Diatone DA-A100, 1973, made in Japan

Link: audio-database


250,000yen(1973 release)

Description
It is the stereo power amplifier used as DA-P100 and a pair.

2 block configurations which prepare a voltage amplifier before an electric power amplifier are adopted.
This has solved the problem of power amplifier including S/N and distortion sharply with stable NFB.

The high thing of fa (high region cutoff frequency) with the sufficient linearity of hFE (direct-current current gain) is selected carefully and used for a power transistor. This has realized the power ratio 3.0.
Furthermore, the results of having excelled in sound quality, such as reduction of notch distortion, have been obtained by using it by a single push pull.

A power-source part is considered as a thing of a magnification stage and one, is aiming at improvement in a quality of the part itself, and is aiming at improvement in the whole.
The not a transformer but cut core of EI structure with many losses are adopted as a power transformer. Moreover, improvement in a regulation is aimed at by enlarging capacity with 400VA.
Moreover, in order to acquire the Oide power of the 4-ohm load 150W, impedance has adopted as the filter capacitor of a power source enough what can send large current low. The electrostatic capacity of 22000 micro F and the current capacity 36A are carrying out thing adoption at the capacitor.

It is the design in which the protection circuit operates at radiator (radiator) 100 degree C.

One power transistor is equipped with one unusual detector circuit.

Form Stereo power amplifier Output - Both channel operation : 150W+150W (4ohms) 100W+100W (8ohms) - One-side-channel operation : 180W/180W (4ohms) 110W/110W (8ohms) - Music power : 450W (4ohms) 250W (8ohms) - EIAJ: 340W (4ohms) 220W (8ohms) THD 0.1% (at the time of an Output power) Cross modulation distortion 0.15% (at the time of an Output power) Input sensitivity/impedance 1V/100kohm Power bandwidth 20Hz - 20kHz Frequency response 10Hz - -30kHz 0.5dB Remains noise 0.25mV Dumping factor 200 The semiconductor used Transistor: 35 pieces Diode: 25 pieces Power source AC100V, 50Hz/60Hz Power consumption 205W Dimensions Width 360 x height 223 x depth of 268mm Weight 16kg