AKAI GX-93

Commentary

This cassette deck was developed with the aim of becoming a master deck compatible with digital sources, with a special emphasis on low-frequency recording and reproduction capabilities.

Newly developed New Super GX head is adopted for the head.
This head uses LC-OFC for the winding to reduce transmission distortion, which greatly improves resolution, especially for read heads with minute signal current levels.
The core material of the Super GX head is ferrite crystallized by AKAI's unique manufacturing method. It has characteristics such as high permeability, high magnetic saturation point, low residual magnetism and low magnetization resistance. The gap is set optimally at 4 μ m for the recording head and 1 μ m for the reproducing head. In addition, the in-line accuracy of both channels and the parallelism between the recording / reproducing head gap are maintained with high accuracy. This is a combination of AKAI's advanced processing technologies.

The mechanism uses a closed-loop double capstan system. In this system, the tape travel is strictly controlled by two capstan and pinch rollers, and the wow flutter is reduced by shutting out the disturbance from the reel. In addition, the tape span is short, the slight vibration of the tape can be controlled, and the tape tension is constant, so that stable head touch can be obtained.
To make the most of the advantages of the closed-loop double capstan system, the capstan shaft diameter is made different between the take-up side and the supply side. Moreover, by changing the diameter of the flywheel, the overlap of the rotation cycle is eliminated. In addition, the tape guide, which is generally placed on the side of the head, is placed separately. Moreover, the contact surface with the tape is made wide R surface, and the dual-wide tape guide with a unique structure is adopted. This solves many problems such as the handling of the dispersion of the cassette half, tape curl and track shift, uneven head touch, and meandering tape.
In the GX-93, the direct drive motor of the capstan adopts a quartz lock system, so that the rotation is hardly disturbed by load fluctuations and stable rotational characteristics are ensured.

The capstan shaft has a unique reverse electric hard chrome plating on the surface. By increasing the tape grip force, the slip phenomenon is almost 0. This treatment method has excellent abrasion resistance and maintains initial performance over a long period of time.

Silent mechanism is adopted, and when operation instruction is given, operation starts quietly.

In the power supply section, the signal system and microcomputer controlled mechanism system are separated from the power transformer winding to provide an independent power supply. In addition, the ground pattern of the microcomputer controlled circuit board is separated to prevent interference with the signal system to obtain clearer sound quality.
In addition, by separating the power supply for the amplifier circuit and the power supply for the noise reduction circuit and using ± 2 power supply configuration for each, we prevent non-linear signals during processor operation from causing interference with the amplifier circuit.

A unique twin active power supply is used in the read / write amplifier circuit to realize a very high-speed response, enabling a stable power supply. In addition, the twin active power supply realizes low-output impedance over a wide band, and response to low-frequency signals is also improved.

The recording amplifier section has a non-feedback push-pull configuration and a drive system with constant current drive.
This circuit greatly reduces the phase distortion in the high-frequency range, which was generated by the conventional V-I conversion by resistance, and improves the linearity in the high-frequency range.

The amplifier uses a direct-coupled input that eliminates the coupling capacitor between the head and the first stage of the amplifier. The amplifier uses a dual-op amplifier with high input impedance that consists of a low-noise J-FET for the input stage differential circuit, ensuring excellent characteristics of low noise and low distortion factor. In addition, the external phase compensation, combined with the effect of twin active power supply, realizes high slew rate and high stability operation.

Equipped with Dolby B/C NR and dbx NR as noise reduction systems.
The Dolby IC is equipped with a newly developed 3-head one chip encoding / decoding type that eliminates the deterioration of sound quality caused by characteristic errors that often occur with the conventional separate encoding / decoding type. The Dolby NR processor is also directly connected to the Dolby NR processor and consists of a DC amplifier.
The effect of dbx NR is to recover the dynamic range by recording the input signal with 1 / 2 logarithmic compression and expanding it twice during playback. The advantage of dbx NR is that the recording reference level does not need to be adjusted severely like the Dolby NR.

By using high-grade parts exclusively for audio, high sound quality is achieved.
The FBET (folded electrode transistor) is used from the amplifier to the power supply section. This transistor has a high speed by dividing the junction into multiple parts. It has a slew rate that is several times higher than that of the conventional type and improves resolution.
High-quality parts such as copper foil polypropylene capacitors, metalized polyester capacitors manufactured by West Germany ERO Co., Ltd., and mica capacitors are used for the capacitors for the compensation circuit of the amplifier system and the equalizer element.
All high-frequency cutoff and high-frequency compensation coils are made of LC-OFC with less transmission distortion to improve resolution in the high-frequency range. The core material is a low-distortion core used in low-pass filters for CD players.
The electrolytic capacitor uses a high-purity aluminum foil vibration-proof winding structure developed especially for audio equipment. This electrolytic capacitor uses a non-magnetic paint to prevent adverse magnetic effects.
High-precision metal film resistors are used in important parts such as the load resistor and compensation circuit of the amplification system, and the amplification gain and time constant are strictly controlled.

It is equipped with a manual bias control function that allows you to control the bias value within ± 20% according to your preference. If you shift the bias to a shallow level, the high-frequency range is enhanced. If you shift the bias to a deep level, you can create a rich sound in the mid-low range.
In addition to the master bias oscillation circuit for erasing, a dedicated Slave bias circuit for recording is grounded so that the recording bias can be freely changed without changing the erase current.

The display is equipped with a 3-way 4-digit electronic counter, 17-segment 2-color peak meter of -40dB to + 12 dB, and recording level guide indicator.

Equipped with a computer search function, it is possible to cancel a tune, perform an intro scan, and automatically start a single song before and after IPLS.

Equipped with direct lead-in and power eject functions for automatic loading.

Equipped with an auto tape selector, loaded tapes automatically detect the type of tape and set the bias equalizer value to match the tape.

Equipped with an auto monitor function, the monitor position is automatically switched to the source side when recording is on standby and to the tape side when recording is started.

The rigidity of the housing structure is measured, and a strong base plate is adopted, as well as a large foot which dumps external vibration.
In addition, the GX-93 has side plates to raise the design grade while increasing the overall body rigidity.

Equipped with Dolby B-C Type NR as a noise reduction system.

Equipped with an autoplay function that automatically starts playback after rewinding.

Equipped with an auto-mute mechanism that creates a 4-second space between songs.

Equipped with an output volume that can adjust the line output level and headphone level.

Equipped with a timer start mechanism.

Gold plated terminals are used for the line terminal and headphone terminal.

Uses a power cord with polarity display.

Equipped with an MPX filter that cuts the pilot signal that is mixed during air check.

The OFC connection code is included.

There are 2 color variations, black and champagne gold.

Model Rating

Type	Stereo cassette deck
Wow and flutter	0.025%WRMS(JIS) ± 0.04% W. Peak (EIAJ)
Frequency characteristic	20 Hz ~ 19 kHz ± 3 dB (Normal Tape) 20 Hz ~ 20 kHz ± 3 dB (Chrome Tape) 20 Hz ~ 21 kHz ± 3 dB (Metal Tape)
Signal-to-noise ratio (EIAJ)	59 dB (Metal Tape) Dolby B on : 5 dB improvement at 1 kHz, 10 dB improvement at 5 kHz or higher Dolby C on : 15 dB at 500 Hz, 20 dB at 1 kHz to 10 kHz
Distortion Factor (EIAJ)	0.5% (Metal Tape)
Dynamic range	With dbx NR system : 110 dB
Heads	Combination Head LC-OFC Super GX recording head LC-OFC Super GX Playhead 2 Erase Heads
Motor	For Capstan : Quartz PLLDD Motor For Reel : DC Motor Cam Drive : DC Motor
Input level	Line : 70mV/47k Ω
Output level	Line : 388mV/1k Ω Headphone : 1.3 mw (8 Ω) / 82 Ω
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	20W
Maximum external dimensions	Width 475x Height 112x Depth 353 mm
Weight	Approx. 7.3 kg
Attachment	Connection code x2