captive and hard-wired internally (one less connecting element). The review unit was provided with a three-metre long lead (ter- minated with a high-quality Furutech 240V three-pin plug) but custom lengths are avail- able to special order. The operational/mute LED flashes red at turn-on, then green when ‘good-to-go’ operational. It is flanked by a row of LEDs per input. The on/off switch is cunningly hidden underneath the unit. As per the Technical Brain philosophy, the TBC-Zero is designed for extremely wide bandwidth operation, such that it is quoted as having a response that extends from d.c. to 500kHz –3dB. Output imped- ance is a very low 47Ω single-ended and 94Ω balanced and gain is approximately 12dB. Physically the unit is quite large and measures 346×200×425mm. Weight, for a minimalist preamp, is considerable: 20kg. The monobloc amplifiers are equally sparse in terms of controls and unnecessary frills or embellishments. In fact, superficially, they’re visually little more than brick-like rectangular prisms; large ones at that. However subtle elements such as the front fascia’s full vertical twin operational light strips, the top plates’ small square air-vent cut-outs and the large windows into the internal heatsinks all make them aestheti- cally quite attractive with a Zen-like simplic- ity. Incidentally, the units are available in a greyish silver finish or, by special order (and at added cost), in hand-applied ‘Japanese lacquered’ gloss black. The bipolar monoblocs offer a single XLR balanced input and, again, their three-metre long 240V a.c. power cables are a captive arrangement that enters the chassis via the bottom plate. The bottom plate also houses the on/off switch which places the unit on stand-by while a small button on the fascia fully powers-up the amplifier. Again, Techni- cal Brain quotes an extended bandwidth, stating the response of the monobloc stretches from d.c. DC to 100kHz. Out- put power is rated at 350-watts into 8Ω, 700-watts into 4Ω and 1,400-watts into 2Ω. Again, a rather low input impedance is quoted (but one that’s obviously more than suitable in the context of the match- ing preamp) of 3.6kΩ (balanced) and 1.8kΩ (unbalanced). Gain is quoted as 29.8dB. [See laboratory test measurements for the technical nitty-gritty.] The monoblocs are a substantial lift at 65kg each—so enlist appropriate testosteroned assistance if you want to shuffle these big boys around. I n the relatively short time the Technical Brain brand has been available it has managed to create quite a stir. Inter- national reviews from some of the world’s most-read publications have raved and ranted in approbation for this Japanese über high-end specialist manufacturer. Out- pourings of even more intensity have been meted out at Technical Brain’s home base in Japan, with that country’s leading audio publication, StereoSound, awarding Techni- cal Brain with its Grand Prix. Not a bad head-first launch into the deep of the high- end, whose murky waters are, arguably, over-populated with premium amplification systems from all around the world. Which begs the question—does the world really need another ultra-expensive amplifier/preamplifier combo? Well, to address this and justify the answer, the new offering must bring to the fore a point of difference, a new or unusual feature, extraordinary sonics or, ideally, all of the above. Well, in the Technical Brain TBP-Zero EX power amplifiers and TBC-Zero pream- plifier, such a beast may indeed have been spawned. TECHNICALLY SPEAKING The TBP-Zero EX monoblocs and TBC-Zero EX preamplifier are large and elegantly simple components hand-built in Japan to exacting standards. Company founder and head of design Naoto Kurosawa has, in typical Japanese fashion, a relentless dedica- tion to account for the smallest of details, and subscribes to the ‘everything makes a difference’ school of philosophy. Kurosawa’s extensive experience in servicing top-notch electronics led to the desire to design products that were improvements in terms of reliability and functionality while sonically performing to the highest levels. It follows then, that the units under review feature top-rate construction while, in particular, the preamp’s controls function with an operational assuredness that reaffirms the expectation of reliability and longevity. The FET and bipolar transistor control unit or preamplifier has four inputs and two outputs, all with single-ended and balanced connectivity. The large front fascia sports only an input rotary knob and a volume control that, when firmly pushed in, doubles as the mute button. As further testament to Kurosawa’s dedication to simplicity and attention to detail, the mains power cord is Kurosawa’s proprietary output circuitry is patented, with Technical Brain claim- ing the monoblocs to be ‘the world’s first complete d.c. transistor amplifier with no emitter resistors.’ The proprietary current- control circuit operates without time delay. The amplifiers have massive 1.6kVA custom EI transformers of the highest quality (the core alone is said to weigh over 20kg!), no mechanical contacts such as relays and fuses, and parts are said to be painstakingly matched and positioned for optimised cir- cuitry and vibration control. When I queried the operating class of the amplifier, I was told that the amplifiers operate in Class-A mode up to an output of 3-watts, after which operation is Class-A/B. I asked Kurosawa what differentiates Technical Brain amplifiers from other high- powered amps, and his reply was, ‘the core concept of the Technical Brain amplifiers is to eliminate all the factors that distract the reproduction of music. In particular, my challenge was how precisely an amplifier can respond to the very moment a sound begins. This is when all the energy and emotion of music/musician is released at once. To reproduce this very moment re- quires absolute power (pulse-like exception- ally large current) that drives speakers accu- rately. It is emitter resisters that prevent the injection of this energy from an amplifier to speakers. In order to protect an ampli- fier from thermal runaway, emitter resisters restrain the flow of current using nega- tive feedback, while compensating for the differences in operating current between power transistors. Since the early years of transistor amplifiers, emitter resistors have been used as a necessary evil. The most important technological innovation of Tech- nical Brain is the elimination of emitter resis- tors and the development of a bias current control circuit without time delay—which I have patented in Japan—which has made possible the elimination of emitter resistors. Next, we have eliminated electrical contacts that cause a sound modulation/spread. Among a number of electric contacts found in amplifiers, the elimination of high cur- rent relays used in speaker protection and a power supply unit is a key to a better sound. It is also important to be noted that electric contacts are gradually oxidized and sulphurised over time, and as a result, contact resistance becomes non-linear. Lastly, all the Technical Brain electronics are complete d.c. amplifiers (direct current is amplified and there is no phase rotation nor group-delay). A colourless, unconstrained, stable sound comes from this coherence in design.’ Future Technical Brain products are ru- moured to be in the pipeline; an integrated amplifier rated at 100-watts, a stereo power amplifier rated at 150-watts per channel and a USB DAC. THE EAR/BRAIN RELATIONSHIP Zensati Australia, the distributor for Techni- cal Brain, delivered these amplifiers (in three massive roadcases) and provided the man- power to unpack and position these large components in my auditioning room. The preamp was fed via my reference Metro- nome T1i CD player while the monos were lashed to Wilson Sasha W/P. I auditioned the Technical Brain components over a period of about five weeks. At this stage it’s worth mentioning that the Technical Brain units were delivered along with a full loom of Zensati signal cables which were substituted into the system in the last three weeks of my audition. There were some very strong synergies at play there in terms of sound coherency and overall tonality; anyone lucky TECHNICAL BRAIN TBC-ZERO PREAMPLIFIER AND TBP-ZERO MONOBLOC POWER AMPLIFIERS Power Output into 8-ohm, 4-ohm and 2-ohm non-inductive loads at 20Hz, 1kHz and 20kHz. [TBrain] Newport Test Labs The world’s first complete d.c. transistor amplifier with no emitter resistors, according to designer Naoto Kurosawa Power Output into 8-ohm, 4-ohm and 2-ohm non-inductive loads at 20Hz, 1kHz and 20kHz. [TBrain] 86 87 ON TEST ON TEST
Transcript
captive and hard-wired internally (one less connecting element). The review unit was provided with a three-metre long lead (ter-minated with a high-quality Furutech 240V three-pin plug) but custom lengths are avail-able to special order. The operational/mute LED flashes red at turn-on, then green when ‘good-to-go’ operational. It is flanked by a row of LEDs per input. The on/off switch is cunningly hidden underneath the unit.
As per the Technical Brain philosophy, the TBC-Zero is designed for extremely wide bandwidth operation, such that it is quoted as having a response that extends from d.c. to 500kHz –3dB. Output imped-ance is a very low 47Ω single-ended and 94Ω balanced and gain is approximately 12dB. Physically the unit is quite large and measures 346×200×425mm. Weight, for a minimalist preamp, is considerable: 20kg.
The monobloc amplifiers are equally sparse in terms of controls and unnecessary frills or embellishments. In fact, superficially, they’re visually little more than brick-like rectangular prisms; large ones at that. However subtle elements such as the front fascia’s full vertical twin operational light strips, the top plates’ small square air-vent cut-outs and the large windows into the internal heatsinks all make them aestheti-cally quite attractive with a Zen-like simplic-ity. Incidentally, the units are available in a greyish silver finish or, by special order (and at added cost), in hand-applied ‘Japanese lacquered’ gloss black.
The bipolar monoblocs offer a single XLR balanced input and, again, their three-metre long 240V a.c. power cables are a captive arrangement that enters the chassis via the bottom plate. The bottom plate also houses the on/off switch which places the unit on stand-by while a small button on the fascia fully powers-up the amplifier. Again, Techni-cal Brain quotes an extended bandwidth, stating the response of the monobloc stretches from d.c. DC to 100kHz. Out-put power is rated at 350-watts into 8Ω, 700-watts into 4Ω and 1,400-watts into 2Ω. Again, a rather low input impedance is quoted (but one that’s obviously more than suitable in the context of the match-ing preamp) of 3.6kΩ (balanced) and 1.8kΩ (unbalanced). Gain is quoted as 29.8dB. [See laboratory test measurements for the technical nitty-gritty.] The monoblocs are a substantial lift at 65kg each—so enlist appropriate testosteroned assistance if you want to shuffle these big boys around.
I n the relatively short time the Technical Brain brand has been available it has managed to create quite a stir. Inter-
national reviews from some of the world’s most-read publications have raved and ranted in approbation for this Japanese über high-end specialist manufacturer. Out-pourings of even more intensity have been meted out at Technical Brain’s home base in Japan, with that country’s leading audio publication, StereoSound, awarding Techni-cal Brain with its Grand Prix. Not a bad head-first launch into the deep of the high-end, whose murky waters are, arguably, over-populated with premium amplification systems from all around the world.
Which begs the question—does the world really need another ultra-expensive amplifier/preamplifier combo? Well, to address this and justify the answer, the new offering must bring to the fore a point of difference, a new or unusual feature, extraordinary sonics or, ideally, all of the above. Well, in the Technical Brain TBP-Zero
EX power amplifiers and TBC-Zero pream-plifier, such a beast may indeed have been spawned.
Technically SpeakingThe TBP-Zero EX monoblocs and TBC-Zero EX preamplifier are large and elegantly simple components hand-built in Japan to exacting standards. Company founder and
head of design Naoto Kurosawa has, in typical Japanese fashion, a relentless dedica-tion to account for the smallest of details, and subscribes to the ‘everything makes a difference’ school of philosophy. Kurosawa’s extensive experience in servicing top-notch electronics led to the desire to design products that were improvements in terms of reliability and functionality while sonically performing to the highest levels. It follows then, that the units under review feature top-rate construction while, in particular, the preamp’s controls function with an operational assuredness that reaffirms the expectation of reliability and longevity.
The FET and bipolar transistor control unit or preamplifier has four inputs and two outputs, all with single-ended and balanced connectivity. The large front fascia sports only an input rotary knob and a volume control that, when firmly pushed in, doubles as the mute button. As further testament to Kurosawa’s dedication to simplicity and attention to detail, the mains power cord is
Kurosawa’s proprietary output circuitry is patented, with Technical Brain claim-ing the monoblocs to be ‘the world’s first complete d.c. transistor amplifier with no emitter resistors.’ The proprietary current-control circuit operates without time delay. The amplifiers have massive 1.6kVA custom EI transformers of the highest quality (the core alone is said to weigh over 20kg!), no mechanical contacts such as relays and
fuses, and parts are said to be painstakingly matched and positioned for optimised cir-cuitry and vibration control. When I queried the operating class of the amplifier, I was told that the amplifiers operate in Class-A mode up to an output of 3-watts, after which operation is Class-A/B.
I asked Kurosawa what differentiates Technical Brain amplifiers from other high-powered amps, and his reply was, ‘the core concept of the Technical Brain amplifiers is to eliminate all the factors that distract the reproduction of music. In particular, my challenge was how precisely an amplifier can respond to the very moment a sound begins. This is when all the energy and emotion of music/musician is released at once. To reproduce this very moment re-quires absolute power (pulse-like exception-
ally large current) that drives speakers accu-rately. It is emitter resisters that prevent the injection of this energy from an amplifier to speakers. In order to protect an ampli-fier from thermal runaway, emitter resisters restrain the flow of current using nega-tive feedback, while compensating for the differences in operating current between power transistors. Since the early years of transistor amplifiers, emitter resistors have been used as a necessary evil. The most important technological innovation of Tech-nical Brain is the elimination of emitter resis-tors and the development of a bias current control circuit without time delay—which I have patented in Japan—which has made possible the elimination of emitter resistors. Next, we have eliminated electrical contacts that cause a sound modulation/spread. Among a number of electric contacts found in amplifiers, the elimination of high cur-rent relays used in speaker protection and a power supply unit is a key to a better sound. It is also important to be noted that electric contacts are gradually oxidized and sulphurised over time, and as a result, contact resistance becomes non-linear. Lastly, all the Technical Brain electronics are complete d.c. amplifiers (direct current is amplified and there is no phase rotation nor group-delay). A colourless, unconstrained, stable sound comes from this coherence in design.’
Future Technical Brain products are ru-moured to be in the pipeline; an integrated amplifier rated at 100-watts, a stereo power amplifier rated at 150-watts per channel and a USB DAC.
The ear/Brain relaTionShipZensati Australia, the distributor for Techni-cal Brain, delivered these amplifiers (in three massive roadcases) and provided the man-power to unpack and position these large components in my auditioning room. The preamp was fed via my reference Metro-nome T1i CD player while the monos were lashed to Wilson Sasha W/P. I auditioned the Technical Brain components over a period of about five weeks. At this stage it’s worth mentioning that the Technical Brain units were delivered along with a full loom of Zensati signal cables which were substituted into the system in the last three weeks of my audition. There were some very strong synergies at play there in terms of sound coherency and overall tonality; anyone lucky
Technical Brain TBc-Zero PreamPlifier andTBP-Zero monoBloc Power amPlifiers
Power Output into 8-ohm, 4-ohm and 2-ohm non-inductive loads at 20Hz, 1kHz and 20kHz. [TBrain]
New
port
Tes
t Lab
s
The world’s first complete d.c. transistor amplifier with no emitter resistors, according to designer Naoto Kurosawa
Power Output into 8-ohm, 4-ohm and 2-ohm non-inductive loads at 20Hz, 1kHz and 20kHz. [TBrain]
86 87
on test On TEST
enough to be looking at the Technical Brain amplifiers should go the extra yard, do themselves a favour, and hear them with a full Zensati cable loom.
The Technical Brain electronics replaced the long-term preamp of choice over at the Kramer’s—the Supratek Sauvignon (with mods)—and the extraordinary Cymer Audio Southern Cross SET monos. These two valve reference components have a truly sublime ability to reproduce timbral textures and tonal accuracy. These traits, in my experi-ence, have been the sole domain of SETs in particular, with solid-state amplifiers not quite managing the same level of tonality. Well, to me, the Technical Brains are the very first.
If I was to describe the overall sonic signature of these extraordinary products I’d have to use the terms ‘midrange beauty’, ‘unrestricted dynamic range’, ‘lightning-fast transient attack’ and ‘solid and tuneful bass’. One of my favourite orchestral pieces is Tchaikovsky’s Violin Concerto as master-fully played by Boris Belkin on Decca. It’s a vastly-soundstaged recording that has been skilfully captured to allow Belkin’s dexterity and subtlety to shine through. The Technical Brains’ handling of subtle inflections and minutiae in Belkin’s technique is revelatory. There’s an inherent simultaneous ability to separate the principal musical information and the subtleties below that primary sur-face, in a way that translates into a musical event. The orchestra spans across the room beyond the speakers’ boundaries and the Technical Brains’ reproduction of depth stretches beyond the back wall.
Harmonically complex as a well-recorded piano can be—such as Tori Amos’ hammer-ing of the Bösendorfer she used on Boys for Pele—the Technical Brain handled it with sharp attack while deli-cately carrying the notes’ trailing decays—without perceivable foreshortening—and playing the low notes with weight, depth, and detail. And although the concept of ‘blackness’ between the notes can be somewhat ethe-real to some (until experienced in such a profound manifestation), in practice, the Technical Brain electronics were the archetype of this phenomenon. There’s a sense of space and quietude between the density of the instrumental strands that allows for a more realistic musical flow, and then,
somehow, an intense emotional connect.Almost as what may seem as a contra-
diction to the comments on tonal beauty, the Technical Brain components are aston-ishingly transparent. The preamp especially is not unlike the proverbial ‘wire with gain’ and its transparency is preserved by the neutrality of the monos. What may sound contradictory is that that beautiful tonal-ity is sometimes tied-in with an addition or deviation from neutrality, a sonic signature that can sometimes be syrupy, softer and, at worst, over-warm. In this case, the precision of the Technical Brain components allows the tonal cues to be communicated uncol-oured and unadulterated. Of course, at the end of the day, the speakers need to be chosen wisely, and be of appropriate quality, to capitalise on the Technical Brains’ tonal, transient and dynamic accuracy.
And as much as the Technical Brains’ own beauty and finesse, they can sure slam it when it counts. Speakers permit-ting, the dynamic power and punch slung at the listener when playing Rage Against the Machine’s seminal self-titled release, for example, can be devastating. Massive swings in dynamics apply across the board frequency-wise, but truly, the bass control, harmonic detail, slam, depth and transient snap on offer here are unmatched in my experience. And you know a component is stellar (and this happens rarely) when an involuntary smile spreads across your dumbfounded face and you find yourself toe-tapping without even realising it.
concluSionThe Technical Brain TBC-Zero EX preampli-fier and TBP-Zero EX monoblocs are truly remarkable. Sonically, they are superbly transparent, blindingly fast in transient
TECHNICAL BRAIN PREAmPLIfIER AND mONOBLOC POWER AmPLIfIERs
Brand: Technical Brainmodel: TBP-Zero EX/TBC-ZeroCategory: Power Amp/Pre-amplifierRRP: $79,000 (pair)/$46,000Warranty: Three YearsDistributor: Zensati AustraliaT: (04) 1300 7440E: [email protected]: www.zensatiaustralia.com
State-of-the-art soundSuperb build and engineering
Captive power cablesPrice
attack, utterly controlling over the mated speakers, and possess the tonal and timbral magic of the very best Single Ended Triodes. There’s no disputing that the Technical Brain products are expensive. But do they offer value? That’s a relative call. The idea of value can be represented by a formula, or ratio, made-up of relationships between an individual’s depth of pocket, apprecia-tion of brand cachet, sonic and engineering satisfaction and overall appeasement of ex-pectations. Bearing those elements in mind, and after many weeks of absolute sonic delight, I can say that, as far as solid-state amplification is concerned, the Technical Brain preamplifier and, in particular the monoblocs, are game-changers. Naoto Kurosawa is on to something rather special… Edgar Kramer
TeST reSulTS
This Technical Brain combo delivered excellent performance on the test bench at Newport Test Labs in all
tests. However in one area—power out-put—the TBP-Zero power amplifier failed to meet any of the power output ratings claimed for it, which led me to wonder whether Technical Brain was using a method different to those usually employed. Newport Test Labs measured the maximum power output of the TBP-Zero V.2 (with a test frequency of 1kHz) as being 300-watts
continuous into 8Ω and 522-watts continu-ous into 4Ω. And although Technical Brain quotes a power output into 2Ω (the claim being for 1,400-watts), there is a protection circuit inside the Technical Brain that trig-gers at an output level of 450-watts when driving 2Ω loads which means that under Australian standards, the maximum output power of the Technical Brain into 2Ω would have to be stated as being 450-watts.
However, despite the TBP-Zero falling 50-watts short of its claimed power into 8Ω, and 178-watts short into 4Ω loads, the
actual decibel differences are quite small: just a 0.6dB shortfall into 8Ω and 1.2dB at 4Ω. In other words, the human ear would not be able to detect any difference in out-put volume when driving 8Ω loads, and the difference in volume between 522-watts and 700-watts would be just ‘barely percep-tible’ under ideal listening conditions.
The measured frequency responses, on the other hand, far exceeded Technical Brain’s claims for them. Newport Test Labs tested the overall response through both the TBC-Zero EX preamp and the TBP-Zero v.2 power amplifier and, as you can see from the tabulated figures, the responses stretched from d.c. to 290kHz –1dB and from d.c. to 540kHz –3dB. Or, if you prefer, 0–290kHz ±0.5dB and 0–540kHz ±1.5dB. The frequency response across the audio band is shown in Graph 7. The response is so flat that Newport Test Labs has had to use a hugely inflated vertical scaling in order
to show variations, so the top of the graph is +0.4dB and the bottom is –0.4dB. One trace shows the response into a standard, non-inductive laboratory-grade resistor, the other trace shows it into a load that simulates the one that would be presented to the amplifier by a typical two-way loudspeaker system. The two traces are almost identical—which, if memory serves me correctly is the first time any amplifier has performed perfectly in this test. You can see the responses ‘roll off’ below 10Hz, but are only 0.16dB down at 5Hz. At the upper end, the responses start rolling off at 10kHz, but are just 0.08dB down at 20kHz and 0.16dB down at 40kHz. This puts the ‘audio-band’ response at 20Hz to 20kHz ±0.04dB.
Total harmonic distortion was very low, as you can see from the graphs. It appears that an errant signal from a near-by computer screen has infiltrated the measurements, so
88 89
on test TECHNICAL BRAIN PREAMPLIFIER AnD MOnOBLOC POWER AMPLIFIERS
Graph 8: Intermodulation distortion (CCIF-IMD) using test signals at 19kHz and 20kHz, referenced to a 1 watt output (at 0dB) across an 8-ohm non-inductive load. [Technical Brain TBP-Zero Power Amplifier]
Newport Test Labs
10.00 Hz 100.00 1000.00 10000.00 40000.00
-0.40
-0.32
-0.24
-0.16
-0.08
0.00
0.08
0.16
0.24
0.32
0.40dBr
Graph 7: Frequency response of line input referenced to a 1 watt output (at 0dB) across an 8-ohm non-inductive load (Black Trace) and across a combination resistive/inductive/capacitive load representative of a typical two-way loudspeaker system (Red Trace). [Technical Brain TBP-Zero Power Amplifier]
Graph 6: Total harmonic distortion (THD) at 1kHz referenced to 240-wattsacross a 4-ohm non-inductive load. [Technical Brain TBP-Zero Power Amplifier]
Newport Test Labs
The two traces are almost identical—which ... is the first time any amplifier has performed perfectly in this test
LAB REPORT
you should ignore the ‘spike’ in the traces that appears just below 16kHz on most of the graphs. At one watt into 8Ω, there are no harmonically-related distortion components visible above the noise floor. That said, the noise floor is sitting at around –110dB, which means that even if there are distortion components hidden in the noise, they contribute less than 0.0003% and would thus be completely inaudible. When driving
4Ω loads (Graph 2) a single third-order harmonic component becomes visible, and sits at –98dB, or 0.001% THD.
Graphs 3 and 4 show the Technical Brain’s distortion when delivering 100-watts into 8Ω (Graph 3) and 4Ω loads (Graph 4). You can see that the noise floor has dropped to around –125dB (since it’s now referenced to 100-watts, at the top of the graph). Harmonically-related distortion components are visible in both graphs, but all except one are more than 100dB down, and so contribute less than 0.001% THD to the overall figure. (The exception is the third harmonic in the 4Ω graph, which is at a level of –94dB, and so contributes 0.0019%.)
Newport Test Labs ran a spectrum analysis on the Technical Brain’s output when the amplifier combo was delivering 285-watts rather than the maximum output of 300-watts, because at 300-watts the amplifier was being driven into clipping. The picture at 285-watts (Graph 5) is very good. The third harmonic distortion component dominates at –77dB (0.014%), followed by the fifth harmonic at –85dB (0.005). All other harmonic distortion components are below –100dB (0.001%) except the second harmonic, which is very slightly above that level. The distortion ‘signature’ is much the same into 4Ω loads, as you can see from Graph 6.
Perhaps the most interesting of all the results was that for CCIF intermodulation distortion, which uses two very high-fre-quency test signals (at 19kHz and 20kHz).
You can see these signals towards the right-hand-side of the graph. Normally, I would expect to see sideband intermodu-lation components either side of these two signals, plus a regenerated difference signal down at 1kHz. As you can see, the output of the Technical Brain is absolutely clean—there’s not a skerrick of intermodu-lation distortion to be seen. Again, I think
this is the first time I’ve ever seen such an outstandingly good result from an amplifier.
I was intrigued that Technical Brain doesn’t quote signal-to-noise ratios, but the results gave me an idea why they don’t. Al-though the results measured by the lab are good (and remember that the results shown were obtained with both the TBC-Zero and TBP-Zero in circuit, so the signal was going through both pre-amplifier and power
Technical Brain TBC-Zero Ex Pre & TBP-Zero ver.2 Power AmpTest Measured Result Units/Comment
Frequency Response @ 1 watt o/p d.c. – 290kHz –1dB
Frequency Response @ 1 watt o/p d.c. – 540kHz –3dB
THD+N 0.01% / 0.006% @ 1-watt / @ rated output
Signal-to-Noise (unwghted/wghted) 71dB / 78dB dB referred to 1-watt output
Signal-to-Noise (unwghted/wghted) 90dB / 97dB dB referred to 100-watts output
Signal-to-Noise (unwghted/wghted) 96dB / 102dB dB referred to 300-watts output
Note: Figures in the dBW column represent output level in decibels referred to one watt output.
* Internal protection circuit tripped at this power output level when driving 2Ω load (continuous).
amplifiers) they’re not great. Referenced to 1-watt, the lab measured signal-to-noise at 71dB unweighted and 78dB weighted. Referenced to 100-watts, these figures improved to 90dB (unweighted) and 97dB (weighted). It wasn’t until the amplifier was operating at its maximum measured power that the weighted figure crept over the magic ‘100dB’ mark, to 102dB, with the unweighted figure still dragging behind at 96dB.
It’s worth taking some time to pore over the oscillograms showing the Technical Brain’s performance with square waves, be-cause they are simply magnificent examples
of what it’s possible to achieve. Look at that 100Hz trace! It is the best I have ever seen from any amplifier… in fact it is perfect, so while in the future another amplifier might be able to match this level of performance, it won’t be able to exceed it. The same is true for the 1kHz waveform pictured: once again, it is perfect. It just doesn’t get better than this! The 10kHz wave is not quite perfect, but it’s an excel-lent result with an ultra-fast rise time and barely any rounding. Performance into a capacitative load is also excel-lent. There is a small overshoot and some ringing visible on the waveform, but the ringing is quickly damped, so
the amplifier would be unconditionally stable into any loudspeaker load.
As you’d imagine, the Technical Brain combo consumes an enormous amount of mains power, ranging from a fairly high 27-watts in standby and rising to 176-watts when the amplifiers are
‘on’ but not yet operating. Once they are operating, they consume between 378 and 1,256 watts. Still, I guess that anyone who can afford the Technical Brains obviously won’t be worried about something as trivial as their quarterly electricity bills!
Steve Holding
Again, I think this is the first time I’ve ever seen such an outstandingly good result from an amplifier
90 91
LAB REPORT TECHNICAL BRAIN PREAMPLIFIER AnD MOnOBLOC POWER AMPLIFIERS LAB REPORT
We test this hugely powerful subwoofer!
MK SOUND SB1250
REVIEWED
SHOW REPORT BRISTOL 2012Jul/Aug 2012 $7.95 AVHUB.COM.AU
THE ITALIAN JOBSingle-ended Class-A valve design improved by user bias calibration
Manley ChinookPhono Preamp
Usher Audio S-520Bookshelf Speakers
Unison Research S6Integrated Amplifi er
D’Agostino MomentumMonobloc Power Amps
B.M.C. BCCD1 & DAC1 CD Player & DAC/Pre
MK Sound SB1250Subwoofer
HF July12_001 Cover_R.indd 1 15/06/2012 11:33:26 AM
WE’VE ALL GONE DIGITAL SHOW REPORT
THE ITALIAN JOBTHE ITALIAN JOBSinglSingle-e-ended Clasended Clasended Clasimproved by user bias calibration
We test this hugely powerful subwoofer!
MK SOUND SB1250
SHOW REPORT BRISTOL 2012Jul/Aug 2012 $7.95 AVHUB.COM.AU
THE ITALIAN JOBTHE ITALIAN JOBTHE ITALIAN JOBTHE ITALIAN JOBTHE ITALIAN JOBTHE ITALIAN JOBTHE ITALIAN JOBTHE ITALIAN JOBTHE ITALIAN JOBended Clasended Clasended Clasended Clasended Classs-A valve design A valve design A valve design A valve design A valve design
improved by user bias calibrationimproved by user bias calibration
Aug/Sep 2012
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