¥ 148,000 (around 1979)
Stereo cassette deck for metal tape.
The mechanism uses a dual capstan system that uses two pairs of pinch rollers and capstan.
In this method, large windows on both the left and right sides of the cassette half are used for drives. Therefore, it was considered impossible to use a head that can handle metal tapes with strong hysteresis loops due to space considerations. To solve this problem, we developed a small erasing head for small windows in the TA-680.
The head uses a double-gap head that combines ferrite and Dynaloy with a Sendust core.
The Sendust Combination Head consists of a narrow head for playback and a wide head for recording.
The erase head is an FX ferrite junction metal compatible erase head.
In order to bring out the characteristics of the tape, it is equipped with auto accubias.
In this circuit, the outputs of two oscillators, a low-frequency (400 Hz) and a high-frequency (10 kHz), are mixed, recorded while changing the bias current, played back simultaneously taking advantage of the three heads, compared between the low-frequency and high-frequency levels of the reproduced signal, and the bias current is fixed when the two levels become equal.
During tuning, it can be confirmed by flashing green indicator.
The fade-out function allows you to fade out and erase unwanted parts of a recorded tape while playing it back. The fade-out circuit erases the recorded content while maintaining an appropriate time constant (approximately 3 seconds).
This circuit is also equipped with a safety mechanism to prevent accidental erasure.
In order to prevent the tape from becoming painful, if you press FF to REW continuously, the function will be switched to the next function via the STOP position. In addition, with the full auto-stop system, the mechanism will be surely free at the tape end, so that no excessive force is applied to the motor or tape.
Operability has been improved by adoption of feathertouch electromagnetic operation logic control circuit.
A PLL servo motor is used to drive the capstan of the drive section.
Equipped with a logarithmic compression type VU meter and 10-stage left / right independent peak indicators, memory play and rewind, timer recording and playback mechanism, equalizer / bias 3-stage independent switching, Dolby circuit with Rec level carriage, Rec Mute, microphone mixing circuit, microphone jack with automatic mode (stereo / mono) switching, headphone output terminal for high impedance, and soft eject mechanism.
|Type||Stereo cassette deck|
|Track format||4-track 2-channel stereo|
|Recording system||AC bias|
|Erasing method||AC Erase|
|Frequency characteristic||20 Hz ~ 20 kHz (Metal Tape)
20 Hz ~ 18 kHz (High Position Tape)
20 Hz ~ 16 kHz (Normal Tape)
|Signal-to-noise ratio||62 dB (Metal Tape)|
|Minimum input level||Microphone : 0.3mv/600 Ω
Line : 50 mV
|Input impedance||Microphone : 5k Ω (Compatible impedance 200 Ω ~ 50k Ω)
Line : 100k Ω
|Reference output||Line : 0.775 V (0 VU)|
|Load impedance||Line : 50k Ω or more
Stereo headphones : 8 Ω ~ 200 Ω
|Motor||For Capstan : PLL Servo DC Motor
For Reel Drive : DC Motor
|Heads||Recording : Sendust Combihead
Erasing : FX ferrite junction head
|Pwer||100 VAC, 50Hz/60Hz|
|External dimensions||Width 438x Height 160x Depth 365 mm|