both midrange resolution and 3-D depth—both of the larger soundscape and of individual images—in spades. Though not quite as extended at the extremes as some good solid-state amps, it also expanded midrange resolution to the immediately adjacent parts of the frequency spectrum—to a degree that helped everything sound more realistic and less obviously “tube-processed.” Mind you, the Ref160S’s top end was a little softer than I am used to from the solid-state amps (Gamut, Constellation, Hegel) I have been recently using, but I did not get the sense that I was missing much sonic information when I considered the whole picture. In fact, the Ref160S reproduced the gestalt (as TAS founder Harry Pearson liked to say) of a full orchestra in a way that made me think, “Wow, that gets a lot of it right!”

It may seem like a conundrum, but the Ref160S had such a low noise floor and its image boundaries were so free of “electronic etch” or “fizz” that its upper frequencies might strike some listeners as missing the last bit of extension and information, compared to certain other amplifiers. But the Ref160S actually made music sound more lifelike, to my ear, than most other amplifiers in terms of its refined image outlines and lack of electronic grain. Maybe it was the sense of continuousness that tubes bring to bear, or the midrange lucidity, or the sense of physical presence, or the wonderful musicians-in-a-hall effect with their trailing tails of notes lingering in space a bit longer (all of which the Ref160S does so well) that contributed to an overall “reminiscent-of-live” impression. Because of this truly fine realistic quality, I was motivated to revisit some of my classical LP collection: the Poulenc Concerto for Strings, Tympani, and Organ [Erato], Canteloube’s Songs of the Auvergne [EMI], and Mozart’s Concerto No. 21 in C Major [Phillips] were reproduced with remarkably natural-sounding details and immediacy. I found new aspects of the performances’ phrasing and developmental arc—new “musical meaning,” if you will—with the Ref160 in play. (Choreographers Glen Tetley [Voluntaries], Leslie Jane Pessimier, [Les Chansons] and Jiří Kylián [Petite Mort] used the music listed above, respectively, to create wonderful neo-classical dance works, by the way.)

Pop and rock had forward momentum in a parallel to the lucid gestalt in classical music. There was plenty of transient snap and power to give well-recorded drum kit, for example, the sense of acceleration that well-recorded drums contribute to the mix. I didn’t hear the Ref160S’s musical appeal across different genres as overtly euphonic as such; rather, the Ref160S simply brought out elements in recordings that illuminated the artistic expression inherent in music more readily—provided the recordings had decent performances and were well recorded in the first place, of course. It was as if the musicians had a particularly good night at the concert hall, club, or recording studio. We have probably all attended a live performance on one evening and then heard the same group or orchestral program again on another night and regarded one evening’s performance as better than the other. The players were clicking more with each other or the singer was in particularly good voice or the sound engineer got the levels and microphones’ phase-matching right. The Ref160S seemed to have the effect of making home listening sessions come closer to a superior evening’s performance. When one of my long-time audiophile friends said upon hearing a few cuts through the Ref160S, “Wow, the music sounds really alive—I could easily live with that amp,” I got it.

The Ref160S had a very deep soundstage, the deepest I have heard in my system. Front-to-back layering was continuous and closer to real life than many amps can muster, especially amps of the solid-state variety. Images within the soundscape were fleshed out as more completely formed sound sources created by real people and instruments in space, rather than as flat cutouts or bas-relief tableaux. The front of the soundscape was moved more forward than I am used to, so this—combined with slightly narrower soundstage width—created an overall stage that was sometimes closer to a cube in shape than to a rectangle whose width is greater than its depth. I suspect some of the amp’s slightly narrower soundstaging could be the result of the Ref160S being a stereo amp rather than a monoblock. (All things being equal, a pair of monoblocks tend to cast a wider soundstage than the equivalent stereo version.) Also, I believe the Ref160S is meant to be paired with an ARC preamp, like a Ref10 or Ref6SE, which themselves recreate very wide, expansive soundscapes. (Unfortunately, an ARC preamp was not available during the review period to test this hypothesis.)

Bass was deep reaching and powerful. The Ref160S’ plumbed the depths with ease, not exactly a typical tube amp’s forte, especially when one considers the speaker I used was the YG Sonja 2.2, which generally fares better with a high-current solid-state amp. While not quite matching the speed and definition of some solid-state amps, the Ref160S had the best bass pitch definition and stability of any tube amp in my system. Dynamics were also very good, both macro and micro. The big, meaty sound the Ref160S produced stemmed, in large part, from its ability to track bass-laden dynamic peaks with sustained control. The Ref160S never clipped or showed signs of strain while in ultralinear mode. It did lose control and clip, however, on the big orchestral stuff while in triode mode (70Wpc).  I think most folks who listen in triode mode would presume it is better suited to smaller, less demanding music (or to an easy-load speaker). Speaking of triode and ultralinear modes, I did nearly all of my listening in ultralinear. While the triode mode did offer some additional warmth and intimacy on smaller-scale music, I didn’t find the difference compelling enough to be worth switching back and forth between the two modes on appropriate music selections. On the whole, I found ultralinear to sound tonally closer to neutral and more dynamically responsive.

The Ref160 gives off a lot of heat, but that comes with powerful tube-amp territory. ARC uses cooling fans to keep operating temperatures within optimal range and extend tube life. Since I placed the Ref160S in front of my equipment rack to make connecting it to and from my system easier, I did hear the fan during very quiet music passages, even with the fan speed set to low. I believe most users would place the amp in a more room-friendly position, and that would, no doubt, be farther away from the listening position. Let me add, the Ref160M/S aesthetics are a welcome change for ARC whose typical look has tended to be more industrial and functional. I liked the see-through faceplate, but I turned off the lighted VU meters, as I found them to be a little distracting. A friend thought they looked really cool and wanted to see them with their light level all the way up. (There are three levels plus off.)


The winning combination of a low noise floor, which allows details to emerge in an unforced way, and very high levels of image solidity, which produces a closer-to-live listening experience, is central to the Ref160S’s appeal. Add in uncommonly good bass presence and dynamic control, and you have a tube amp that goes a long way to furthering the strengths of valves while mitigating their typical weaknesses.

To my mind, the Ref160S doesn’t try to sound like a solid-state amp as such; it is, rather, a high-quality amp in its own right, and can outperform most solid-state designs in depth layering and musical fluidity. If you feel like venturing into the glories of tubes or continuing your tube amp adventures on a different plane, consider the Ref160S. It is highly recommended.

Specs & Pricing

Tube complement: Two matched pairs KT150; two 6H30 per channel
Power output: 140Wpc (20Hz–20kHz)
THD: Typically 1% at 140 watts, below 0.04% at 1 watt, 1kHz
Power bandwidth: 5Hz to 70kHz (–3dB points)
Frequency response: (-3dB points at 1 watt) 0.5Hz to 110kHz
Input sensitivity: 2.4V RMS balanced for rated output
Gain: 25.5dB into 8 ohms
Input impedance: 300k ohms, balanced; 100k ohms, single-ended
Output taps: 16 ohms, 8 ohms, 4 ohms
Damping factor: Approximately 14
Overall negative feedback: 14dB
Slew rate: 13 volts/microsecond
Rise time: 2.0 microseconds
Dimensions: 19.0″ x 10.25″ x 21.5″ (with handles and connectors: 24″)
Weight: 100 lbs. (net)
Price: $22,000

6655 Wedgwood Road North, Suite 115
Maple Grove, MN 55311
(763) 577-9700

Associated Equipment
Analog source: Basis Debut V turntable & Vector 4 tonearm, Benz-Micro LP-S MR cartridge
Phonostage: Simaudio Moon 610LP
Digital sources: Hegel Mohican CDP, HP Envy 15t running JRiver MC-20, Hegel HD30 DAC
Linestages: Ayre K-1xe, Hegel P30, Constellation Audio Virgo III
Integrated amplifier: Hegel H390
Power amplifiers: Gamut M250i, Hegel H30
Speakers: YG Acoustics Sonja 2.2, Raidho TD1.2, Dynaudio Confidence C1 Signature
Cables: Shunyata Sigma signal cables, Nordost Heimdall 2 USB, Shunyata Alpha S/PDIF and AES/EBU, Shunyata Sigma NR and Omega XC power cords
A/C power: Two 20-amp dedicated lines, Shunyata SR-Z1 receptacles, Shunyata Everest 8000 and Typhon power conditioners
Accessories: PrimeAcoustic Z-foam panels and DIY panels, Stillpoints Ultra SS

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Original Resource is Articles – The Absolute Sound

RCM Sensor 2 MKII Phono Preamplifier | REVIEW

RCM Sensor 2 MK II Phono Preamplifier Words and Photos by Dave McNair I’m one of those audiophiles that started my listening obsession with vinyl records. You know, those flat round black things that sound amazing unless they don’t. I love records. I hate records. It’s all so confusing. Listening to records using the RCM Sensor 2 MK II phono preamp takes all that confusion away. As a recording engineer (now mastering engineer) who started during the heyday of magnetic tape and polyvinylchloride disks, I’ve had a front-row seat to the arc of technology for recording and playing back music. At some point, records and tape disappeared from my listening habits and I stopped caring about what medium was employed in service to the music. That changed when I bought a turntable about four years ago and started listening to records again.Long about this time, as an addition to my mastering business I decided to get into the anachronistic and lunatic fringe world of lacquer cutting for vinyl record production. This insane decision was fueled by my rediscovery of vinyl. Which of course required me to upgrade my home system to check the quality of my cutting work right? What [...]

Original Resource is Part-Time Audiophile

Audio Research to Release Book for 50th Anniversary

MAPLE GROVE, MN — I’ll be honest. I’d probably buy this book just because Ken Kessler wrote it. Enclosed below a press release and more juicy book photos. Enjoy! AUDIO RESEARCH RELEASES ‘AUDIO RESEARCH: MAKING THE MUSIC GLOW’ BOOK TO CELEBRATE 50TH ANNIVERSARY The Definitive Luxury History Book, Describes the Past, Present, and Future of the Audio Company’s Legacy Audio Research is honored to partner with author Ken Kessler in releasing a book timed to the company’s 50th anniversary. Entitled, “Audio Research: Making the Music Glow”, the book describes the people behind the company, designing, manufacturing, fine-tuning, and marketing the audio amplification and source components that have been regarded perpetually as among the best in the industry. Celebrating its first half-century, the book tells the story of a manufacturer that helped define high-end audio, with the sole purpose of elevating the sound quality of music in the home. William Zane “Bill” Johnson established Audio Research in 1970, basing its products on what was then considered by many to be obsolete technology: vacuum tubes. Guided by his passion for music and quality listening with a refusal to fall victim to fashion and design trends of the times, Johnson was revolutionary in [...]

Original Resource is Part-Time Audiophile

Audio Research CD6 SE Compact Disc Player/DAC | Review

When’s the last time you heard a new CD player and thought wow, this sounds terrific? I’m not talking about digital in general or a DAC, but a one-box CD transport/DAC playing just a redbook CD. That happened to me with the very first CD I listened to with the Audio Research CD6 SE. When we talk about advances in digital technology, in most cases we’re talking about DACs. We’ve seen plenty of innovative DACs over the last few years, usually employed in conjunction with high-resolution files and streaming from our favorite services. As far as “ordinary” CD players go, I feel like we hit the ceiling a few years ago. Most of the top-notch CD players over the last few years sound very similar, in my opinion—you play a disc and you think yeah, this sounds right. It’s been a long time since I bought a new CD player and thought it sounded much better than every player I’d heard before. I can probably go back close to 20 years ago, when I bought a Naim CDX2 and thought it couldn’t get any better. From those first few seconds with the Audio Research CD6 SE, I had that feeling [...]

Original Resource is Part-Time Audiophile

AudioQuest Niagara 1200 and 3000 Power Conditioners | Review

At a recent high-end audio show I sat with a group of colleagues in the hotel lobby and discussed, as we often do, what we had seen that was worthwhile. One person asked an interesting question: “What single component are you seeing in more rooms than any other?” I made a joke about Mat Weisfeld pulling up in a truck full of VPI turntables and dropping one off in every room, but then I realized that the answer was this: the AudioQuest Niagara power conditioners, specifically the flagship Niagara 7000. In a very fickle industry, that says a lot about the AudioQuest power conditioning designs—even if Bill Low and Garth Powell are just pulling up in the space next to the VPI truck and installing Niagaras in each room the Wednesday before the show. It means that there’s a consensus in the high-end audio industry, a rare thing. Or it could mean that AudioQuest is simply a generous company when it comes to loaning out product. I can attest to the latter possibility—AudioQuest is always willing to lend me anything I need to do my job, no questions asked. Stephen Mejias, well-known to most audiophiles as a former reviewer and [...]

Original Resource is Part-Time Audiophile

Audio Research Makes Updates to the LS28SE Preamplifier | Announcements

Just a couple of weeks after finishing the review on the extraordinary Audio Research CD6SE compact disc player/DAC (review to appear in late June), I received this press release from ARC on the new LS28SE preamplifier: UDIO RESEARCH ANNOUNCES SPECIAL UPDATES TO LS28 PREAMPLIFIER The Company Will Release an SE Performance Update to the LS28 Line-Stage Preamplifier   MAPLE GROVE, MN – June 8, 2020 – Audio Research is pleased to announce important performance updates to its award-winning LS28 preamplifier as a part of their 50th Anniversary product line improvements. The new LS28SE is priced at MSRP $10,000 each (€11,500 each VAT Included) and will replace the LS28, with shipments beginning June 2020. The improvements in the LS28SE stem from what was learned during the creation of Audio Research’s Reference 160-series amplifiers.  Very similar to the wire and parts changes incorporated in the REF6SE and REF PH3SE, the LS28SE also includes upgrading to the same proprietary gold coupling caps used in the REF6SE. These numerous and costly component upgrades elevate the LS28SE’s performance to an entirely new level. The improved clarity, resolution, transient snap, sense of space, and a relaxed purity are instantly noticeable and will inspire extended listening sessions. Customers will be able [...]

Original Resource is Part-Time Audiophile