Audio Database

The

DIATONE DA-A7
60,000yen(around the 1976 time)

Description
 
Power amplifier of the Feature series which the Diatone put on the market.

The 2 steps of differential amplification current mirrored live system is adopted, and low distortion-ization especially at the time of a small signal is thought as important and designed.
The improvement of the nakedness characteristic is aimed at with the combination of high gain, the current mirror circuit of a low distortion, and the good power transistor of linearity, and still more sufficient NFB has realized the low distortion.

The standup characteristic of a pulse is improved by the high transistor and the current mirrored live of ft.

One power transformer of 300VA and two electrolytic condensers (63V and 18000 micro F) are carried in the power-source part.

Effective heat dissipation is realized by arranging exothermic parts, such as a heat sink and a power transformer, to the chassis exterior.

The temperature of the power transistor is stopped low enough using the heat sink of 0.5 degree C per channel/W.

The speaker change is using the relay for protection as it is.
This starts the fall of a dumping factor like the conventional speaker changeover switch.

The preamplifier of Feature series, docking, and remote control are possible.


Rating of a mode
Form Stereo power amplifier
Output
Both channel operation, 20Hz - 20kHz : 75W+75W (8ohms)
110W+110W (4ohms)
Both channel operation, 1kHz : 85W+85W (8ohms)
120W+120W (4ohms)
one side channel operation, 1kHz : 95W/95W (8ohms)
140W/140W (4ohms)
Music power : 200W (8ohms)
360W (4ohms)
EIAJ (distorted 5%) : 180W (8ohms)
280W (4ohms)
THD 0.1% (at the time of an Output power)
0.02% (at the time of 1W output 20Hz - 20kHz)
0.003% (Output-power-3dB o'clock, 1kHz)
Cross modulation distortion (1W, 50Hz:7kHz=4:1) 0.03%
Input sensitivity/impedance 1V/50kohm
Frequency response (0.5W, -0dB one dB) 10Hz - 50kHz
Output bandwidth (IHF 0.1% distortion) 10Hz - 50kHz
Dumping factor 100
Channel separation 85dB(1kHz)
60dB(20kHz)
Remains noise 0.25mV
Muting time 5 seconds
Conformity load impedance 4-16ohm
Power source AC100V 50Hz/60Hz
Power consumption 185W (Electrical Appliance and Material Control Law)
270W (at the time of an Output power (8ohms))
Dimensions Width 425x height 170x depth of 225mm
Weight 11.5kg