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)?