Audio Database


65,000yen( at the 1970 in-the-late time(?))

The Integrated Amplifier which adopted DC scheme.

DC scheme is adopted as a power amplifier part.
Dual FET to which the property was equal is adopted as the first rank of DC power amplifier part, and the pure complimentary OCL circuitry and the conjointly excellent tone quality are realized. Moreover, about the drift of the middle point potential which poses a problem with DC amplifier, a power supply variation is suppressed in each stage, a pair property is raised, and the stability is improved.

Taking advantage of the merit of the tone quality of Class-A amplifier, AB class operation method which can acquire the Oide power is adopted.
Usually, it is a Class-A operation at the time, and it changes to B class operation automatically at the time of the Taishin number which needs big power.

The low distortion is realized by investigating thoroughly until it results in the design of the printed circuit board, or a placement of a shielding code including a material or component partses.

As a protection network, the electro carry control ASO (area of safe operation) circuitry and DC feedback power limit circuitry are carried. The electro carry control ASO circuitry has protected the transistor and speaker of amplifier by relay operation. Moreover, the DC feedback power limit circuitry operated quickly to the overload, and has protected the transistor.

The peek indicator by light emitting diode is carried. 13 light emitting diodes per channel were adopted, power was transposed to digital one, and the quick window is realized.
Since the sensitivity switching (-20dB) organization and the off-switchpoint are equipped, it reads easily also at the time of a small sound volume, and the indicator window can also erase an indicator, when unnecessary.

MC head amplifier is carried.
The head amplifier adopted as RA-2020 has adopted the three-step parallel coupled circuitry by low-noise FET as the input unit.

IC circuitry which made the first rank the Class-A differential and made the output stage the push pull is adopted as an equalizer-amplifier part.

DC amplifier scheme is adopted as a tone control circuit. Moreover, it is possible to cancel a tone circuitry and to also make it operate as flat buffer amplifier with a tone-defeat switchpoint.

The Subsonic Filter and the supersonic filter are carried.

The termination by which the gilding treatment was carried out is adopted.

The front panel serves as EIJ specification rack-mounted type.

Rating of a mode
Form Integrated Amplifier
<Power amplifier part>
Output power (both channel drive) 85 W/ch (4 ohm, 1kHz)
60 W/ch (8 ohm, 20Hz - 20kHz)
THD 0.02% (at the time of an Output power 20Hz - 20kHz)
Cross modulation distortion 0.02% (at the time of an Output power 8ohms)
Frequency characteristic (1 W/ch, 8ohm) 2Hz-160kHz+0 -3 dB
Input sensitivity/impedance 1V/50kohm
Dumping factor (8ohms) 50 (20Hz - 20kHz)
S/N ratio (IHF-A network short-circuit) 100dB
Crosstalk (10kHz) 57dB
<Equalizer part>
THD Phono MAG:0.006%
Phono MC:0.008%
RIAA deflection (20Hz - 20kHz) ±0.5dB
Input sensitivity/impedance Phono1 MAG: 2mV / 50kohm
Phono2 MC: 200 microvolts/150 ohm
Maximum permissible input (1kHz, THD0.5%) Phono MAG:200mV
Phono MC:5mV
<Preamplifier part>
THD 0.01% (at the time of an Output power 20Hz - 20kHz)
Frequency characteristic 5Hz - 120kHz
S/N ratio (IHF-A network) Tuner, Aux: 92dB
Tape monitor:92dB
remains noise (at the time of a volume min) 8 microvolts, 100dB
Input sensitivity/impedance Tuner, Aux:150mV /, 50kohm
Tape monitor: 150mV / 50kohm
Maximum permissible input (1kHz, THD0.5%) Tuner, Aux:15V
Tape monitor:15V
Slew rate 30V/muS
Square wave rise time 3microS
<Control property>
Control width Bass: ±10dB (100Hz)
Treble: ±10dB (10kHz)
Supersonic filter 24kHz, 12dB / oct
Subsonic Filter 15Hz, 12dB / oct
Maximum electric power consumption 450W
Dimensions Width 482x height 143x depth of 328mm
Weight 13kg