Yamaha B-6

April
1 9 8 0 april 1980
1 9 8 3 1983

-preliminary-

Well-known pyramidal power amplifier developed... not only by Yamaha.

The "X-Power" scheme which is the center of the B-6 was apparently developed by Nissho Electronics Corp. and first licensed to Carver and Benytone c. 1978/79, then to Yamaha.
It is possible X-Power was a joint development between Nissho and Carver but I have no details there (yet).

Benytone, the OEM arm of the Marubeni empire, was building the Carver lineups at the time and distributing them in some markets as well, including Germany.
Marubeni was also distributing at the same time its own X-Calibre separates, the MA4000 and MC4000, the accompanying tuner of which can be found in Benytone X-Calibre (MT4000) or Carver guises : TX-11 and TX-11a.

It seems however that late-adopter Yamaha didn't agree to all the license terms, or didn't implement the technology according to said license terms.
This caused Nissho to forbid Yamaha to use the X-Power system in its lineups : exit the A-960, exit the B-6, enter the A-960II - exit X-Power.

You have no idea how long it took me to get this info !


So,
X-Power works with two transistors supplying low or high voltage to capacitors which also are each set for high or low voltage supply of the amplifier and a TRIAC which switches between high or low supplies depending on input signal and output needs.
The result is astounding output power capacity but... not necessarily good sound.

Bob Carver named his version of the system Magnetic Field amplifier - read this diyaudio thread for more about them and therefore more about the Yamaha B-6... and the Benythone MA4000.


Despite its Darth Vador design, the B-6 didn't sell as well as it probably was planned to.
And unlike many contemporary Yamaha components, the B-6 failed to garner any Best Product distinction during its short life - not even a Good Design award.
The B-6 was made to power sounds coming from the C-6 preamplifier but both vanished rather rapidly, especially the latter.


The B-6 is a bit blunt, to tell the truth, and thanks to Yamaha's usual laziness regarding color and texture in design, the B-6 visually doesn't age too well : painting it basic black was a bad (and cheap) idea.


-preliminary-

Yamaha B-6, image 1 Yamaha B-6, image 2 Yamaha B-6, image 3
Yamaha B-6 specifications
Title Value
Power : 2x 200W (20Hz...20Khz ; 8 Ohm ; 0,003% THD)
Power bandwidth : 10Hz...100Khz (100W ; 8 Ohm ; 0,002% THD)
Frequency response : 0dB (10Hz ; DC mode, 8 Ohm)
0dB (1Khz ; DC mode, 8 Ohm)
DC...100Khz (+0 / -0,5dB ; 8 Ohm)
Damping factor : 200 (8 Ohm / 1Khz)
Input : 1,41V / 25kOhm
THD : 0,003% (20Hz...20Khz ; 8 Ohm ; 100W)
IMD : 0,003%
S/N ratio : 127dB
Stereo separation : 95dB (20Hz)
95dB (1Khz)
75dB (20Khz)
PC : 200W (US models ; 1% THD ; 1/10 output power)
1200W (EU models ; 1% THD)
Dimensions : 29 x 17,65 x 29cm
Weight : 9kg (US model)
9,2kg (U model)
Listprice : 190,000¥ (1980)
page online since : 2007
page updated : 2010
page type : LGT / KNB
page weight : 157.78 Kb / 0 b
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