Audio Database

The

DIATONE DA-U550 43,000yen(1973 release)
45,000yen(around the 1975 time)

Description
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The Integrated Amplifier which avoided coloring in all respects of the engine performance, a function, and a design, and was developed more orthodoxly.

The pure complimentary OCL circuit of one step of differential is adopted as circuit composition, and change of sound quality is suppressed by simplifying the course along which a signal passes as much as possible.
Moreover, the margin was given to all the parts and especially the power transistor has adopted what raised Pc40W and a rank. Moreover, the somewhat larger thing than the conventional thing is adopted also about a radiator.

In order to be able to drive a speaker in the best state certainly, the drive of the speaker of low impedance is also taken into consideration and designed.

it is possible to have the separation terminal of a preamplifier output and a power amplifier input, and to come out and for even a slide switch to use it, dissociating

The high proof-pressure low noise silicon transistor is adopted as an equalizer circuit.

A Media Interface Connector input terminal and two REC terminals are carried.

BAX type modification is used for tone control. The variable system is a click stop type of 11 positions.
Moreover, loudness control and a high cut filter are carried.

There was a wood case as an option option.

At

Rating of a mode
Form Integrated Amplifier
<Power amplifier part>
Output
Both ch operation : 26W+26W (4ohms)
20W+20W (8ohms)
Single-sided ch operation : 32W/32W (4ohms)
24W/24W (8ohms)
Music : 62W (4ohms)
50W (8ohms)
EIAJ: 60W (4ohms)
THD 0.8% (at the time of an Output power)
0.06% (at the time of 1W output)
Cross modulation distortion 0.18% (at the time of 1W output)
Power bandwidth 10Hz - 50kHz
Frequency response 10Hz - -50kHz 0.5dB
Remains noise 0.3mV
Input sensitivity/impedance 1V/50kohm
<Preamplifier part>
Input sensitivity/impedance Phono: 2.5mV/50kohm
Mic: 2mV/50kohm
Aux, Tuner, Playback:150mV/50kohm
Output voltage Rec out:150mV
Pre out:1V
Frequency response Phono:RIAA}0.5dB
Aux: 20Hz-30kHz}0.5dB
Tone control Bass: }10dB (100Hz)
Treble: }10dB (10kHz)
High cut filter -6dB/oct(8kHz)
Equalizer allowable input 130mV(1kHz)
Equalizer input conversion noise -118dB
<Synthesis>
Power consumption 50W
Dimensions Width 380x height 133x depth of 301mm
Weight 7.7kg
Option Wood case CA-550 (5,500yen)