Audio Database


150,000yen(1973 release)

It is the control amplifier used as DA-A100 and a pair.

By adoption of irregular 2 power sources (+75V, -12V), the base electric potential of the first rank transistor is the same as that of ground electric potential. Since the leak current of a coupling capacitor is lost by this and also base bias is supplied from the ground, excessive current will not flow into a cartridge at the time of a power-source injection.

By making power supply voltage high with 86V, and choosing a profit moderately, even if an allowable input is large (260mV), the gap in the high region in a RIAA curve is not generated.

The BAX type is adopted as tone control.
A little surges at the time of change are lost, and also it is designed at the time of a tone control flat become the same as the state where the defeet was carried out.

The amplifier for tone control is performing voltage magnification in two steps by the combination of differential amplifier and emitter grounding. Thereby, those with about 70dB, and also when it boosts, an open-loop gain requires sufficient NFB and is suppressing distorted aggravation.

It is a system which does not change the sound quality which is to foundations by making a signal course the same at the time of a tone control operation and cancellation.

Monitor amplifier is built in.
Especially the amplifier circuit for a monitor and Line out is designed it be equal to a low load impedance (100ohms or more) or long-distance wiring (for it to be 200m with a shield line).

Rating of a mode
Form Preamplifier
Input sensitivity/impedance Phono1, 2:2mV/50kohm
Tuner, Aux1, 2, Tape P.B.1, 2:150mV/100kohm
Output sensitivity / impedance Main out1 and 2:1V/50 ohm
Line out: 1V/47 ohm
Monitor: 1V/47 ohm
Tape rec1, 2:150mV/470 ohms
RIAA deflection ±0.2dB
Frequency response 20Hz - -20kHz 0.5dB
Tone control Bass: ±10dB (100Hz, 50Hz)
Treble: ±10dB (10kHz, 20kHz)
Filter Low cut:-12dB/oct(30Hz)
High cut:-12dB/oct(9kHz)
ATT -20dB
Remains noise 0.1mV
Allowable input 260mV
Equalizer input conversion noise - 118dB(V) -- the following (flat)
- 126dB(V) -- the following (A curve compensation)
The semiconductor used Transistor: 34 pieces
Diode: Ten pieces
Power source AC100V, 50Hz/60Hz
Power consumption 7.4W
Dimensions Width 476x height 180x depth of 262mm
Weight 10.4kg