Audio Database

The

Aurex SY-77
138,000 yen(an age -- unknown)

Description
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The preamplifier which realized simple circuit composition which thought the characteristic and sound quality as important without adopting a tone jump system and spoiling a function.

By the tone jump system, it is considered as the simple composition which flies a tone amplifier circuit completely and connects an equalizer and flat amplifier at the time (at the time of Tone OFF), and it usually has the structure where tone amplifier is connected in Tone ON.

Few cut core transformers of a magnetic flux leak are adopted as a power-source part. And the cross talk characteristic is improved by forming winding wire independently for a right-and-left channel.
Moreover, he attains stabilization by preparing a constant voltage circuit for every circuit, and is trying to lower the impedance of a power source.
And }2 power-source system is adopted over a whole page.

Two steps of differential and a three-step direct connection active load Class-A circuit were adopted as equalizer amplifier, the high voltage of }70V was applied to it, and the allowable input of 600mVrms has been obtained.

Tone amplifier serves as a low distortion design which adopted one step of differential, and a two-step direct connection active load circuit.
The highly precise volume of an Attenuator form is adopted as control, and the exact change characteristic of a 2dB step is acquired.

The 2 steps of first rank cascade connection differential pure complimentary parallel push full circuit is adopted as flat amplifier, and the low distortion and the high dynamic range are realized in it with the composition which is equal to power amplifier.

The highly precise Attenuator type was adopted as the volume for volume control, and the exact change characteristic has been acquired.
Moreover, the Joint 4 form of one of the two's channel twin is arranged before and after flat amplifier, and the remains noise when having extracted volume is stopped.

Reed relay is prepared in order to remove the noise at the time of power-source ON/OFF for a Rec Out terminal and a Pre Out terminal.
The method of output short-circuit is adopted so that a signal may pass a relay and sound quality may not always deteriorate.

According to a cartridge, the change of load resistance and capacity is possible for Phono2.

It can mount on a JIS standard rack by option carrying handle TO-1 (3,000yen) carried with the photograph.

The data sheet by a computer (CADIS) is attached.

The

Rating of a mode
Form Stereo preamplifier
Circuit system Equalizer amplifier: Differential three-2 steps of step direct connection active load (Class-A)
Flat amplifier: 2 steps of differential pure complimentary parallel push pull (Class-A)
Tone amplifier: Differential two-step direct connection [ per step ] active load
Specification semiconductor Transistor x59, diode x42
Input sensitivity/impedance Phono1:20mV/47kohm
Phono2:47kohm<=>100kohm (20pF <=> 240pF)
Tuner, AUX, Tape1, 2:150mV/50kohm
An Output voltage/impedance
Tape Rec: 150mV/3.3kohm
Out Put: 1.0V/600 ohm (50kohm load, rating)
10V/600 ohm (50kohm load, maximum)
Phono maximum permissible input 600mV RMS(1kHz)
Phono RIAA Deflection }0.2dB (20Hz - 20000Hz)
THD
Phono: 0.012% (at the time of 1V output 1kHz)
0.004% (at the time of 3V output 1kHz)
0.002% (at the time of 10V output 1kHz)
AUX: 0.003% (at the time of 3V output 1kHz)
0.002% (at the time of 10V output 1kHz)
Frequency response (AUX) 10Hz-100000Hz+0dB-1.0dB
S/N ratio (IHFA network short-circuit)
Phono: 75dB
AUX: 90dB
Tone control
Bass: 20Hz}10dB (2dB step)
Treble: 50kHz}10dB (2dB step)
Subsonic Filter 10Hz, 12 dB/oct
Muting -26dB
Power source AC100V 50Hz/60Hz
AC outlet Switchedx2:400W
Unswitchedx1:400W
Power consumption 26W
Dimensions Width 450x height 93x depth of 379mm
Weight 9.5kg