Audio Database


60,000yen(around the 1976 time)

It is a preamplifier of Feature series.

the power source according to right-and-left channel, and each unit amplifier -- right and left -- it has separate monophonic composition and volume and switches are used enough in consideration of a separation.
This has improved the separation.

While lessening the attached circuit leading to sound quality degradation as much as possible and aiming at an improvement of a separation, the constant-voltage power source was adopted as the power source of the core of amplifier, and the mutual intervention between each circuit is lost.

While a voltage amplification degree is large in a tone circuit and adopting few distorted current mirror circuits by symmetrical drive, the inverted Darlington emitter follower circuit was adopted as the filter circuit, and the low distortion is realized.

The low noise transistor which the Diatone developed was adopted as the first rank differential amplification stage of equalizer amplifier, and the value of input conversion noise-126dB(V) (IHF, A curve compensation) has been acquired.

An original variable resistor with a switch is adopted as tone control, and a damping time constant circuit is separated completely and it has the composition that a flat frequency response is acquired in the flat position.

each channel of right and left of "tone control volume" -- it has prepared separately. And an improvement of a separation is aimed at and right and left separate tone control is possible.

The muting circuit of reed relay use was adopted and the noise at the time of power switch ON-OFF is prevented.

By remote control, the direct speaker change of power amplifier is possible.

Docking with the power amplifier of Feature series is possible.

Rating of a mode
Form Preamplifier
Input sensitivity/input impedance
Phono1, 2 : 2.2mV/50kohm
Tuner: 150mV/60kohm
AUX: 150mV/60kohm
Play: 150mV/60kohm
Phono maximum permissible input 270mV (1kHz, 0.1% of THD)
An Output voltage/Output load impedance
Pre Out (at the time of 50kohm load) : Rated 1V/600 ohm
A maximum of 9V/600ohm
Head Phone (at the time of 8-ohm load) : 50mV of rating
(Pre Out 150mV o'clock)
Rec: 150mV/680 ohms
THD (20Hz - 20kHz) At the time of 1V output: 0.02% or less
At the time of 9V output: 0.05% or less
Frequency response
Phono (RIAA deflection) : 30Hz-15kHz±0.2dB
Tuner, AUX, Play 10Hz-70kHz 0dB-0.5dB
Channel separation
Phono 1kHz : 100dB or more
20kHz : 80dB or more
Tuner, AUX, Play 1kHz : 100dB or more
20kHz : 85dB or more
Tone control Bass: ±10dB (100Hz)
Treble: ±10dB (10kHz)
Subsonic Filter Low: 18Hz, 12 dB/oct
Input conversion noise
(IHF, A network, input short-circuit)
Phono: -126dB
Tuner, AUX, Play : -106dB
The number of the semiconductors used FET:3
Transistor: 34
Diode: 15
Power source AC100V 50Hz/60Hz
Power consumption
(Electrical Appliance and Material Control Law)
Dimensions Width 425x height 169x depth of 204mm
Weight 5.8kg