AKAI GX-77

Commentary

This is a reverse recording re-open deck with EE tape support and Λ (lambda) loading for higher quality recording.

EE tapes are newly developed tapes using magnetic materials for high-density recording. They are conventionally used as video tapes and chrome tapes for cassette decks, boasting high coercive force and large residual magnetic flux density.
The GX-77 is equipped with a newly designed amplifier circuit, recording head, and erasing head in order to draw out the characteristics of this EE tape, and the high frequency characteristics are greatly improved by this EE tape support.

In order to maximize the characteristics of EE tape and to further expand the dynamic range, the constant of the reproduction equalizer in the EE position is set to 3180 + 35 at 19cm/s (3180 + 50 at LH position) and 3180 + 50 at 9.5cm/s (3180 + 90 at LH position). The noise level is reduced and the dynamic range is improved.
The basic compatibility characteristics of the EE position other than the equalizer and bias are in accordance with international standards such as IEC.

The mechanism part adopts a unique Λ loading in which the tape runs in the form of Λ, and there is no need to drag between tension arms and pinch rollers as in the past.
If you attach the tape and turn on the recording or playback switch, the center loading roller will be differential and set to the ideal running condition. In addition, since the Λ loading is symmetrical, uniform characteristics can be obtained in both directions.
Λ In the loading housing, the reciprocating 3-head system is arranged symmetrically to achieve uniform reciprocating characteristics. This structure eliminates the need to rotate or slide the head at the time of reverse and reduces the reverse time.
There is also a central loading roller that splits the tape path in two to improve performance, while also acting as a scrape filter to reduce modulation noise.

The head is equipped with a new GX head that is an improved version of the GX head with excellent dynamic characteristics.
By making the tip of the head core a compound R-shape, the contour effect has been thoroughly improved, and the waviness in the lower range has been eliminated. In addition, the shield between tracks has been strengthened, and low crosstalk has been successfully achieved.
In addition, a powerful double-gap erase head has been adopted for the erase head to obtain a sufficient erase rate even when EE tapes are used.

An FG servo DC motor is mounted to drive the capstan and a DC motor is mounted to drive the reel. Combined with a high-precision capstan with a special finish, the achieves stable travel in both round and round directions.
In addition, a tension servo is employed to keep the tape tension constant at all times, making the tape travel smoother and eliminating sound wamble.

The system is controlled by a microcomputer, a six head configuration with three reciprocating heads, and a three motor system with a double capstan drive to realize a 0.4 second quick reverse.

Equipped with a 3-stage switching reverse selector, it is possible to re-record one-way outward and return, re-record reciprocating outward and return, and endless playback.

It is equipped with a real-time electronic digital counter with minute and second display, a half-turn master volume considering usability, timer start mechanism for answering machine, queue / review mechanism, 2-color 16-segment LED bar meter with max hold, output volume and ± 30% variable bias adjustment volume.

Remote control operation is possible by the separately sold remote control unit.
The dust cover in the picture is sold separately.

Model Rating

Type	Reverse recording re-open deck
Track system	4-track 2-channel stereo system
Reel	Type 17 (No. 7)
Tape speed	19cm/s (± 0.8%), 9.5cm/s (± 1.0%)
Wow and flutter	0.03%Wrms(19cm/s) 0.04%Wrms(9.5cm/s)
Frequency characteristic (When using EE tape)	25 Hz ~ 33 kHz ± 3 dB (19cm/s) 25 Hz ~ 25 kHz ± 3 dB (9.5cm/s)
Distortion factor	0.5% or Less (1 kHz, Third Harmonic Distortion Factor)
Signal-to-noise ratio	65dB(19cm/s)
Heads	2 x GX Recording Heads 2 GX Playheads 2 Erase Heads
Motor	1 FG Servo DC Capstan Motor 2 DC Reel Motors
Fast-forward rewind time	Approximately 80 seconds (when using 360m tape on No. 7 reel)
Input level	Line : 70 mV
Output level	Line : 0.775 v Headphones : 1.3 mW
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	28W
External dimensions	Width 440x Height 244x Depth 227 mm
Weight	17.0kg
Attachment	Connection code x2 Empty Reel x1 One sensing tab
Sold Separately	Dust Cover DC-77 (¥ 6,500) Counter Memory Backup Adapter MP-515 (¥ 2,500) Remote Control Unit RC-21 (¥ 6,000)