AKAI GX-270D
¥ 135,000 (released in 1975)
Commentary
A 3-head tape deck equipped with a recording GX / erasure combination head and two reproducing GX heads.
D-C-D (Direct Capstan Drive) is adopted for the mechanism part.
In this system, the shaft for feeding the tape and the shaft of the motor for exclusive use of the capstan are integrated. This makes it possible to specialize the motor for driving the capstan, reducing noise and eliminating the need for a cooling fan, improving quietness. In addition, since the rubber belt can be eliminated, the wow flutter can be kept low, and wear and deterioration of the rubber belt can be prevented. In addition, by simplifying the structure, error factors such as eccentricity and roundness can be reduced, and more accurate rotation can be obtained without being affected by fluctuations in the power supply.
The motor is composed of 3 motors.
For the reel, it is equipped with 2 Eddy Current Outer Rotor Type Motors for reel, and supports speedy operation and overuse.
The capstan motor is equipped with a C. P. G built-in pure-AC servo motor.
This motor uses a C. P. G detection mechanism. C. P. G stands for Center Pole Frequency Generator. It has a structure in which the magnetic pole of the detection part is in the center and a flux path (magnetic path) is formed radially. Since 112 pulses are added simultaneously over the circumference of the frequency generator, the detection output is large, S/N is good, and it is stable.
Since this frequency generator is built into the motor, eccentricity and eccentricity are minimized, and since it is not a rotating magnetic pole type as seen in other examples, there is no influence such as uneven magnetization.
The structure of this motor is an outer rotor type. The rotor is made of a high-quality electromagnetic steel plate processed into a cup shape. As a result, there is no change in magnetic resistance around the circumference, and very smooth rotation is obtained. Moreover, the moment of inertia is large and stable.
GX head is used for the head part.
The GX head provides 16-20 dB less compensation in the high-frequency range than the conventional head, enabling high-level recording on the same tape.
In addition, because of its ideal shape, the magnetic field is close to the focus state, making it possible to record more excellent sound.
Both auto and manual reverse playback is possible.
Sensing is a 1-point system. In order to take advantage of the D / C / D mechanism, the pinch roller is released from the capstan at the reverse point, and the capstan is clamped after the number of rotations becomes constant, so that the start-up is perfect.
The impedance roller has a shape similar to a double capstan and maintains stable tape running while applying a moment of inertia to the tape.
It is integrated with the flywheel inside, but it has a good balance design to take advantage of the start-up by the D / C / D mechanism.
It has an output volume.
The tape selector is a one touch type and can be set to the optimum values for the bias and equalizer.
The pose button reuses the lock style.
Equipped with a mixing mechanism of Line and Mic.
Equipped with a large VU meter.
It also has a peak level indicator that responds at plus 7 dB.
It adopts a new design using 3 mm thick aluminum.
Follow-up recording is possible.
Remote Control Unit RC-17 (sold separately) allows recording of absence.
Model Rating
Type | Tape deck |
Track system | 4-track 2-channel stereo system |
Maximum use reel | Model 17 (No. 7) |
Tape speed | 19cm/s, 9.5cm/s (± 0.5%) |
Wow flutter | 0.05%WRMS(19cm/s) |
Frequency characteristic | 30 Hz ~ 23 kHz ± 3 dB (19cm/s, AKAI LN-150-7 Tape Used) |
Distortion factor | 1% (1 kHz, 0 VU) |
Signal-to-noise ratio | 60dB |
Regenerative compensation characteristic | NAB |
Recording bias frequency | 100kHz |
Erasure rate | 70 dB or more |
Heads | Recording GX Head / Erasing Head x1 (Combo Type) Two recycled GX heads |
Motor | For Direct Capstan Drive : One C. P. G built-in pure AC servo motor For Reel : 2 x 6 Pole Eddy Current Outer Rotor Motors |
Fast-forward and rewind time | 75 seconds or less (when 370m tape is used) |
Input level | Mic : 2 systems, 0.3mV/-68dB (compatible impedance 600 Ω ~ 10k Ω) Line : 2 systems, 70mV/-21dB (input impedance 100k Ω) DIN : 1 system, 3 mv / input impedance 30k Ω |
Output level | Line : 2 systems, 0.775 V (at 0 VU) / optimum load impedance 10k Ω or more DIN : 1 system, 0.5 v at 0 VU Headphone : 1 system, 30mV/8 ohm |
Semiconductor used | Transistor : 52 Diode : 62 pcs |
Pwer | 100 VAC, 50Hz/60Hz |
Power consumption | 60/65W |
External dimensions | Width 440x Height 404x Depth 216 mm Width 441x Height 404x Depth 210 mm (listed in separate catalog) |
Weight | 15.6kg |
Sold Separately | Remote Controller RC-17 (¥ 9,000) |