Audio Database

A pre-main amplifier with a current feedback amplifier circuit in the power amplifier section.

The amplifier uses a current feedback type amplifier circuit that feeds back the output signal in the form of a current.
The principle is that a current is detected by lowering the impedance of the input terminal on the feedback side, and the current is converted into I-V by a transimpedance amplifier to produce an output signal. Since the impedance of the feedback input is extremely low, phase rotation is less likely to occur.
Since there is almost no need for phase compensation, it has excellent dynamic characteristics such as start-up and natural energy response.
In addition, high power is obtained by using a parallel audio power transistor for the output element, which has excellent characteristics such as frequency characteristics, linearity of current amplification factor and switching.

The power supply is equipped with a large power transformer with a high power capacity of approximately 500 VA and a large filter capacitor of 22,000 μ Fx2.

The line amplifier is composed of discrete parts. Basically, it has AccuPhase's original differential-pure complimentary service push-pull input, and the output-stage is finished a single-ended push-pull emitter-follower.

An equalizer amplifier with a dedicated input circuit is used in consideration of the characteristics of each MC and MM type cartridge.
Since the output voltage and output impedance of the cartridge are high at MM input, it is composed of an FET element that can maintain high input impedance over all frequency standby.
In addition, since the MC input receives very small signals with low impedance, a differential input circuit with low-noise elements is constructed to reduce the impedance of the NFB loop, enabling low-noise reproduction.

A logic relay control method is used to prevent signal degradation due to switching of the input selector, etc. and to configure the shortest and straight signal path.
The relay used is a sealed type for the communication industry. The contact is a gold-plated cross-bar twin type and realizes low contact resistance and high durability.

Two balanced inputs are available for balanced transmission.

The volume control features a high-quality volume and a small motor with clutch for smooth operation.
The included remote control allows volume adjustment by motor and input selector control by logic circuit.

A selector switch and input / output terminals are provided so that the preamplifier and power amplifier can be used independently.

Equipped with a large peak power meter to monitor output power.
Since the meter is logarithmic compression type, you can check a wide dynamic range at one time.

Uses a large speaker terminal that can handle thick speaker cables.
A banana plug can also be inserted into this terminal.

Model Rating
Type Integrated Stereo Pre-Main Amplifier
Rated continuous average power
(simultaneous operation of both channels, 20 Hz to 20 kHz)
4 ohm load : 140W/ch
6 Ω load : 120W/ch
8 Ω load : 100W/ch
Total harmonic distortion factor (simultaneous operation of both channels) 0.04% (4-16 Ω load)
IM Distortion Factor 0.01%
Frequency Special
(at rated continuous average power)
Main/High Level Input : 20 Hz to 20000 Hz + 0 -0.2 dB
Low Level Input : 20 Hz to 20000 Hz + 0.2 -0.5 dB
Damping factor 120 (8 ohm load, 50 Hz)
Disk Max Input
(1 kHz, 0.005% distortion)
MM Input : 250 mVrms (Rec Out)
MC input : 7.0 mVrms (Rec Out)
Input Sensitivity / Input Impedance
Input Sensitivity Impedance
At rated output EIA at 1W output
AD Input(MC): 0.11mV 0.01mV 100 ω
AD Input(MM): 3.9mV 0.39mV 47k Ω
High Level Input: 113mV 11.3mV 20k Ω
Balanced Input: 113mV 11.3mV 40k Ω
Main Amp Input: 1.11V 112mV 20k Ω
Output Voltage / Output Impedance
(at rated continuous average power)
Pre Output : 1.11V/50 Ω
Tape Rec Output : 110mV/200 Ω (from AD)
Gain Main Input → Output : 28 dB
High Level Input → Pre Output : 20 dB
AD Input (MM) → Tape Rec Output : 29 db
AD Input (MC) → Tape Rec Output : 60 dB
S/N, input conversion noise
  • AD Input(MC):
  • Input Short A-Compensation EIA S/N
    S/N at rated input Input Conversion Noise
    Main Input: 124dB -121dBV 102dB
    High Level Input: 110dB -128dBV 83dB
    Balanced Input: 90dB -108dBV 82dB
    AD Input(MM): 85dB -132dBV 80dB
    70dB -146dBV 78dB
    Loudness Compensator + 6 dB (200 Hz, Volume-30dB)
    Subsonic Filter 25 Hz, -12dB/oct
    Power Meter Logarithmic Compression Peak Level Display
    Direct reading of output at dB scale and 8 Ω load
    Load Impedance 4-16 ω
    Stereo Headphones Applicable Impedance : 4 Ω ~ 100 Ω
    Power Supply 100 VAC, 50Hz/60Hz
    Power Consumption No input : 50W
    Electrical Appliance and Material Control Law : 290W
    8 Ω load at rated output : 390W
    External Dimensions 475 mm wide x 170 mm high x 418 mm deep
    Weight 20.2kg
    Included : Remote Commander RC-14
    Remote Control Method Infrared Pulse Method
    Power Supply DC 3V
    Dry Battery AAA 3 (SUM-3/R6) 2 pcs
    Maximum External Dimensions 45 mm wide x 136 mm high x 18 mm deep
    Weight 85g (including dry batteries)