Audio Database


69,800yen(around the 1979 time)

DC Integrated Amplifier which has discerned the true nature of an audio amplifier called a music play, and carries a diamond differential circuit.

It is the design which raised amplifier part DC-ization further, and all of an equalizer part, a flat amplifier part, and a power amplifier part are considered as DC amplifier stream composition which was excellent in the dynamic behavior.
And the input of the whole-block stage is made into a push pull input circuit in an all FET input, and serves as a direct couple scheme which eliminated the input capacitor of the whole-block stage.
The factor of tone-quality failures, such as a low-pass phase rotation which this cuts with a capacitor going into a signal path, was lost, and a pure transmit and wide-range-izing of a music signal are realized.

The diamond differential circuit is carried in the power amplifier part.
The diamond differential circuit according the differential circuit with constant current of a Dual-FET using which can send a large current through the first rank in a low-noise property to a cascode bootstrap to the 2nd step is used for circuitry, respectively.
And NM (Non Magnetic) transistor with the sufficient linearity in a power stage was used, and since it is 2pole phase compensator while the whole circuitry consists of symmetrical symmetrical networks, little waveform transmission distorted to a RF area has been realized.

The circuitry of an equalizer-amplifier part is the direct couple scheme which removed the input capacitor leading to a tone-quality failure,For the first rank, stability uses the Dual FET of a low-noise, and a high and gm highly, and serves as a push pull drive by two steps of differentials, and an electric-current differential with a current mirror, and a pure contest SEPP output at it.
Moreover, the equalizer element of NF circuitry has little highly precise metals skin membrane resistance and capacity error, and the styrene capacitor excellent in the temperature characteristic is adopted.

The flat amplifier part has also adopted the direct couple scheme which removed the input capacitor which is not effective in tone quality.
The first rank is the cascode interconnection and the differential amplification with the current source which use the Dual FET of a low-noise, and a high and gm,The 2nd step has 8 stone composition of the electric-current differential push-pull-circuit adoption with a current mirror, and has the composition that the open loop property aiming at a reduction of TIM distortion was excellent like DC power amplifier part.
Moreover, if tone-on is used, it will change from flat amplifier to NF type tone amplifier, and few gentle and distorted tone control properties will be acquired.

The power-source part considered it as 2 power transformer, and has adopted the right-and-left full independence scheme.
Moreover, the low-impedance property from super-low-pass one to a super-high region is attained by using the electrolytic capacitor and metallized film capacitor of 12,000 micro Fx4.

MC head amplifier is carried.

The loudness switchpoint, the Subsonic Filter, the tone defeet switchpoint, and the balance control are carried.

It is also possible to be able to perform independently a tapes play functionality and a tape copy, and to take out the signal of a tuner independently moreover at the time of a sound recording.
For example, an air check etc. is possible, hearing a record.

A two-line interconnection of OFF, A, B, and A+B is possible for a speaker output.

Standby AC plug socket 3 circuitry (interlocking 1 circuitry 100W, 2 non-interlocking circuitry 250W) and the grounding terminal are carried.

It is possible to separate power from a pre.

Power A

Rating of a mode
Form Wide-range DC Integrated Amplifier
<Power amplifier part>
Effective output 70W+70W (10Hz - 20kHz, THD 0.008%, 8ohm)
70W+70W (1kHz, THD 0.003%, 8ohm)
THD 0.008% or less (at 10Hz - 20kHz, the time of an effective output 8ohm)
Cross modulation distortion (70Hz:7kHz=4:1) 0.008% or less
Output bandwidth 5Hz - 70kHz (IHF, both channel) operation, 1kHz, 8ohm)
Dumping factor 100 (IHF, both channel operation, 1kHz, 8ohm)
Frequency characteristic DC-400kHz and +0 -3dB
Input sensitivity/input impedance 1V / 47kohm (1kHz)
SN ratio 125dB or more (IHF, A network, a short circuit)
Channel separation 90dB or more (IHF, 1kHz)
Rise time 0.5microsec
Slew rate }160v/microsec
<Preamplifier part>
Input sensitivity/input impedance
Phono-1 man-month:2.5mV /, 47kohm
Only for Phono-2 MC: 0.1mV/100 ohm
AUX, Tuner, Tape Play 1, 2 (PIN):150mV / 47kohm
MC conformity impedance 100ohms or less
Phono maximum permissible input (1kHz) Phono MM:300mV(THD 0.01%)
Phono MC:15mV(THD 0.03%)
Output voltage (1kHz) Tape Rec 1, 2 (at time of PIN and 47kohm):150mV
Pre Out(at the time of 47kohm): 1V
Max Pre Out(at the time of THD 0.05% and 47kohm): 4V
Output load impedance (1kHz) Tape Rec 1, 2:600ohms or less
THD Phono MC (1kHz, 6V): 0.01% or less
Phono man month (20Hz - 20kHz, 6V): 0.005% or less
AUX, Tuner, Tape Play 1, 2 (20Hz - 20kHz, 1V):0.005% or less
Cross modulation distortion (70Hz:7kHz=4:1) AUX, Tuner, Tape Play 1, 2 (1V):0.005% or less
Frequency characteristic RIAA deflection (Phono 1, 2 or 20Hz - 20kHz): }0.2dB
AUX, Tuner, Tape Play 1, 2:5Hz - 100kHz, and +0 -1 dB
SN ratio (IHF, A network)
Short circuit
Phono MC(input conversion): -152dBV
Phono man month: 88dB or more
AUX, Tuner, Tape Play 1, 2:100dB or more
Channel separation
(IHF, 1kHz)
Phono MC: 70dB or more
Phono man month: 70dB or more
AUX, Tuner, Tape Play 1, 2:75dB or more
The separation between inputs
(Input short-circuit, 1kHz)
Tuner<=>Phono man month: More than 90dB
Tape Play 1, 2 <=>Phono man month: 90dB or more
Tuner<=>Tape Play 1, 2:90dB or more
More than Tape Play 1 <=>Tape Play 2:90dB
Tone control Bass: }10dB (50Hz)
Treble: }10dB (15kHz)
Subsonic Filter 16Hz (-3dB, 6 dB/oct)
(Volume -30dB o'clock)
Headphone jack output 85mW (8ohm)
Load impedance 4-16ohm
Power dissipation 195W (Electrical Appliance and Material Control Law)
Dimensions Width 430x height 168x depth of 390mm
At the time of a rack-mounted adapter attachment: Width 482x depth of 418mm
Weight 15.5kg
At the time of a rack-mounted adapter attachment: 16kg
Option Rack-mounted adapter BX-7 (1 set, 3,000yen)