Commentary　

This stereo preamplifier was developed by gathering together carefully selected elements and development technologies accumulated over many years.
It has a balanced input / output circuit.

The high-level flat amplifier that handles signals other than analog disks employs a cascode differential input and a class A push-pull output stage to improve various characteristics.
This amplifier has XLR-type balanced connectors for input and output, making ideal balanced transmission possible.

The equalizer amplifier has a dedicated input circuit for each MC and MM type cartridge.
Considering that the output voltage and output impedance of the MM cartridge are high at the time of MM input, an FET para-input circuit is used to maintain high input impedance over the entire frequency band.
Since the signal voltage at the MC input is low, it is important to improve the S/N ratio. Therefore, the input circuit is composed of carefully selected elements with low intrinsic noise.
These switching are done by relay, and at the same time, the amplification degree is also switched according to MM/MC.

In order to configure the shortest and straight signal path, a relay is installed in the signal path necessary for switching, and switching is performed by the logic relay control method which controls the relay electronically.
Consideration is also given to the important quality of the relay, and a sealed relay developed especially for audio applications is used. The contact is a crossbar twin system with low contact resistance and high durability.

The input source and volume can be adjusted with the included remote control.
In order to prevent deterioration of sound quality at this time, the relay is switched electronically for input switching, and a manual volume with less deterioration of sound quality is rotated by a motor for volume adjustment.

We have developed and installed a tone control that uses an additive filter with excellent characteristics.
The principle of this tone control is that an original flat signal passes through straight, and another characteristic is created according to the necessity, and is added or subtracted from the flat signal, which is advantageous in tone quality.
In addition, high-quality elements are used in combination to emphasize sound quality, and an ON-OFF switch is provided to pass the circuit when it is OFF.

It is equipped with a loudness compensator to compensate for the perception that the amount of bass sound is reduced at low volume due to human auditory characteristics.
The characteristics are linked to the volume adjustment and automatically control the amount of increase.

Equipped with a recording selector, you can record another source while watching.

Model Rating

Type	Stereo Preamplifier
Frequency Response	Balanced Input: 1.0 Hz to 400 kHz + 0 -3.0 dB 20 Hz ~ 20 kHz + 0 -0.2 dB Unbalanced Input: 1.0 Hz to 500 kHz + 0 -3.0 dB 20 Hz ~ 20 kHz + 0 -0.2 dB AD Input: 20 Hz to 20 kHz ± 0.5 dB
Total Harmonic Distortion Factor	0.005% (at all input terminals)
Input Sensitivity (Rated / 0.5 v Output) / Impedance	Balanced : 126mV/31.5mV/40k Ω (20k Ω / 20k Ω) Unbalanced : 126mV/31.5mV/20k Ω AD MM : 4.0mV/1.0mV/47k Ω AD MC : 0.13mV/0.032mV/100 Ω
Rated Output / Impedance	Balanced Output : 2.0V/50 ω (25 ω / 25 ω), XLR connector Unbalanced Output : 2.0V/1 ohm, RCA phono jack Tape Rec : 126mV/200 Ω, RCA phono jack (at AD input)
Headphone jack	Applicable Impedance : 4 Ω ~ 100 Ω
S/N ratio (S/N / EIA S/N at rated input)	Balanced:97dB/91dB Unbalanced:110dB/91dB AD MM:90dB/84dB AD MC:74dB/83dB
Input Conversion Noise	Balanced:-115dBV Unbalanced:-128dBV AD MM:-138dBV AD MC:-152dBV
Maximum power level (0.005% distortion rate, 20 Hz to 20 kHz)	Balanced Output : 8.0 v, XLR-type connector Unbalanced Output : 8.0 v, RCA phono jack Tape Rec : 8.5 v, RCA phono jack (AD input)
AD maximum input voltage (1 kHz, 0.005% distortion)	MM Input:270mV MC Input:8.5mV
Minimum Load Impedance	Balanced Output : 600 Ω Unbalanced Output : 1k Ω Tape Rec : 10k Ω
Tone Controls	Bass : 300 Hz, ± 10 dB (50 Hz) Treble : 3 kHz, ± 10 dB (20 kHz)
Gain	Balanced Input →Balanced Output →Unbalanced Output →Rec Output :24dB :24dB :0dB Unbalanced Input →Balanced Output →Unbalanced Output →Rec Output :24dB :24dB :0dB AD MM Input →Balanced Output →Unbalanced Output →Rec Output :54dB :54dB :30dB AD MC Input →Balanced Output →Unbalanced Output →Rec Output :80dB :80dB :60dB
Loudness Compensator (Volume-30dB)	+6dB(100Hz)
Subsonic Filter	17 Hz, -12dB/oct
Attenuator	-20dB
Semiconductors used	37 transistors FET : 16 IC : 33 Diodes : 59
Power Supply	100 VAC / 117 V / 220 V / 240 V, 50Hz/60Hz
Power Consumption	28W
External Dimensions	Width 445x Height 95 (including legs) x Depth 325 mm
Weight	9.3kg
Included : Remote Commander RC-3
Remote Control Method	Infrared Pulse Method
Power Supply	DC3V
Dry Battery	SUM-3 (IEC designation R6) 2 pieces
Maximum External Dimensions	64 mm wide x 149 mm high x 18 mm deep
Weight	140g (including dry batteries)