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Equipment Review
June 2002

Audio Research SP16 Preamplifier

by John Crossett

"Continues Audio Research’s tradition
of trend-setting preamps and shows that  William Z. Johnson’s ideas on superb  
sound are as valid as ever."

Reviewers' Choice Logo


Exceptional Value

Review Summary
Sound Low noise and low editorial effects, which increase retrieval of low-level detail, "thereby rendering the music in a more believable way"; "Soundstaging and depth were both impressive," as was the SP16's rendering of "instrumental tone."
Features Fully remote controlled clean layout -- no knobs or switches on the front panel; uses six 12AX7EH tubes: three in the line and phono stages.
Use No balance control or balanced inputs or outputs; phono stage is a $500 option.
Value "I doubt you’ll find an all-around better preamp in the $2000-$2500 price range."

How many of the grand old names of high-end audio continue to derive their vision and drive from the man who founded the company? Foremost among those select few would be Audio Research Corporation and its visionary founder, designer, chief cook and bottle washer William Z. Johnson. For over 30 years, owning any piece of Audio Research equipment has always guaranteed you a certain amount of prestige and the assurance you'd be hearing music just as Bill Johnson thought it should be reproduced.

Audio Research first came to prominence as a company that continued to champion the use of vacuum tubes as viable music-making devices, even in the face of the industry's massive switch to transistors. ARC has, nevertheless, continued to keep up with the times. It’ll only take one browse through their website to witness the dizzying array of products they produce: tubed, hybrid, and solid-state (in an abundance of price ranges), all designed to bring the consumer the most music and reliability for the price. Preamps such as the SP3, SP6, SP9, SP10, and SP11 set the standard for their times (and sometimes beyond), and this tradition continues with the introduction of the all-new, all-tube, full-function, remote-controlled SP16 preamplifier, priced at a relatively affordable $2495 USD -- $1995 without phono stage.


Audio Research equipment has always had an understated yet elegant style, and the SP16 is no exception. It isn’t beautiful in a Guggenheim Museum sort of way, but it looks every inch an Audio Research product. The only thing that differentiates the SP16 from previous ARC efforts is the absence of rack-mount handles as well as all knobs and switches. What, no knobs or switches? That’s right -- none. Across the silver or black aluminum faceplate are two large black rectangular panels. The left panel contains LEDs for Mute, Processor, Stereo/Mono, Input (of which there are six: Phono, CD, Tuner, Video, Aux, and Processor) and Volume. The right offers six push buttons: Power, Mute, Processor, Input, and Volume up and down (with 70 different settings). The only omission to an otherwise well-conceived preamp is the lack of any sort of balance control. I do miss this feature, but not to the point of dismissing the SP16.

Around back, things are just as uncluttered. You'll find six sets of gold-plated RCA input jacks, three pairs of identical output jacks (two main, so connecting to a subwoofer or biamping is easy, and a tape out), a tonearm ground connection if your SP16 has its phono stage, an IEC power-cord receptacle, and a fuse holder. Once again, simplicity rules. The small, yet functional remote offers all the same front-panel controls as well as your only access to the Stereo/Mono switch. Audio Research is kind enough to include a set of batteries for the remote, a nice touch. The black metal case is perforated on the top and bottom, the better to increase ventilation for the six 12AX7EH tubes within: three in the line stage and three in the phono. High-quality ARC-specified parts are used inside, and the layout is very clean.

The SP16 is slightly larger than my vintage SP6A, due to the body now being the same size as the faceplate, but less heavy. It measures 17 3/4"W x 5 1/4"H x 10"D and weighs 12.6 pounds. The SP16's phono stage is designed for moving-magnet or high-output moving-coil cartridges only, so leave those exotic cartridges elsewhere. But then, at the SP16's price, this is what I would expect. When I turned the unit on, the auto-mute circuit kept everything quiet for 30 seconds, all the better to keep unwanted rude noises from heading straight for, and possibly damaging, my speakers. Using the SP16 was a breeze, and boy did the couch potato in me love the remote control!

Sonic impressions

Right out of the box, the SP16 displayed a sound different from that of my SP6A -- no surprise, I guess. It was more bold and vivid, more front row. Instruments were delineated in a much better manner, and I noticed more space around those instruments too. If the SP16 offered all this when it was brand new and cold, what would a fully broken-in unit sound like? Hmmm.

Well, to answer my question, I went about playing music through the SP16 for approximately two weeks before settling down for my first serious listen. At least that’s what I tried to do. All too often I found myself just falling into the music. My notepad was blank, and I was too busy listening and enjoying myself to think of doing anything else. This was a good sign. If I can become so engrossed in the music being delivered by a new piece of equipment, to the detriment of critical listening, maybe, just maybe, it’s doing what it's supposed to: not add anything much of its own signature to the signal being passed through it.

Associated Equipment

Loudspeakers – Magnepan MG1.6/QR.

Amplifier – Sunfire Stereo.

Preamplifier – Audio Research SP6A.

Analog – VPI HW19 Mk IV turntable w/ Super Arm Board and VPI VTA adjuster, Butternut Audio-modified Rega RB300 tonearm, Clearaudio Aurum Beta S and Sumiko Blue Point Special cartridges.

Digital – Rega Planet 2000 CD player.

Interconnects – Harmonic Technologies Pro-Silway II, Goertz Alpha-Core Triquartz, and DH Labs BL-1.

Speaker cables – Goertz Alpha-Core MI2.

Accessories – Target rack, homemade sandboxes, Golden Sound DH Cones and Squares, VPI 16.5 record cleaner, Michel Tenderfeet (under turntable).

All right, you and I both know that every piece of audio equipment adds something to the musical signal. That’s one of those inescapable truths of audio. But the better gear seems to add less to the signal than poorer gear does (and that’s true regardless of price). The SP16 is a very good piece of equipment, for it seems to add less to the sound of my system than any preamp I used previously. The line stage was dead quiet, and I had to stand right next to one of my speakers to hear any noise from the phono section, quite a feat for such an affordable piece of tube equipment. This lower noise floor added much to my listening pleasure. It allowed more of the low-level detail on my recordings to be heard, thereby rendering the music in a more believable way. The suspension of disbelief that is so important when an audiophile listens to music was made easier by the SP16.

For instance, I dropped Andy McCloud’s Blues For Bighead [Mapleshade 07832] in the Rega CD player, and there was drummer Victor Jones clearly keeping time by tapping his foot on some sort of wooden platform. I could hear the hollow echo of the cavity under his drum kit each time he tapped his foot, this while the music was playing. Impressive. So too was the retrieval of space. I was suddenly presented with a recording I thought I was already intimately familiar with, but I wasn't. For an example of the inner detail brought forth by the SP16, I listened to Lee Konitz's Alone Together [Blue Note CDP 7243 8 57150 2 0]. I could now hear clearly the buzz of Konitz's mouthpiece as he blew through the reed. Konitz’s tart alto sound was clearly evident, and there was a marked contrast between it and the sound of a tenor sax, both in size and tone. And as with the McCloud disc, I could better make out the acoustics of the club and the relationship of the bandstand to the audience.

Soundstaging and depth were both impressive via the SP16. A disc that I’ve come to rely on for a demonstration of these qualities is the Clifford Jordan Quartet's Live At Ethell’s [Mapleshade 56292]. Each of the four musicians on this recording was in his own acoustic space behind, even with, or in front of one another, depending on his spot on the bandstand. Space is rendered as recorded, no editorializing.

As for instrumental tone, again the SP16 exceeded my expectations. Bass was full, if not necessarily as deep as it could be. But what’s there is very well defined. Dave Holland’s upright bass on the Joe Henderson CD So Near, So Far [Verve 314 517 674-2] was easy to follow, as were all the subtleties of his playing. On the other end of the spectrum, cymbals, triangles and such were rendered with the appropriate shimmer. The SP16 may not offer the last word in treble extension, but its high frequencies are well balanced with its bass and represent a very well-thought-out set of tradeoffs.

The midrange of the SP16, wherein lies most of the music, especially voice, was wonderful. Playing the newly re-mastered Carmen McRea CD, Carmen Sings Monk [Bluebird 09026-63841-2], brought out all the strengths of this preamp. The subtle details that made the recorded space of the live tracks distinctly different from that of the studio cuts were clearly evident. And McRea was there, in my listening room, singing to me. She was fully fleshed out, not just some disembodied voice that sounded a little like Carmen McRea.

The SP16's phono stage is as good at the retrieval of musical detail as the line stage. Personally, I much prefer a built-in phono section to an outboard one, what with factoring in the purchase of a set of quality interconnects and having to find an extra shelf on which to put it. The tubed phono stage of the SP16 was a vast improvement over that of my SP6A, keeping in mind that both units use the same tubes. The SP16 was quieter, more detailed and more, well, musical. I’d stack it up against any $500-$800 outboard phono stage available, tube or solid state.

Listening to my copy of the Chesky LP reissue of Rimsky-Korsakov's Scheherazade [Chesky RC4], I was amazed again at the added dimensions of the soundstage. The Chicago Symphony Orchestra was laid out before me with more width and depth than I’ve heard in my system before. It was now a simple matter to "ear"-ball the location of each section of the orchestra. And the added width and depth continued into the furthest reaches of the soundstage too, no triangular-shaped space here.

The song "That’s The Way That The World Goes Round" from John Prine’s Bruised Orange [Asylum 6E-139] begins with Prine flubbing a note on his guitar then turning to the band and joking about it. With good preamps, I could always tell that the band was indeed behind Prine. But the SP16 showed me the minute differences in the volume of Prine's voice as he turns away from the mike and toward the other musicians. The SP16 also gave Prine’s acoustic guitar more body, while still keeping the sound of his fingers plucking the strings.

Even with all of my praise, I know the SP16 is not the be-all and end-all of preamps. If it were, Audio Research would discontinue the Reference Two Mk II, and they’re not. There are better preamps out there, but you’re going to be shelling out a lot more green for them, and perhaps just to retrieve a small amount of extra information. The SP16’s lack of a balance control and provision for low-output MC cartridges may be cause for concern for some potential buyers. Still, despite the SP16's omissions, I doubt you’ll find an all-around better preamp in the $2000-$2500 price range.

Old vs. new

One of the enjoyable aspects of this review was being able to compare my mint Audio Research SP6A with the SP16. Both of these preamps use 12AX7 tubes and are full-function units. So just how much progress has Audio Research made in the 24 years since the SP6 series made its debut? Would it be worth your while to consider upgrading?

I’m not going to beat around the bush -- the SP16 is far and away the superior preamp. Both may use the same tube complement, but it was apparent from my first listen that in the SP16, ARC has increased the performance of its affordable preamps. All aspects of sound were improved in a significant manner. The background that the music appears to emanate from is blacker with the SP16, the soundstage is wider and deeper, and air surrounding the musicians and via the recording venue itself is far more apparent. And the instruments themselves are more three-dimensional.

And it’s not just the sonics that have improved. The ergonomics are better too. Gone are the switches and knobs that could become dirty and non-conductive. Instead, you get remote control and pushbuttons. Gone, too, are the outlets on the back and the possibility of contaminated sonics they added to the sound of the SP6A.

So yes, Audio Research has made large strides in the intervening years since my SP6A was new. I would say that it should only take one listen for you to reach this same conclusion.


The SP16 is not the world's best preamp, if such a thing even exists, but then I never expected it would be. I did think it should be an improvement over older ARC preamps and equal to (or better than) its modern counterparts, and to my ears it is. It does all the things a good preamp should: be quiet, get out of the music’s way, offer all the features I want (well, almost) and be easy to use. But above all of these, the SP16 played music in ways that were consistent with what I hear live. It brought new insights and excitement to every CD and LP I played through it, and I played quite a few over the course of this review. It made poor recordings tolerable and good recordings sound good. And it made great recordings sound, well, like the reason we became audiophiles in the first place.

If you are like me and using an older preamp, or if you are moving up to separates from an integrated amp (or even a receiver), the SP16 could very well become the centerpiece of your new system. Listen to it, use it, and listen to it again. While it’s not exactly inexpensive, it is very affordable in terms of tube preamps. And I think you’ll be pleasantly surprised at the level of performance, build quality, and convenience available to the audiophile on a relative budget. The SP16 continues Audio Research’s tradition of trend-setting preamps and shows that William Z. Johnson’s ideas on superb sound are as valid as ever.

...John Crossett

Audio Research SP16 Preamplifier
$1995 USD, phono stage adds $500.
Warranty: Three years parts and labor.

Audio Research Corporation
3900 Annapolis Lane North
Plymouth, Minnesota 55447
Phone: (763) 577-9700
Fax: (763) 577-0323

Website: www.audioresearch.com

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