Commentary

This control amplifier was released as the first of the Accuphase series. The company name at that time was Kensonic.

The equalizer circuit is fully push-pull driven by direct connection to all stages to improve the bare characteristics before NFB (negative feedback) is applied, making it a high fidelity amplifier circuit.
To handle input signals in a wide dynamic range, an A-class drive pure complimentary service is used in the final stage of the equalizer, and a dual plus / minus power supply system ensures a high allowable input voltage.
In addition, a low-enhancement circuit is used to enhance the sense of volume when listening to music.

An attenuator that can be continuously adjusted by 10 dB is provided to adjust the level of the DISC1 and DISC2 cartridges when you want to lower the level of an extremely high-power cartridge to an appropriate level, or when you want to listen to a comparison of two cartridges using DISC1 and DISC2.
In addition, DISC1 is equipped with an input impedance selector switch, which allows you to select between 47k Ω, 30k Ω and 20k Ω.
A 25-Hz cutoff subsonic filter is also provided for disc playback.

Equipped with independent left and right tone control, the turnover frequency can be switched between 200 hz, 400 hz, 2.5 khz and 5 khz for low and high tones respectively.
The change characteristic is ± 10 dB with a 11-contact rotary switch.

It is equipped with a low filter of 12dB/oct at 30 Hz or less to cut subsonic noise.
It is also equipped with a 5 khz, 12dB/oct high filter to cut hissing from tapes.

Tape I/O is installed in the Route 3 so that three tape recorders can be connected.
Two of them are capable of dubbing each other. The copy switches are independent, so that it is possible to dub each other while listening to the source.

A dedicated amplifier directly connected to pure complimentary service is installed for the headphone to improve the sound quality of the headphone.

All amplification stages are supplied from a power supply with a completely constant voltage to improve stability.

The speaker selector switch on the front panel allows you to switch the speaker system using a special relay box (sold separately) when the power amplifier is set out of reach.

Model Rating

Type	Accuphase stereo control amplifier
Frequency Response	High level input : 20 Hz to 20000 Hz, + 0 -0.2 dB DISC and MIC input : 20 Hz to 20000 Hz, ± 0.2 dB
Harmonic Distortion Factor	0.05% or less (between 20 Hz to 20000 Hz at rated output)
Input Sensitivity / Input Impedance	DISC1 : 2 ~ 6mV/20k Ω, 30k Ω, 47k Ω DISC2 : 2 ~ 6mV/47k Ω MIC : 2mV/47k Ω Tuner : 200mV/130k Ω AUX1, 2, Front : 200mV/130k Ω Tape Play1, 2, Front : 200mV/130k Ω
Rated Output / Output Impedance	Main Output : 2.0V/200 Ω Headphones : 0.4V/0.3 Ω (maximum volume adjustment, at rated input) Tape Rec Output1, 2, Front : 200mV/200 Ω (at DISC input) Mono Output : 0.42V/38k Ω
Maximum Power Level	10 v or more (distortion factor 0.05%)
Disk Max Input	400 mv ~ 1.2 vrms (1 khz, distortion 0.05%) * 400 mv is the maximum DISC level control (equalizer gain 40 db) * 1.2 v is DISC level control minimum (equalizer gain 30 db)
Gain	From the Tuner, AUX, and Tape Play inputs 　 Tape Rec Output: Main Output: Headphone: 0dB 20dB 6dB From DISC1, 2 and MIC input 　 Tape Rec Output: Main Output: Headphone: 40dB 60dB 46dB
S/N (Rated Output, Volume Adjustment Maximum)	Tuner, AUX, Tape Play : 90 dB or higher (nominal input) DISC, MIC : 74 dB or more (10 mV input)
Volume Adjustment Interlock Error	within 1 dB
Tone Controls	Low : Change Point 400 Hz : 200Hz: ± 10 dB (100 Hz) ± 10 dB at 50 Hz High : Change point 2.5 kHz : 5kHz: ± 10 dB at 10 kHz ± 10 dB at 20 kHz
DISC low enhancement (volume compensation circuit)	0 dB, + 0.5 dB, + 1 dB (100 Hz) from the RIAA reference characteristic
Compensator (volume control -30dB)	50Hz:+10dB
Filters	DISC subsonic filter : 25 Hz, 6dB/oct Low Filter : 30 Hz, 12 dB / High Filter : 5 kHz, 12dB/oct
Semiconductors used	transistor : 80 Diode : 35
Power Supply	100 V, 117 V, 220 V, 240 V, 50Hz/60Hz
Power Consumption	36W
External Dimensions	445 mm wide x 152 mm high x 355 mm deep
Weight	14kg