Audio Database

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
Harmonic distortion factor
(20 Hz ~ 20 kHz, 8 Ω load)
At rated output :
-3dB output :
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
Power consumption No input :
8 Ω load at rated output :