Commentary　

A pure Class-A stereo power amplifier using power MOS-FETs, developed by inheriting Accuphase's design philosophy and circuit technology such as constant voltage drive and low impedance.

The output stage uses power MOS FETs, and by driving 3 pairs of parallel push-pull power MOS FETs per channel, stable linear power is guaranteed even under very low impedance loads.
The parallel connection has advantages such as lowering the inherent output impedance and internal noise of the device, and dispersing the heat generated by the device. In addition, MOS FETs can efficiently use the low power range with excellent linearity, contributing to improved performance and sound quality.
The maximum clipping level is set to 50W into 8 ohms to save the occasional momentary pulse of the music signal from clipping.
The actual measured clipping power is 156W (limited to music signal) at 1Ω load, 126W at 2Ω, 85W at 4Ω, and 50W at 8Ω, with enough margin for the design.

It uses a current feedback amplifier circuit (current feedback amplifier circuit) that feeds back the output signal in the form of current.
First, the impedance of the input terminal on the feedback side is lowered to detect the current. The current is converted into I-V (current-voltage) by a transimpedance amplifier to produce an output signal.
Since the impedance of the feedback input part is low, phase rotation hardly occurs and phase compensation is hardly necessary, various characteristics can be greatly improved with a small amount of NFB, and natural energy response is possible.

The current feedback amplifier circuit has excellent stability with no phase disturbance caused by NFB, which enables gain control by NFB quantity switching method.
In this system, when the gain of the amplifier is reduced, the noise component is also reduced at the same time, so it is effective for reducing residual noise in high - and high-frequency applications of high-efficiency speakers and multi-amplifier systems.

The power supply section uses a high-efficiency, high-power capacity large transformer of approximately 400 VA. This transformer is enclosed in a case with a filler material with excellent heat conduction and anti-vibration effect to block external influences.
The aluminum electrolytic capacitor for smoothing is equipped with two 47,000 μ F high-capacity, high-sound type capacitors, which are insulated with a thick heat-shrink sleeve to absorb vibration.

Bridge connection is possible with the changeover switch on the rear panel.
In a bridge connection, two amplifiers of different polarity are fed with opposite signals, and a speaker is connected to the outputs of both amplifiers.
This allows you to upgrade to a high-power monaural amplifier. In addition, when the selector switch is in the dual mono position, it can be used as a mono output for a center woofer, or as a bi-amplifier drive for low and high frequencies by outputting a single-channel signal from both speakers.

Equipped with balanced connection terminal that is less susceptible to external induction noise.

Equipped with an analog type large power meter that can directly read a wide power range with logarithmic compression.
It is also equipped with a switch to turn ON/OFF the meter operation and lighting.

Copper is used for the parts through which signals pass, and gold plates are formed on the copper.
The quality of the printed board copper foil and input and output terminals has been improved.

It is equipped with a large speaker terminal with a metal plate made from solid brass and covered with a mold cap for insulation.

Model Rating

Type	Stereo power amplifier
Rated continuous average power (between 20 Hz and 20 kHz)	Stereo specification (simultaneous operation of both channels) 2 Ω : 80W/ch 4 Ω : 40W/ch 8 Ω : 20W/ch Monaural (bridge connection) 4 Ω : 160W 8 Ω : 80W
Total Harmonic Distortion Factor	Stereo specification (simultaneous operation of both channels) 2 Ω : 0.05% 4 ~ 16 Ω : 0.02% Monaural (bridge connection) 4 ~ 16 Ω : 0.02%
IM Distortion Factor	0.003%
Frequency Response	At rated continuous average power : 20 Hz to 20,000 Hz, + 0 -0.2 dB 0.5 Hz to 160,000 Hz at 1W output, + 0 -3.0 dB
Gain	28.0 dB (both when the GAIN switch is at MAX and when the stereo / monaural specification is used)
Load Impedance	Stereo : 2 ~ 16 Ω Monaural specification : 4 ~ 16 Ω
Damping factor	Stereo : 120 Monaural specification : 60
Input sensitivity (8 Ω load)	Stereo specification 0.50 V at rated continuous average output 0.11 V at 1W output Monaural specification 1.00 V at rated continuous average output 0.11 v at 1W output
Input Impedance	Balance : 40k Ω Unbalanced : 20k Ω
S/N (A correction)	110 dB at input short circuit, rated continuous average output
Power Meter Level	Logarithmic Compression Type with Display Light Off Function NORMAL : -40dB to + 3 dB -20dB : -60dB to -17dB
Power Supply	100 VAC, 50Hz/60Hz
Power Consumption	No input : 160W Electrical Appliance and Material Control Law : 250W 8 Ω rated output : 180W
External Dimensions	475 mm wide x 170 mm high x 426 mm deep
Weight	22.6kg