Innovation in Design

Review Summary Sound "Its own noise floor is exceedingly low -- below audibility, really -- which helps it uncover the lowest level of detail in a way that's unmatched in my experience." It also has "a very forceful, immediate presentation that… makes for exceedingly wide dynamic range." "There is also a weightiness, especially in the bass, which has great depth and power." Features "The Tube is a fully balanced line-stage-only preamp with a few twists. Only nine of the unit's 19 tubes are used for the main line-stage circuit…. The other ten tubes are used at The Tube's inputs -- five inputs, one tube for each channel. Each input has its own separate self-contained circuit, none of which is inactive or out of the preamp's main circuit.… Instead of the selector switch choosing which input's signals are routed through to the outputs, it instead turns on the heater supplies of the pair of tubes for the chosen input." Use "Because each input has its own pair of tubes, The Tube allows experimentation and fine-tuning like no other preamp. You can pick the input tubes that sound best for each source." "The minute-long delay as the tubes for the current input come to life and those for the previous one die out makes quick switching among inputs an impossibility." Value "I suspect that for some listeners, its clear, forceful sound will make it the obvious choice, even at its considerable price."

High-end audio is filled with unusual products that are often labeled "revolutionary" or "innovative" when, in fact, they are more like their peers than different from them. Each has to perform a certain number of set functions, so the room for true novelty is small. It is often most outwardly represented by a nearly superfluous feature or unique appearance. Yet it is the differences among audio products that separate one from another, especially in the minds of audiophiles, who, at their very core, are not interested in mass-market concerns.

While Einstein's The Tube looks on paper to be just another remote-controlled stereo preamp, some investigation proves that it is a thoroughly original design. The company behind it is located in Germany, where its products have been manufactured for 15 years. Two years ago, Aaudio Imports of California began distributing the Einstein product line in the US, which certainly increased the company's exposure. Currently, Einstein manufactures a CD player, a preamp, three amplifiers, an integrated amp, a phono stage, and a remote control. Each of its products has a rather demonstrative name, and all of them (except for the aptly named The Remote remote control, and The Turntable's Choice phono stage) use tubes, often a generous number of them. The Tube preamp, for instance, has a total of 19 tubes, each of which enhances the look of its gleaming black-and-silver exterior.

But it's how those tubes are used in The Tube's case that makes it unique. The Tube is a fully balanced line-stage-only preamp with a few twists. Only nine of the unit's 19 tubes are used for the main line-stage circuit. Eight of these are 6922/E88CC dual triodes; there is also a single 12AU7/ECC82. The other ten tubes are used at The Tube's inputs -- five inputs, one tube for each channel. Each input has its own separate self-contained circuit, none of which is inactive or out of the preamp's main circuit. In normal circumstances, if all of the inputs are effectively live, signals from each would occur at preamp's output. However, The Tube doesn't represent any kind of normality. Instead of the selector switch choosing which input's signals are routed through to the outputs, it instead turns on the heater supplies of the pair of tubes for the chosen input. Therefore, only the signal from that input is live.

This has some interesting implications. First, while you can switch quickly among the various inputs, The Tube takes a minute or so to produce music from any one that has just been selected. Signal from the previously chosen input slowly fades out as the signal from the new input is heard. Second, because each input has its own pair of tubes, The Tube allows experimentation and fine-tuning like no other preamp. You can pick the input tubes that sound best for each source. Like the sound of rare Telefunkens with your CD player and NOS Mullards with your phono stage? No problem for The Tube.

As I've already hinted, The Tube is a dramatic-looking component, though rather compact for a preamp: 17"W x 6 1/4"H x 15 1/2"D and 33 pounds. Its price isn't compact at $13,850 USD. It comes standard with two single-ended inputs, three balanced inputs, and balanced outputs, but you can order it with single-ended outputs as well. In front are the volume and input knobs along with a window for the remote-control sensor and an LED that lets you know The Tube is on. There's not much space on the narrow back; accordingly, the IEC power-cord inlet is on the bottom of the preamp and near the front. It requires a power cord with a 90-degree connector. Aaudio supplied a heavy Isoclean Focus cord ($1000) for my use. A tube cage is standard equipment, and while it isn't exactly attractive, leaving it in place doesn't mar the look of the preamp, because the faceplate hides it from the front.

Design highlights aside from those already mentioned are the ubiquitous short signal path along with a volume control that is outside the signal path. This last feature may help explain one of The Tube's most amazing feats: its utter lack of tube noise. Connect it to even a high-gain amp like the Lamm M1.2 Reference, and you hear only the amp's own noise when you put your ear up to the tweeter. The Tube is as quiet as the very best solid-state preamps -- as quiet as an undiscovered tomb.

The remote supplied with The Tube is obviously a generic one. It looks like it's meant to control a DVD player -- it has many buttons, only a few of which work with The Tube. There are separate buttons for each input and volume up/down. The remote doesn't befit a nearly $14k product, but it does work as described. In terms of its feature set, The Tube is less robust than the Audio Research Reference 3 with its vacuum-fluorescent display, and a far cry from the VTL TL-7.5 (now in its Series II iteration) and Mark Levinson No.32, both of which are packed with user niceties.

But as its novel circuit and all those tubes indicate, The Tube is not about ergonomics. It's optimized for sound, with remote control being a concession to user friendliness and not a primary consideration in its design. While the volume control works as billed, the minute-long delay as the tubes for the current input come to life and those for the previous one die out makes quick switching among inputs an impossibility.

Review system

I used The Tube at two different times a few months apart. This gave me the opportunity to pair it with an extraordinarily wide selection of ancillary electronics, although the speakers in both stints were Wilson Audio Alexandria X-2s. Amplifiers were Lamm ML2.1 and M1.2 Reference monoblocks, along with a Blue Circle BC204 stereo amp and a pair of BC208 monoblocks. Sources included Esoteric X-01 and X-01 Limited CD/SACD players, Audio Research CD3 Mk II and Reference CD7 CD players, an Ayre C-5xe stereo universal player, and a Zanden Audio Model 2000 Premium/Model 5000 Signature transport/DAC combo. The preamp for comparison was an Audio Research Reference 3.

Interconnects and speaker cables were primarily Shunyata Research Antares Helix and Orion Helix. Even as I use other sets of cables, the Shunyata cables are the ones I keep coming back to, as they tell me a great deal about the equipment under review and sound wonderful doing so. Although I experimented with single-ended connection, I used the equipment balanced for 90% of my listening. Especially with the fully balanced sources I had on hand, this simply made for the best sound.

Power conditioning was the job of a Shunyata Research Hydra Model-8, which has become a fixture in my system. Power cords were from Shunyata Research (Anaconda Helix Alpha and Vx, Python Helix Alpha and Vx) and Essential Sound Products (Essence Reference). A properly outfitted Essence Reference or Python Alpha would work with The Tube and its bottom-mounted power-cord inlet, but the thick diameter of an Anaconda power cord might not pass beneath the chassis.

A sustained "Wow!"

There are many ways in which reproduced music gets very close to the sound of live, but a couple where it still lags far behind: dynamics and weight. Whenever I hear live music, I am struck by how much greater its dynamic range is -- from barely audible to deafening -- and how heavy and dense the presentation is, especially with amplified music. These things aren't easy for reproduction to equal. The noise floor of audio electronics will never be as low as that of live music, and the volume needed to convey that sense of weight is hard to achieve at home, all the more so given that microphones and other recording equipment only capture a facsimile of the live event.

Yet, it is in these two areas that The Tube preamp excels. Its own noise floor is exceedingly low -- below audibility, really -- which helps it uncover the lowest level of detail in a way that's unmatched in my experience. Coupled with this is a very forceful, immediate presentation that, along with that non-existent noise floor, makes for exceedingly wide dynamic range. There is also a weightiness, especially in the bass, which has great depth and power, that will have you pulling out some of your favorite recordings just to hear what they sound like with The Tube.

The true demo-quality sound of the 24-bit/192kHz Soular Energy DVD-A [Hi-Res Music HRM 2011] was apparent with The Tube in my system. Ray Brown's bass on "Exactly Like You" showed the bursts of speed and power of a world-class athlete. This was one of the first tracks I played with The Tube in my system, and it made me blurt out "Wow!" without even thinking about it. Such a reaction can be a good thing if its source sustains itself from recording to recording, and it can be a bad thing if it doesn't, which usually signals one of two things: an artifact from a recording mating in an exciting new way with the review product, or an emphasis somewhere in the product's sound that seems exciting at first but wears out its welcome over time. Neither turned out to be the case with The Tube -- thankfully. The preamp's presentation, while having some distinct identifying marks, was easy to like over the course of time, even as I changed ancillary equipment. Moreover, I blurted or thought "Wow!" more than a few times while The Tube was in my system, a sign of very good things.

The Tube's soundstage radiates around and behind the speakers, but its forward-most plane is closer to the listener than that of other preamps I've had in my system over the past several years. This creates a clear and muscular presentation that mated well with all of the amps I had on hand, especially the Lamm ML2.1 SET monoblocks. The music was always vividly rendered; speed and punch did not disappear at low listening levels. This all led me to believe that you will not want to mate The Tube with a forward-sounding amp that emphasizes leading-edge definition over the music's corporeality. This will eliminate many solid-state amps and all lean-sounding tube amps. The Tube would also require careful matching with many horn-loaded and single-driver speakers, whose crisp highs and papery midrange would have nowhere to hide. On the other hand, the high sensitivity of such speakers would benefit greatly from The Tube's lack of noise, and I can imagine that with the right high-sensitivity speakers and (probably tubed) amp, it would be the ideal preamp.

The bass can be a challenge; my uncertainty is due to the way the rest of the system, especially the speakers, loads the listening room. With The Tube, there is great depth, power and slam, along with the realistic way the bass frequencies spread throughout the room, imparting a physical dimension to the music. In fact, The Tube is better at this last thing than any preamp I've heard no matter its technology. However, all that low-frequency energy can overload a room too, a glimpse into which I was able to get when I played "Joe Slam and the Spaceship" from Harry Connick's She [Columbia CK 4376]. The Wilson X-2s were literally vibrating walls all over my house when the opening low tones entered. Yes, I was leaning on the volume, but the only time I had experienced such bass authority was in David and Sheryl Lee Wilson's huge listening room, again courtesy of the X-2s. The Wilsons' house is made of stouter stuff than mine -- and perhaps yours. I am lucky to have a large room -- 20'W x 29'L x 10'H -- with no obvious bass anomalies; yet, The Tube and the X-2s turned the walls into snare drums. If your full-range speakers are in a smaller room than mine, and especially if the room has low-frequency issues, your reaction to The Tube's low-end prowess may turn from surprise and delight to dismay.

The Tube is the alpha male of line-stage preamps, but even with all of this talk of immediacy and power, it doesn't miss the little things. Just as with the big shifts in volume, the smaller shifts are handled very well -- along with all of the fine detail buried in each recording. Delicate music -- chamber music, small-ensemble jazz -- is served up with its subtlety and quietude intact, even enhanced. Play a great recording, and you immediately know why it's great, and perhaps think it sounds better than you've ever heard it before. Play one that's so-so and you may hear things normally submerged in the noise floor of other preamps. Play one with potent bass and call your insurance agent to ensure that you're covered for the rumbling that's about to occur. You won't have to strain to hear what I'm talking about. Such is the attraction of this preamp.

Versus the Reference 3

Audio Research's Reference 3 ($9995) is another line-stage preamp that some people are calling unique. While it may follow on ARC's earlier Reference designs, its completely new low-distortion topology is based on the 6H30 tube, and it has a hybrid power supply. Like The Tube, the Reference 3 is a single-box fully balanced preamp, but the similarities end there. The Reference 3 operates in a traditional manner -- no wait when switching from one input to another -- and has a much more hearty feature set, including a numerical volume readout and full-function remote control. When you think of a modern line-stage preamp, the Reference 3 is what you imagine.

The stark differences between these two preamps extend to sonics as well. The Reference 3 retains a bit of tube sweetness amidst a soundstage that is truly wall to wall. Along with these things is a handling of dynamic progression -- the ability to move from soft to loud gradually and not in electronic-induced leaps -- that sounds real and does wonderful things for music. In contrast, The Tube's exceedingly wide dynamic range shifts up and down with lightning speed, losing some sense of the music's natural ebb and flow. Its soundstage is impressive, but not as wide as the Reference 3's.

More than these things, however, is the difference in perspective. The Tube is more forward, which creates a visceral connection with the music, while the Reference 3's window on the music is decidedly mid-hall. The Tube confronts, and the Reference 3 draws in. There is, again, an obvious difference in the way that these two tube preamps handle bass, with The Tube's low frequencies sounding more crisp and physical and the Reference 3's being warmer and not quite as rhythmic.

Bottom-line time: While I would choose the easy resolution and more laid-back character of the Audio Research Reference 3, I still recognize and admire what The Tube accomplishes. I suspect that for some listeners, its clear, forceful sound will make it the obvious choice, even at its considerable price.

The Tube and you

Einstein's The Tube is an unusual preamp, and a special one, too. Whether it's "revolutionary," "evolutionary" or just plain "original," I can't think of another preamp quite like it. Its topology is inspired, but it's not just for show, creating a presentation whose essential lack of noise makes for thrilling dynamics. Its bass is crushing in its depth and impact, and its vivid up-front perspective will never cause you to strain to hear the slightest detail anywhere in the soundstage. All of this doesn't mean that The Tube is brutish; it captures and conveys the delicacy of each recording with the best of its competition.

I've reviewed a chorus line of terrific products so far in 2006, and the embarrassment of riches continues with The Tube. It's a Reviewers' Choice, and it may be your choice as well.

...Marc Mickelson
marc@soundstage.com

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