AKAI GX-747

Commentary

This is a stereo tape deck developed as a system exceeding the GX 635 d in pursuit of sound quality.

Equipped with a tape selector, it is the first EE tape compatible in Akai.
The EE Position is a tape standard jointly developed by Akai, Maxell, TDK, and TEAC. Magnetic materials used in high-position cassette tapes and videotapes (Maxell : Epitaxial, TDK : Abilin) are newly used for open-reel. This makes it possible to significantly improve MOL characteristics and reduce noise levels in high-frequency ranges.
In order to draw out the characteristics of EE tape in the GX 747, the equalizer, driving system, head, etc. are designed for EE tape.

New GX head is adopted for the head part.
The New GX Head has better dynamic characteristics than metal heads such as SENDUST and Permalloy. The tip of the head core has a compound R shape to improve the contour effect and improve low-frequency playback. In addition, the shield between tracks has been strengthened to achieve low crosstalk.
In addition, it has excellent features such as abrasion resistance, dust resistance, and aging.

The erasing head has a double-gap design to support EE tapes with strong holding force.

The head configuration consists of six heads arranged in forward and reverse for recording, reproduction and erasing, respectively. Simultaneous monitoring is possible in both directions.

The capstan drive mechanism uses a CPG built-in AC servo motor that uses a sample-and-hold circuit with good servo characteristics similar to the GX 635 d. In addition, the capstan shaft of the GX 747 has AKAI's unique ultra-precision finish to improve abrasion resistance and tape gripping force.
It is a 3-motor DD system with separate dedicated motors for feeding and winding.

Symmetric tape travel mechanism is adopted for the tape travel mechanism.
In this system, three heads for the forward and three heads for the reverse are laid out symmetrically, and guide rollers are set on each of the left and right sides, so that the tape can travel stably with the optimum head touch in both directions.
In addition, the tension arm adopts an oil damper system, which reliably absorbs sudden tape vibration at the start, guarantees excellent start-up characteristics, and also has a protective mechanism for the tape.

The recording amplifier uses carefully selected high-quality elements, and the latest electronic circuit technology improves stability.

Newly developed auto-lock / release mechanism is adopted, and tape mounting can be done with one touch.
In addition, the special motor mounted on the tension arm automatically applies appropriate tension at the start of travel even if there is some slack in the tape and compensates for this.

The system control part is composed of a microcomputer, and it is a direct function change system which allows flexible position change by feather touch.

Memory reverse and immediate auto reverse play are made possible by the counter auto system equipped with a special microcomputer and the built-in Oatley Verse Recording / Replay Mechanism. In addition, one-way recording / replay, one round recording / replay and continuous playback can be automatically switched with one touch.
Manual reverse using conventional sensing tape is also possible.

The 10th open-reel is equipped with two microcomputers for the first time in the world, and it is equipped with various functions by extensive computerization.
The two microcomputers are for the system and for the counter auto system. The counter microcomputer processes the counter information transmitted from the system control microcomputer and sends it back to the system control microcomputer as control information.
These two microcomputers enable five automatic systems and are equipped with preset memory auto-reverse function, immediate memory auto-reverse function, lap counter function, count-up function, and auto 0 stop function.
The counter is an electronic digital counter that displays hours, minutes and seconds in real time, and can count up to 5 hours, 59 minutes and 59 seconds.

The preset memory auto-reverse function allows Oatley berth from any position by presetting the reverse point.
When recording, you can record back and forth continuously by setting the reverse point. When playing back, if you set the reverse selector continuously, Oatley verse is repeated between 0 : 00 : 00.

The quick-acting memory auto-reverse function enables Oatley birth at any position with one touch operation while the tape is running.
If the reverse selector is set continuously, memory auto-reverse playback between 0 : 00 : 00 and is possible.

The lap counter function can measure a specific program time during recording and playback separately from the tape counter set at the beginning. At this time, the counter set at the beginning also continues to operate. If the lap counter function is disabled, the normal tape counter will be displayed.

With the count-up function, both forward and reverse counts can be added and displayed during recording and playback.
Since the count can be added and displayed even if the tape direction is reversed during reciprocal recording and playback, calculation of program time, etc. can be performed easily.

The Auto 0 Stop function automatically stops the tape at 0 : 00 : 00 when the tape is being rewound or fast-forwarded in the count decrement direction. At this time, the tape stops while decelerating, so that there is no need to worry about damaging the tape.

Equipped with a memory backup adapter that can keep the counter in memory even if the power switch is turned off.

It is equipped with a cue / review mechanism that can fast-forward and rewind while playing.

Equipped with an auto mute mechanism that can automatically create a 4 second silent recording portion.

Equipped with a memory marker with friction stop convenient for fade-in / fade-out.

Equipped with a VU meter.

Equipped with timer start mechanism that can record absence.

Equipped with a bias adjuster that can be varied by ± 30%.

It is equipped with a pitch control that can change the tape speed during playback within ± 6% range.

Microphone and line mixing is possible.

Equipped with a recording mode selector to prevent accidental erasure.

Equipped with a reel size selector that can obtain an appropriate tape tension according to the reel size.

Equipped with an output volume that can adjust the headphone output.

There are 2 color variations of black and silver.

A separately sold remote control unit can be used.

Model Rating

Type	Tape deck
Track system	4-track 2-channel stereo system
Reel	Model 26 (No. 10)
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 tape for EE position)	25 Hz ~ 33 kHz ± 3 dB (19cm/s) 25 Hz ~ 25 kHz ± 3 dB (9.5cm/s)
Distortion factor	0.4% 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	One AC servo direct capstan motor 2 AC Eddy Current Reel Motors
Fast-forward rewind time	Approximately 75 seconds (when using 360m tape on No. 10 reel)
Input level	Microphone : 0.25 mv Line : 70 mV
Output level	Line : 0.775 v Headphones : 1.3 mW
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	80W
External dimensions	Width 440x Height 493x Depth 256 mm
Weight	23.2kg
Attachment	Connection code x2 Set Empty Reel x1 Sensing Tab Kit x1 Set Reel Hub Adapter x1 Set One AC adapter
Sold Separately	Wired Remote Controller RC-21 (¥ 6,000)