CORAL TA-7700
Price unknown (around 1967)
Commentary
Stereo receiver using IC and FET.
It uses a SEPP-ITL-OTL circuit that does not use an input transformer or an output transformer. It also uses a diffused silicon power transistor to achieve high output.
All signal circuits are composed of silicon transistors to realize broadband characteristics.
In order to solve the problem of the transistor amplifier, which is said to have a harder sound than the tube type amplifier, the tone quality control circuit developed in-house is mounted.
The Phono1 terminal has a built-in head amplifier to increase sensitivity, and MC type cartridges can be connected without an input transformer.
The Phono2 terminal is compatible with MM type cartridges.
It is equipped with a pure electronic protection circuit by adopting SCR.
This circuit operates when the output terminal is short-circuited and protects the power transistor from damage accidents.
Two types of speakers can be connected.
It uses a loudness control, tape monitor, high-cut and low-cut filters, headphone jack and DIN connector.
The IF section of the FM tuner consists of five stages, and the reliability and characteristics are improved by adopting IC.
By using FET in the RF circuit, intermodulation distortion is greatly improved.
To prevent interference between SCA and FM broadcasts, an SCA filter with an attenuation of 50 dB or more is installed.
A muting switch is mounted to reduce inter-station noise during FM tuning and detuning.
It is equipped with an AGC (Automatic Gain Control) circuit to prevent distortion of sound by a strong electric field that receives strong radio waves from the antenna.
Silicon diodes are used in the MPX circuit to reduce the effect of ambient temperature changes on the separation.
Equipped with FM mono-stereo automatic switching circuit.
The FM stereo display lamp lights up during stereo broadcast transmission, and a malfunction prevention circuit is built in to prevent lighting due to external noise.
It is designed with extruded aluminum material.
There was a wood case sold separately.
Model Rating
Type | FM/AM Receiver |
Amplifier Unit | |
Music power | 160W (8 Ω) |
Effective power | 50W/50W (8 Ω) |
Total harmonic distortion factor | Not more than 0.8% |
Frequency characteristic | 20 Hz to 40 kHz ± 2 dB |
Output band characteristic | 20 Hz to 20 kHz -3dB |
Signal-to-noise ratio | Phono1:60dB Phono2:65dB Aux:70dB |
Input sensitivity | Phono1:0.04mV Phono2:2.5mV Aux:200mV |
Damping factor | 30 (8 Ω) |
Loudness control (Volume-30dB) | 100 Hz : + 6 dB, 10 kHz : + 3 dB |
Tone control | Bass : ± 10 dB (100 Hz) Treble : ± 8 dB (10 kHz) |
Low filter | 50 Hz, -8dB |
High filter | 15 kHz, -8dB |
Speaker impedance | 4 Ω ~ 16 Ω |
FM Tuner Section | |
Sensitivity | 2 μ V (IHF) |
Image ratio | 65dB |
Frequency characteristic | 20 Hz to 20 kHz ± 2 dB |
Total harmonic distortion factor | 0.7% or less (1 kHz, 100% modulation) |
Signal-to-noise ratio | 60dB |
Stereo separation | 40dB |
<AM Tuner Section> | |
Sensitivity | 20 μ V (IHF) |
Image ratio | 50dB |
<General> | |
Semiconductor used | Transistor : 42 Diode : 27 units Thermistor : 4 pcs Pooster : 2 pcs SCR : 1 |
Power supply voltage | AC100V/117V/220V/240V |
Power consumption | 45W (no signal) 350W at maximum output |
External dimensions | Width 475x Height 150x Depth 420 mm |
Weight | 12.5kg |
Sold Separately | Wood case |