AKAI GX-R88
¥ 118,000 (released in 1983)
Commentary
A quick reverse deck incorporating GX-R99 technology.
The Super GX head is used independently for recording and playback, and the Accurate Reverse Head System, which rotates the head block 180 degrees, is used for reciprocal recording and playback.
The Accurate Reverse Head System uses a high-hardness zinc die-cast containing beryllium as the head housing material in order to maintain a high precision position of the head with respect to the tape. This material is twice as hard as conventional zinc die-cast and eight times more wear-resistant. Precision processing with a tolerance of several microns ensures high precision.
The rotating parts are coated with a solid lubricant mainly made of a highly slippery fluorinated resin using precision coating film control technology to a thickness of several microns. The friction coefficient has been greatly reduced and durability has been achieved over 2 million times continuously. In addition, in order to maintain accurate azimuth in both directions, high-hardness fine ceramics (alumina with over 99% purity) is adopted on both sides of the stopper part, and impact caused by rapid rotation of the head is 1,000kg/cm.222,000kg/cm2It has sufficient strength to ensure long-term wear resistance and impact resistance.
The azimuth adjustment screw that catches the stopper uses a fine screw that is hardened stainless steel. It reduces wear by making hardness and cushioning compatible, and the elasticity of the stainless steel inside absorbs impact. In addition, the loosening of the adjustment screw, which is a problem in long-term use, is dealt with by the double nut system, and the looseness is securely locked by tightening with double nuts.
In addition, a roll-up flexible printed board with lead wires printed on thin and tough polyamide resin has been adopted. Since the rotating part is wound spirally, rotational load torque is not applied to the head, and troubles caused by curing at low temperatures are also prevented.
As for the rotation of the head, it is a double pinion drive in which the rack with especially low friction coefficient is quickly shifted left and right by the motor drive, realizing an extremely simple rotation mechanism.
The Super GX Head is a ferrite head that succeeded in making low-noise crystals by our original processing technology. This ferrite head is used for the head core and shield core, and the whole structure is hardened with high-hardness glass.
This head solves the drawbacks of conventional ferrite heads, such as noise and particle loss, and realizes high permeability and wide frequency characteristics with very little eddy current loss in the high frequency range. It also has advantages such as extremely high machining accuracy of head gap.
In the GX-R88, the Super GX head is used exclusively for recording and reproduction. It is a combination type 3-head system with high precision integration. The gap of the recording head is 4 microns wide to prevent magnetic saturation even when a deep bias current is applied, and the gap of the reproducing head is 1 micron wide to extend the frequency characteristics to 20 kHz or more.
In addition to the closed-loop double capstan mechanism, AKAI's unique bi-directional symmetrical precision -directional symmetrical precision (BSP) mechanism is adopted to achieve uniform round-trip driving characteristics.
In the closed-loop double capstan system, the tape near the head is sandwiched between two sets of capstan and pinch rollers to give a certain tension to the tape. In this system, disturbance from the reel can be shut out, thus improving the wow and flutter characteristics. Moreover, by shortening the tape span, minute vibration of the tape during running is controlled. In addition, constant tape tension can be obtained from the beginning to the end of the tape winding, thus stabilizing the head touch.
In the GX-R88, the capstan diameter on the take-up side is slightly changed to 2.3 mm and the capstan diameter on the supply side is slightly changed to 2.5 mm in order to maximize the advantages of the closed-loop double capstan system. This prevents the occurrence of wow due to overlapping rotational periods. In addition, the pressure force of the pinch roller to the capstan shaft is adjusted to be low on the upstream side and high on the downstream side in the tape running direction, so that the stability of tension in the loop is improved.
In order to achieve excellent tape travel in both forward and reverse directions, we have adopted a direct drive system for both.
The DD motor uses a brushless, coreless, and slotless FG servo system with sufficient flywheel thickness to increase the moment of inertia, thereby achieving extremely high rotational accuracy.
The Twin DD system is driven by a motor on the take-up side and driven by a belt on the supply side. At the time of reverse, the FG servo is temporarily released, and reverse voltage is instantaneously applied to the two motors to realize a quick reverse. In addition, to quickly stabilize the tension in the loop, the timing at which the pinch roller is pressed against the capstan is controlled early on the downstream side of the tape and late on the upstream side.
In order to achieve uniform round-trip travel characteristics, we have adopted the BSP mechanism with symmetric tape transport, so that the travel characteristics in the forward direction can be reproduced in the reverse direction as well.
In addition, we have adopted a dual-wide tape guide system in order to eliminate the factors that change the running characteristics hidden in the cassette half itself. In this system, the tape guide is separated and independent from the recording / reproducing head, and the contact surface with the tape is kept wide enough to hold the tape. In addition, the height of the guide is adjusted with a high precision of 0.01 mm in order to always maintain accurate azimuth. This eliminates tape deflection near the recording / reproducing head, uneven crimping, tape edge curl, etc.
Equipped with quick auto-tuning system.
By simply pressing the REC/PAUSE button when loading a tape and moving to recording, this system quickly sets the optimum recording conditions for the tape. The tuning time is approximately two seconds, ensuring high accuracy and quick operation.
The main amplifier is a DC amplifier with excellent phase characteristics and dynamic range, and the special input part is a direct input without a coupling capacitor to reduce sound quality degradation.
In addition, the entire circuit configuration uses simple straight construction to eliminate mutual interference caused by crossing signal paths.
The playback equalizer amplifier uses a high-performance dual FET and dual transistor with a two stage differential + A-class SEPP circuit. The discrete configuration pursues quality. Dual FET and dual transistor are two FETs and transistors with the same characteristics in one package. They have high thermal balance and little variation in operation, so they can shut out noise and fluctuation from power line and ground line.
The EQ amplifier is directly coupled to the Super GX playhead to prevent degradation of sound quality caused by coupling capacitors. In addition, 99.99% pure oxygen-free copper wire is used for the lead wire from the head.
High-quality devices, including custom-made products, are introduced everywhere to improve audible sound quality that does not appear in specifications.
The newly developed FBET (Fold Back Electrode Transistor) is used in the signal amplification control circuit. This device is a finely divided structure inside a conventional chip-size transistor. It prevents the local concentration of current that occurs when a large high-frequency current flows instantaneously. As a result, high speed is achieved and the slew rate is several times higher than that of conventional devices.
The line amplifier is also equipped with a high-speed Bi-FET. The Bi-FET is a complete DC amplifier with a FET differential input circuit. It has a very high slew rate and a high stability and wide dynamic range with a particularly low noise level.
A newly designed high-speed tracking regulator is used in the power supply section, and uniform power supply current can be obtained by applying feedback on the + side and - side respectively with respect to the + side power supply as a reference. This ensures stable amplifier operation.
In order to eliminate mutual interference between the Dolby block and the amplifier block, the Dolby block is made independent of the amplifier block. In particular, the power supply part is completely independent so that the line amplifier is not affected by the DC nonlinear signal that flows in the control circuit of the Dolby level detection. In addition, the Dolby IC uses the latest standard IC, which improves sound quality compared IC.
In addition, we have adopted a double-process system using a Dolby IC for encoding and decoding.
Equipped with a REC cancel mechanism, it can rewind to the beginning of the mistake recording with one touch, mute recording for about 4 seconds, and then it becomes recording standby.
It is equipped with a blank search system, which searches for an unrecorded portion of more than 3 minutes, rewinds to the end point of the previous song, creates a blank portion of approximately 7 seconds, and stops. If there is no blank on the A side, the search continues on the B side.
Equipped with an intro scan, you can skip the intro of recorded songs for 10 seconds at a time with one touch.
Equipped with IPLS (Automatic Head-Out) mechanism, it is possible to head-out one song before and after.
Equipped with QMSS (quick memory search system), it fast-forwards to the counter 0000 position at the shortest distance regardless of the tape running direction and starts auto-play in the direction mode at the time of 0 reset.
It is equipped with an auto-fader. When the switch is pressed during recording standby, it fades in up to 7 seconds to the recording level, and when it is pressed during recording, it fades out in about 5 seconds.
Equipped with an auto monitor function, it monitors the source side during recording standby and switches to a tape monitor as soon as recording starts.
Equipped with auto-mute mechanism, a space of approximately 4 seconds can be created with one touch.
Equipped with an auto tape selector, it can automatically detect the type of tape and set the bias and equalizer to the Akai reference values.
A large FL concentrated display is used in the display section.
The display includes a 3-way 4-digit electronic counter, 3-way 2-color 24-segment FL bar meter, and other control information.
Equipped with a direct lead-in mechanism, it can be loaded automatically by simply setting it in the cassette half in the ejected state and pressing the operation button. Also equipped with a power eject system, pressing the EJECT button cancels all operations and the motor drive ejects it.
Quick & quiet mechanism is adopted, and quick and quiet operation is realized by setting each mode in combination with exclusive cam motor and cam controlled by microcomputer.
Equipped with Dolby B Type and Dolby C Type as noise reduction system.
Equipped with an Output volume that allows you to adjust the output level and headphone level.
The input / output terminals are gold-plated.
Equipped with an MPX filter switch.
Equipped with a reverse mode selector.
Equipped with a timer start mechanism.
There are 2 color variations of black and silver.
It can be operated from a remote location by connecting the separately sold remote controller.
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Model Rating
| Type | Stereo cassette deck |
| Wow and flutter | 0.028%WRMS(JIS) ± 0.055% W. Peak (EIAJ) |
| Frequency characteristic | 20 Hz ~ 18 kHz ± 3 dB (Normal Tape) 20 Hz ~ 19 kHz ± 3 dB (CrO2 Tape) 20 Hz ~ 21 kHz ± 3 dB (Metal Tape) |
| S / N ratio (metal tape) | 56dB(EIAJ) 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 (1 kHz, 0 VU) | 0.5% (Metal Tape) |
| Heads | Combination Head Super GX recording head Super GX Playback Head 2 Erase Heads |
| Motor | For Capstan : FG Servo DD Motor x2 For Reel : DC Motor Mechanical Drive : DC Motor |
| Quick winding time | Approximately 90 seconds (when C-60 tape is used) |
| Input level | Line : 70mV/47k Ω |
| Output level | Line : 410mV/2k Ω or less Headphone : 1.3mW/8 ohm |
| Power supply voltage | 100 VAC, 50Hz/60Hz |
| Power consumption | 34W |
| Maximum external dimensions | Width 440x Height 105x Depth 372 mm |
| Weight | Approx. 7.6 kg |
| Attachment | Connection code x2 |
| Sold Separately | Wireless Remote Control RC-92 (¥ 18,000) Wired Remote Control RC-32 (¥ 6,000) |