CORAL A-550

Commentary

Pre-main amplifier with sound quality control circuit and head amplifier for MC.

In order to improve the sound quality of the transistor amplifier, which is said to be harder than a tube type amplifier, a unique sound quality control circuit is installed.

The Phono1 terminal is equipped with a high-sensitivity head amplifier, allowing MC type cartridges to be used without an input transformer.
The Phono2 terminal is for the MM type cartridge.

The main amplifier section is composed of silicon transistors, and uses an evolved color in which the first stage to the power stage are directly connected without loss parts.

Equipped with a purely electronic protection circuit using SCR, it protects the power transistor from damage accidents by operating when the output terminal is short-circuited.

Equipped with two speaker output jacks.

The preamplifier section and main amplifier section can be used independently.

It is equipped with a loudness control, high-cut and low-cut filters, a tape monitor, a headphone jack and a DIN connector.

The front panel uses aluminum drawn material that has been treated with alumite.
In addition, the wood case is made of Eurasian cheek material.

Model Rating

Type	Pre-main amplifier
Music power	50W (4 Ω)
Effective power	18W/18W (8 Ω)
Total harmonic distortion factor	Not more than 0.8%
Frequency characteristic	20 Hz to 40 kHz ± 2 dB
Output band characteristic	25 Hz to 40 kHz -3dB
Signal-to-noise ratio	Phono1:60dB Phono2:65dB Tuner, Aux : 70 dB
Residual noise	1mV
Input sensitivity (1 kHz at effective output)	Phono1:0.04mV Phono2:2.5mV Tuner, Aux : 200 mv
Damping factor	30 (8 Ω)
Loudness control (Volume-30dB)	100 Hz : + 7 dB, 10 kHz : + 6 dB
Tone control	Bass : ± 12 dB (100 Hz) Treble : ± 12 dB (10 kHz)
Low filter	50 Hz, -8dB
High filter	10 kHz, -8dB
Speaker impedance	4 Ω ~ 16 Ω
Semiconductor used	Transistor : 20 Diode : 7 pcs SCR : 1
Power supply voltage	AC100V/117V/220V/240V
External dimensions	Width 400x Height 146x Depth 278 mm
Weight	6kg