SONY EL-4
¥ 99,800 (around 1977)
Commentary
This is an L-cassette deck with improved usability by making maximum use of the auto mechanism.
Equipped with an automatic tape selector, the optimum bias value and equalizer are set automatically by the combination of the micro switch built into the compartment and the detection hole provided at the bottom of the cassette shell, and the indicator lamp lights up.
Automatic Dolby NR detection is possible.
When recording Dolby NR, it is automatically judged by folding the tab at the bottom of the shell of the L Cassette, and recording and playback are performed with Dolby NR On.
It is equipped with an MPX filter switch that cuts unnecessary pilot signal and subcarrier signal during air check to prevent malfunction of Dolby NR.
Rec-Mute can be performed by operating the lever.
It adopts a logical control system using a dedicated circuit and electromagnetic solenoid, and the operation lever can be operated with soft touch.
Continuous recording is possible by using the separately sold program timer.
The head uses a solid-core all-ferrite F & F head that uses a single non-layered ferrite plate not only for the core part but also for the guard part. As a result, the phase and frequency characteristics are improved with less possibility of offset or gap deviation.
We have also improved the S / N ratio, frequency characteristics, and distortion factor by adopting a direct coupling method that directly connects the F & F head and the reproducing amplifier using FET.
The motor is equipped with a frequency servo motor with FG.
Servocontrol is performed by directly connecting an FG (frequency-generator) to the rotating shaft of the motor and detecting the rotational speed deviation based on the generated frequency change. This structure makes it less susceptible to electrical fluctuations in the circuit. Even if the voltage fluctuates due to temperature rises, the oscillation frequency hardly changes and the rotational speed remains stable.
Equipped with a tension regulator that suppresses speed deviation when the tape is running.
It is equipped with a scrape filter to suppress modulation noise.
Follow-up recording is possible.
Equipped with a memory stop mechanism.
Equipped with an input selector.
Equipped with photoelectric detection type auto shut-off mechanism.
Equipped with safety lock mechanism.
Equipped with a soft eject mechanism.
Model Rating
| Type | El Cassette Deck |
| Heads | Erase : 1 Recording : 1 |
| Motor | Frequency servo motor with FG x1 |
| Signal-to-noise ratio | 62 dB (dolby off, peak level, Type-II duad) |
| Frequency characteristic | 25 Hz ~ 20 kHz ± 3 dB (Type-II Duad) |
| Wow and flutter | 0.06% |
| Distortion factor | 0.8% (Type-II Duad) |
| Power consumption | 25W |
| External dimensions | Width 430x Height 170x Depth 320 mm |
| Weight | 10.3kg |