Accuphase B-6
¥ 25,000 (released in 1978)
Commentary
A power bridge network developed exclusively for M-60, P-300S, and P-300.
An operational amplifier (IC) with particularly excellent high-frequency characteristics and S/N is used for the buffer and phase inversion circuit. This eliminates the need for phase correction in a wide range and suppresses sound quality degradation.
In addition to making the NF loop DC, the condenser is removed for both input and output, and the coloration is removed.
There is a caveat to this bridge network.
Since it is designed exclusively for M-60, P-300S and P-300, it cannot be used for other products even if it is an Accuphase product. It may generate large distortion or induce oscillation before the maximum output.
The speaker impedance should be 8 Ω or more. If the impedance drops at a specific frequency, a point of 5 Ω or less may cause distortion near the maximum output.
Therefore, it is recommended to check the impedance characteristics of the speaker beforehand.
Model Rating
Type | Power bridge network |
Gain | 0dB |
Maximum power output | 5.0V |
Harmonic distortion factor | 0.01% (20 Hz ~ 20 kHz at 5.0 V Output) |
Frequency characteristic | 20 Hz ~ 20 kHz + 0 -0.2 dB DC ~ 600 khz + 0 -1.0 db |
Input impedance | 100k Ω |
Output impedance | 100 Ω |
S/N | 110 dB at IFF-A, 20 Hz to 20 kHz, output 2.0 V |
Power supply voltage | 100 VAC, 50Hz/60Hz |
Power consumption | 4W |
External dimensions | Width 184x Height 77x Depth 197 mm |
Weight | 2.0kg |
Characteristics of each power amplifier bridge connection
Item | M-60 | P-300S | P-300 | ||
Rated Output (20 Hz ~ 20 kHz, 8 Ω Load) | 1,000W/ch | 450W/ch | 450W/ch | ||
|
0.03% 0.01% |
0.03% 0.01% |
0.1% 0.05% |
||
Damping factor (40 Hz, 8 Ω load) | 60 | 30 | 30 | ||
Gain (for normal use) | +6dB | +6dB | +6dB | ||
S/N (input short, IFF-A) | 112dB | 112dB | 105dB | ||
|
130W/ch 1,600W/ch |
100W/ch 800W/ch |
100W/ch 800W/ch |