Begin typing your search above and press return to search. Press Esc to cancel.

Technical Brain Revisited

The moment I first heard Technical Brain solid-state electronics three-and-a-half years ago at Naoto Kurosawa’s shop in Kawagoe, Japan, I was bowled over by their sound. Listening to music that I had brought with me from the U.S.—and thought I knew by heart—played back through Kursoawa’s Technical Brain TBP-Zero v2 monoblock power amplifiers, TBC-Zero v2 linestage, TEQ-Zero v2 phonostage, TMC-Zero step-up transformer, and Apogee Duettas (never the easiest loudspeakers to drive), I realized instantly that what I thought I knew by heart I didn’t really know at all, by heart or otherwise. Here, on every single CD and LP, was a wealth of detail—musical, performance, and engineering—that I’d simply never heard before, presented with unprecedented transparency, transient speed, image focus, and soundstage breadth and depth. The net effect was a realism that simply towered above what the other solid-state gear I’d heard up to that time was capable of.

Oh, if I had been in a nitpicking frame of mind there were things about the TB electronics that might’ve given me pause. Their overall sound, like that of much Japanese transistor gear, was “top-down” rather than “bottom-up” (to make use, yet again, of Raidho chief engineer Michael Børresen’s indispensable distinction).

Sonically, the TB gear was biased toward the midrange and the treble, giving it a lighter, somewhat brighter and livelier tonal balance (very much like that of vintage ARC gear). Though its grip, transient speed, and resolution in the bass were excellent, it was also a little thinner-than-life in color and body through the mid-to-upper bass and the power range, and a little brighter-than-life in the upper mids. Still and all, at that time I hadn’t heard anything that came close to rivaling it in sheer speed and resolution—or in in-the-room-with-you realism.

Well…times have changed and Technical Brain no longer stands alone at the pinnacle of high-end solid-state electronics. It’s not that the sound of TB has gotten worse; it’s that the competition has gotten so much better. Between Constellation’s marvelous Performance and Reference Series electronics and Soulution’s 500 Series (soon to be reviewed by me) and 700 Series products—to name just a few of many heavyweight-title contenders—the resolution and transient speed gap, once the size of the Grand Canyon, has been narrowed to the width of a bike path. Plus both the Constellation and Soulution products lay claim to a more neutral-to-“bottom-up” tonal balance, which is to say that they are inherently somewhat richer, more fleshed-out (particularly in the bass and power range), and more beautiful- sounding than the original TB offerings I heard in Japan.

 Happily, the sound of the latest Technical Brain electronics—now in Kurosawa’s TB- Zero/EX versions (not to be confused with the short-lived, more electrically reliable, but, IMO, inferior-sounding “Import” versions, substantially modified and briefly marketed here in the U.S.)—have also changed with the times, and for the better. (There are reasons why this little company continues to win more Grand Prix Awards from the Japanese magazine Stereo Sound than any of its competitors.)


While I can’t honestly say that these new TB-Zero/EX electronics are more transparent than the v2 versions (actually I’m not sure this would be possible), they are closer to neutral in balance—not exactly darker or more bottom-up-sounding, but no longer slightly lean or markedly top- down-sounding. Lifelike weight and color have been added to the midrange, the lower midrange, and the bass octaves, and so has dynamic oomph. Though the TBP-Zero/EX isn’t the equal of the Soulution 500 in sheer mid-to-upper-bass and power-range slam, it does have considerably more midbass slam than it had previously, coupled, as noted, with inherently richer, more saturated, more realistic color and body from the power range right through the upper mids. And, of course, it still has that incredible resolution and transient speed, which keeps it just a step ahead (in these regards) of even its finest and fiercest competition.

Let me talk about that transient speed for a moment—and about what it and the TB- Zero/EX’s newfound richness of timbre can buy you on the best recordings. Once again, I’m going to point to George Crumb’s Four Nocturnes for Violin and Piano on the great Mainstream/Time LP, simply because this piece (and everything else on this record) is capable of sounding “fool-you” realistic when it is reproduced by a great speaker, great electronics, and a great analog source component.

As I noted in my DaVinciAudio Labs’ Master’s Reference Virtu tonearm review [Issue 230], the second Nocturne is played (by violinist Paul Zukofsky) almost entirely pizzicato. There are passages where the piano is also played pizzicato, with the pianist Gilbert Kalish plucking the notes by hand rather than by key in “string piano” fashion. Glissandos and pizzicato glissandos are also sounded by both instruments, which, as I noted in the DaVinci review, give this eerie night music a swooping, sharply punctuated this hard transient with an immediacy and intensity that not only thrills the ear but that also sounds uncannily and unmistakably like the real thing. sound-quality reminiscent of that supreme masterpiece of night music, Bartok’s Third String Quartet.

Though violin pizzicatos are always short and percussive, they aren’t always as “strong” as they sound in the Crumb piece. The sharpness of their report is due, in some part, to the unusually close miking of both instruments (and to the mikes themselves); in larger part, it is owed to the way the pizzicatos are being played. These are so-called “Bartók pizzicatos,” in which the string isn’t plucked lightly and/or obliquely but plucked hard vertically, so that it rebounds off the fingerboard of the instrument with a loud snap. The Technical Brain TBP/TBC/TEQ/TMC reproduces sound-quality reminiscent of that supreme masterpiece of night music, Bartok’s Third String Quartet.

As I noted in my ARC review [Issue 229], electronics always play their own little tricks with the timing of notes, slightly slowing down their durations so they lose a bit of initial transient energy but gain density of tone and decay, or slightly speeding them up so that the transient part of the harmonic/dynamic envelope gets accentuated (and impact and goosebumps are elevated) while the full utterance of tone and decay are somewhat scanted. At one point in time, I would’ve said that the Technical Brain gear was closer to the latter model than to the former. Not so, anymore.


You see it isn’t just the sheer excitement of hearing a series of pizzicato transients reproduced as they sound in life, with their energy, timing, and impact precisely intact, that makes the TB gear so extraordinarily realistic (given a great loudspeaker). Pizzicatos also have timbre, though that timbre doesn’t comprise the harmonic series—the roughly even multiples of the fundamental that we hear with a bowed note. The overtones of a plucked note are inharmonic (like the “colors” of cymbals or chimes)— they are spectral partials and their intensity and duration depend on the elasticity, length, and tension of the string being plucked. On violin strings, they typically do not last long, but they give the transient a characteristic color (and sometimes a touch of warmth). The Technical Brain electronics don’t just accurately reproduce the transient portion of a pizzicato with lifelike speed and intensity; they also reproduce the short burst of color that is tightly associated with the “pluck” with equal realism. They get the whole dynamic/harmonic sequence right.

It may be obvious, but electronics that can do this with something as complex (albeit short-lived) as a pizzicato can also do this with the longer durations of more conventionally sounded notes, such as those of the two pianos and orchestra of Poulenc’s Concerto for Two Pianos [Decca], where, as opposed to the spare simplicity of the Crumb piece, a great deal is going on at once—in a multitude of timbres and at many levels of intensity and pitch. No, the TB gear doesn’t make the entirety of this piece sound as realistic as the violin and piano do on the Mainstream LP, but it certainly makes the vast majority of who’s doing what and when and how and for how long as clear as (if not clearer than) any other electronics I’ve used. And it does this with great timbral beauty (because this is a gorgeous recording), power (because this is a powerful recording), ambience (because this is a highly ambient recording), and simply extraordinary detail.

For an example of this last virtue, on the Poulenc piece other amps and preamps can reproduce the slight whistling sound of the flutist, doubling the piano at the right side of the stage toward the close of the first movement, as he blows into his mouthpiece, but none that I’ve heard can do it with such fine resolution and perfect timing that you can almost visualize the instrument and instrumentalist. Through the TB, the sound is exactly like someone blowing into the mouth of a bottle (which is pretty much how a flute works); with other gear it is simply a whistling noise in the background—more like the creak of a chair or the rustle of pages of music being turned, a sound that is not as intimately or organically connected to the playing of the flute as it is through the TB gear.

For a third and in some ways even subtler instance, consider the sound of Lou Reed’s voice on “White Heat, White Light” from Rock ’n’ Roll Animal [RCA]. I’ve been listening to this lively album since I was kid—and am now listening to a Danish reissue I picked up in Aarhus while visiting Raidho. While the DaVinciAudio Labs Virtu tonearm (with Clearaudio Goldfinger Statement cartridge) plays a large role in this as I have acknowledged—as do the Raidho C 4.1 and, alternately, the Estelon X Diamond loudspeakers—Reed’s voice simply sounds more youthful and more vigorous through the TB electronics suite (and, to a larger extent, only through the TB electronics suite) than I’m used to hearing it sound. Here, almost magically, Reed is once again a thirty-year-old kid, fired by the excitement of the crowd and the energy of his great pickup band (and the dynamic life of the TB electronics). His shouts on this number and on “Lady Day” are genuinely joyous, near-voice-cracking shrieks; his delivery more supple, articulate, engaged ; his voice less hooded, world-weary, and slumbrous. Electronics (and sources and speakers) that can actually make Lou Reed sound thirty again rather than generic Lou Reed really are functioning, in that most exhausted of audio clichés, as time machines.

How Technical Brain manages this lifelike speed and resolution (and thereby clarifies the “timing” of notes and the way they are being played or sung) has to do with Kurosawa’s innovative engineering. As I noted two years ago, in my review of the v2 versions of these products, the design elements that all Kurosawa’s products share—amp, preamp, and phonostage—are ultra- wide bandwidths (all TB components are zero-global- feedback, non-servo, DC-coupled designs); fully balanced topologies with no mechanical contacts such as relays and line fuses and extraneous pots (such as a balance control); the meticulous arrangement of wires and components to ensure the shortest signal paths and the highest shielding from vibration; massive, low-flux-density, flat-coil, hand-wound, EI-core power transformers (no toroidal transformers here); and, perhaps most interestingly and certainly most unusually, no emitter resistors.


This last is genuinely novel. As I understand it, the values of the emitter resistors affect the quiescent current running through the transistors. Since the amount of bias is determined by the voltage across the base and the emitter, if you change the emitter-resistor value, the base- emitter voltage changes with it.

It is Kurosawa’s contention that these resistors cannot be matched closely enough in value, tolerance, and temperature-sensitivity to prevent thermal drift under operating conditions. When each of the emitter resistors starts drifting to slightly different degrees, bias current to the individual power transistors slightly drifts with them and the output transistors stop functioning in identical phase. This results in small shifts in time and, subsequently, transient and frequency response, which quite literally get “amplified” by the output circuit. By meticulously selecting and matching output transistors and employing what he calls “duplex temperature compensation,” Kurosawa is able to forgo the use of emitter resistors—and, so he claims, to eliminate these emitter- resistor issues.

All of this may go right over your head (as it mostly does mine), but the sonic results of Kurosawa’s “emitter-resistor-less” circuitry won’t. With the right sources his products really are precisely what Technical Brain’s motto says they are: “Exceptionally high in transparency, exceptionally low in coloration.” Why? Because as I wrote two years ago (and just said again using different examples): “With first-rate sources, they come closer than other amps or preamps, solid-state or tube, to delivering the durations of the transient phase, the steady-state tone phase, and the decay phase of the dynamic/harmonic envelope as they are typically heard in life—without etching transients and scanting harmonics and decays, or exaggerating harmonics and decays and obscuring transients and fundamentals.” And now, because of their less “top-down” tonal balance and greater energy and richer tone color in the power range and bottom octaves, they sound realistic over a wider gamut of music.

What are the downsides of Technical Brain’s EX electronics?

First and foremost, TB’s history in the U.S. market does not inspire consumer (or reviewer) confidence. Twice before TB gear has been imported into this country by third parties, and twice before those deals have fallen apart (both times with a great deal of acrimony and finger-pointing). Although I’d like to say with confidence that this third time—importation via RATOC Systems—is the charm, I can’t. I can only hope that this will be the case. (The very fact that I’m sticking my stupid neck on the chopping block, yet again, for this benighted company should tell you one or both of two things: First, I truly love and admire the sound of Naoto Kurosawa’s Technical Brain electronics, and, second, I obviously don’t learn much from experience.)

Technical Brain’s history in the U.S. import market brings me to the second downside of its products: their price. Used to be that TB was a relative bargain in the ultra-high-end marketplace—like Constellation’s Performers or Soulution’s new 500 Series. Nowadays, that isn’t the case. The new EX gear is almost double the price of the v2 gear. Granted, it is across- the-board improved (and it was friggin’ great to begin with). For the sake of argument, let’s even grant that it may still be the highest-resolution, highest-speed solid-state electronics money can buy—and high among the (if not “the”) most lifelike. Are the $90,000 TBP-Zero/EX monoblocks roughly thirty-five- thousand dollars better than Constellation Centaur monoblocks or Soulution 501 monoblocks? Is the $58,000 TBC-Zero/EX thirty-thousand dollars better than a Constellation Virgo or a Soulution 520 (which, BTW, comes with a superb phonostage built-in)?


Even if the answer to these questions is “Yes” (and I’m not saying that it is), what about the third downside of Technical Brain’s products: the notorious unreliability of its amplifiers? Here, at least, I can say something positive with certainty. The TBP-Zero/EX amps, earlier versions of which had serious problems with U.S. current (which could trigger the failure of an FET in the power supply that necessitated the amp’s return to Japan for repair), no longer have any problem with our grid. I’ve been using the TBP-Zero/EX monoblocks for six months and there have been no failures, where, in the past, I was lucky to get through six days (or six hours) without one of the amps going south.

Finally, there is the more subjective question of tonal balance. Even though the TB EX gear is now richer in color and higher in impact in the midbass and power range (I would put it roughly on a par with the Constellation Performers/References), it is, as I noted previously, not the equal of the Soulution 501s in these areas, but then nothing is (not even Soulution’s own $130k 700 monoblocks). The 501s’ switch-mode power supplies apparently give them a leg up on every competitor in this area (so if you’re into midbass/power-range “slam,” this is certainly an amplifier you will want to give a very long listen to). But, as great as the Soulution 501 is in the midbass and power range, I don’t think it out-wallops the TBP-Zero/EX in the bottom-most octaves (20Hz–40Hz). Just put on something with really deep-reaching and powerful low bass, like Dead Can Dance’s Into The Labyrinth [MoFi]. The TB electronics go “through the floor” and shiver the walls on those deep synth notes as well as, if not better than, the 501, the 700, the Centaur, or the Altair—another substantial improvement over previous-generation TB electronics.

So what is the bottom line here?

It’s both simple—and not. I love the sound of Technical Brain’s new EX electronics. For the music I listen to, the things I listen for, the speakers I listen with, the room I listen in, and the levels I listen at, they come close to being ideal. All of these EX components—amplifiers, linestage, and phonostage—are improved over previous iterations; all of them are fuller and more lifelike in tone color (though still quite neutral) top-to-bottom; all of them are less lean and mean in the midbass and power ranges and considerably less bright in the upper mids (though still a little brighter than some of their competition); all of them are capable of nearly-unmatched speed, resolution, transparency-to-sources, and (sources permitting) a high degree of realism. All of them are unquestionably reference-grade.

However… it is easy for me to say this because I don’t have to buy them. You do. Unfortunately, as I’ve detailed, the history of this Japanese company (at least, in the U.S.) is such that I simply don’t feel comfortable recommending that you purchase its products without long auditions and careful cross-comparisons, a warranty that protects you if something goes wrong (that isn’t your fault), and a guarantee that, no matter what happens between TB and its new U.S. business partner, you will not have to pay shipping or repair costs for warranted repairs within a reasonable period of time.

TB gear has always been great—one of the true pinnacles of latter-day high-end-audio design. Now, it’s even better. (Then again, so is the competition.) It was never the sound of these components that was the problem; it was the business side. So, even though I now rank the TBP-Zero/EX, TBC-Zero/ EX, TEQ-Zero/EX, and TMC-Zero high among my ultra- high-end solid-state reference electronics, and even though the company’s relationship with RATOC Systems seems to be much stronger and more convivial than its past relationships with U.S. distributors, it would be irresponsible not to close with a “Caveat emptor.” It pains me to say it, but…buyer beware (though, let me quickly add, buyer by all means listen).



Type: Solid-state monoblock amplifier
Rated output power: 350W, 8 ohms; 700W, 4 ohms; 1400W, 2 ohms
Frequency response: DC to 750kHz (+0, –3dB at 1W)
Input: XLR
Input impedance: 3.6k Ohms (balanced)
Input sensitivity: 1.76V RMS
Gain: 29.8dB
Damping factor: 1500
Distortion: 0.02% max./8 ohms at rated power from 20Hz–20kHz
Protection circuit: DC detector
Dimensions: 13.62″ x 9.84″ x 23.62″
Weight: 143.3 lbs. (each)
Price: $90,000/pair


Type: Solid-state linestage preamplifier
Maximum output power: 10V RMS
Frequency response: DC to 990kHz (-3dB)
Input terminal: Four XLR (balanced); adapted XLR to RCA
Input impedance: 7.2k–17.2k Ohms (balanced); 3.6k–13.6k Ohms (unbalanced)
Gain: 12dB
Distortion: 0.02% max./20Hz–20kHz at 5V RMS output
Dimensions: 13.62″ x 7.87″ x 16.73″
Weight: 44.1 lbs.
Price: $58,000


Type: Solid-state phonostage preamplifier
Circuitry: Fully balanced DC with no feedback
Inputs: Four XLR (balanced); four adapted XLR to RCA
Input impedance: 54k Ohms (balanced) 27k ohms (unbalanced)
Output impedance: 94 ohms (balanced); 47 ohms (unbalanced)
Gain: 40dB at 1kHz
Dimensions: 13.62″ x 7.87″ x 16.73″
Weight: 44.1 lbs.
Price: $58,000


Type: Step-Up Transformer
Gain: 30dB
Price: $10,500

RATOC Systems (U.S. Distributor)
2000 Wyatt Drive, Suite 10
Santa Clara, CA 95054
(408) 986-9040

JV’s Reference System

Loudspeakers: Raidho C 4.1, Raidho C1.1, Estelon X Diamond, MartinLogan CLX , Magnepan 1.7, Magnepan 3.7, Magnepan 20.7
Linestage preamps: Constellation Virgo, Audio Research Reference 5SE, Technical Brain TBC -Zero EX
Phonostage preamps: Audio Research Corporation Reference Phono 2SE, Technical Brain TEQ -Zero EX/TMC-Zero
Power amplifiers: Constellation Centaur, Audio Research Reference 250, Lamm ML2.2, Soulution 501, Carver Black Beauty 305, Technical Brain TBP-Zero EX
Analog source: Walker Audio Proscenium Black Diamond Mk II record player, AMG Viella 12, Da Vinci AAS Gabriel Mk II turntable with DaVinci Master’s Reference Virtu tonearm, Acoustic Signature Ascona with Kuzma 4P tonearm
Phono cartridges: Clearaudio Goldfinger Statement, Ortofon MC A90, Ortofon MC Anna, Benz LP S-MR,
Digital source: Berkeley Alpha DAC 2
Cable and interconnect: Synergistic Research Galileo, Crystal Cable Absolute Dream
Power Cords: Synergistic Research Tesla, Shunyata King Cobra, Crystal Cable Absolute Dream
Power Conditioner: Synergistics Research Galileo, Technical Brain
Accessories: Synergistic ART system, Shakti Hallographs (6), A/V Room Services Metu panels and traps, ASC Tube Traps, Critical Mass MAXXU M equipment and amp stands, Symposium Isis and Ultra equipment platforms, Symposium Rollerblocks and Fat Padz, Walker Prologue Reference equipment and amp stands, Walker Valid Points and Resonance Control discs, Clearaudio Double Matrix SE record cleaner, HiFi-Tuning silver/gold fuses

Read Next From Review

See all

T+A Electroakustik Solitaire P Headphones

T+A’s electronic offerings should be well known to most audiophiles […]


2020 Product of the Year Awards | High-End Loudspeaker of the Year

Yamaha NS-5000  $15,000 An effort of 19 engineers and 8 […]


2020 Product of the Year Awards | Solid-State Power Amplifiers

Rogue Audio Dragon  $3995  Boasting 300Wpc into 8 ohms (500Wpc […]


VooDoo Stradivarius Amati Edition Interconnects

VooDoo Cable is an Oakland, California, cable and accessories manufacturer. […]

Sign Up To Our Newsletter