Audio Database

This is a new generation integrated stereo amplifier with consideration for the playback of digital sources such as PCM and CD, based on the development technology and materials cultivated in high-grade separate amplifiers.

The output stage employs a triple push-pull configuration with six MOS FETs, allowing a sufficient margin of P D (maximum drain loss power) of 600W.
In the whole power amplifier section, the pre-stage is a differential push-pull, the next is a cascode push-pull, and the pre-drive by two transistors is a MOS. The FET is driven.
Cascode is a circuit method used in high frequency amplification circuits of tuners. It does not cause mirror effect at high frequencies and has excellent high-frequency characteristics.

The MC head amplifier, equalizer amplifier, high-level amplifier and power amplifier are all directly connected to each other to achieve high reproduction without coloring.
The problem of DC drift caused by direct connection is solved by stabilizing each unit amplifier with DC servo.

The equalizer amplifier consists of a differential input through an FET buffer, a pre-drive cascode, and a final stage Darlington. All stages are push-pull.
Low distortion can be expected over a wide range by the cascode connection excellent in high frequency characteristics of the predrive.
The power supply is strengthened by installing a constant voltage power supply section on the same board.

The head amplifier for the MC cartridge uses a full-scale configuration in which a dedicated flat amplifier is installed in front of the EQ amplifier.
The fine signal of the MC cartridge is directly input without passing through the condenser, and the low-noise element is carefully selected, and at the same time, the low impedance of the NFB loop is made to prevent noise generation.
In addition, to prevent the noise of the constant voltage circuit of the power supply from adversely affecting the signal, the elements of the constant voltage power supply are carefully selected and a thorough low-noise design is applied.
The input impedance of the MC cartridge can be switched to 3 levels of 10 Ω, 30 Ω and 100 Ω.

The signal from the input terminal is directly connected to the printed circuit board, a relay is placed at the closest position, and this relay is controlled by the logic circuit so that the signal path is connected at the shortest.
The relay uses a high-reliability crossbar twin-type relay with a gold layer on silver-palladium alloy developed especially for small-signal audio.
In addition, it is hermetically sealed to shield it from the outside air and improve durability.
The tone control is a switch-type that can get a precise curve, and it can be finely controlled by changing in 1.5 dB steps.

Equipped with a loudness compensator to compensate for energy balance at low volume.
You can choose from three different characteristics depending on your room's acoustic characteristics, speakers, and preference.

The output meter has a logarithmic compression type peak support so that the output can be read directly.

It is equipped with a tape monitor switch that can connect two recorders and monitor recording and sound being recorded, and a switch that can dub between two tape recorders regardless of the program source selected by the input selector.

Features include a subsonic filter, an attenuator that lowers the volume without changing the volume, two speaker switches, and a mode switch.

The natural rosewood cabinet was sold separately.

Model Rating
Type Integrated Stereo Pre-Main Amplifier
continuous average power (EIA, both channel operation,
20 Hz ~ 20 kHz, Distortion Rate 0.01% or Less)
4 ohm load : 200W/ch
8 Ω load : 150W/ch
16 Ω load : 75W/ch
Total Harmonic Distortion Factor (EIA, both channel operation) 0.01% (load> 4 ω, 20 hz to 20 khz, 0.25W to rated output)
IM Strain Rate (EIA) 0.005%
Frequency Response (EIA)
Main Amp Input: 20 Hz ~ 20000 Hz + 0 -0.2 dB at rated output
1.5 Hz ~ 150000 Hz + 0 -3.0 dB at 1W output
High Level Input: 20 Hz to 20000 Hz + 0 -0.2 dB at rated output
Low Level Input: 20 Hz to 20000 Hz + 0.2 -0.2 dB at rated output
Damping Factor (EIA) 150 (8 ohm load, 50 Hz)
Input Sensitivity / Impedance
(Rated Output / EIA1W output)
Disc MM (Head amp off) : 2.7mV/0.22mV/47k Ω
Disc MC (Head amp on) : 0.085mV/0.007mV/10, 30, 100 Ω
Tuner, Line, Tape play : 170mV/13.9mV/20k Ω
Main amp input : 1.4V/0.12mV/20k Ω
Disk Max Input
(1 kHz, 0.005% distortion)
Head Amp Off:300mVrms
Head Amp On:9.5mVrms
Rated Output / Output Impedance Pre Output : 1.4V/200 Ω
Tape Rec Output : 170mV/200 Ω (for DISC)
Headphones : 0.4 v, Applicable Impedance 4 ~ 100 Ω
Gain Main Input → Output : 27.8 dB
High Level Input → Pre Output : 18.4 dB
DISC Input (Head Amp Off) → Tape Rec Output : 36 dB
DISC Input (Head Amp On) → Tape Rec Output : 66 dB
S/N, input conversion noise
Input Short A-Compensation EIA
at rated input Input Conversion Noise
Main Amp Input: 123dB -120dBV 102dB
High Level Input: 105dB -120dBV 82dB
DISC(Head Amp Off): 86dB -137dBV 80dB
DISC(Head Amp On): 72dB -153dBV 80dB
Tone Controls 10-step control
Turnover Point Bass : 200 Hz, 500 Hz
Treble : 2 kHz, 7 kHz
Bass 500 Hz : ± 7.5 dB (100 Hz), 1.5 dB step
200 Hz : ± 7.5 dB (50 Hz), 1.5 dB steps
Treble 2 kHz : ± 7.5 dB (10 kHz), 1.5 dB step
7 kHz : ± 7.5 dB (50 kHz), 1.5 dB steps
Loudness Compensator
(Volume -30dB)
Comp 1:+3dB(100Hz)
Comp 2:+6dB(100Hz)
Comp3 : + 8 dB (100 Hz), + 6 dB (20 kHz)
Subsonic Filter 17 Hz, -12dB/oct
Attenuator -20dB
Power Meter Logarithmic Compression Peak Level Display
Direct reading of output at dB and 8 Ω load
Load Impedance 2 to 16 ohms
Semiconductors used Transistors : 108
FET : 23
IC : 17 pcs
Diodes : 103
Power Supply 100 VAC / 117 V / 220 V / 240 V, 50Hz/60Hz
Power Consumption No input : 90W
Electrical Appliance and Material Control Law : 320W
8 Ω load at rated output : 550W
External Dimensions Width 445x Height 160 (including legs) x Depth 370 mm
Weight 20.5kg
Sold separately : Wood Cabinet A-8 (¥ 16,000)
External Dimensions Width 466x Height 190x Depth 385 mm