Technical Details
Brand: Akai
Model:GX-747
Category:Super High Fidelity
Application:Consumer
Electronics:Solid State
Equalization:NAB
Country of Manufacture:Japan
Release dates:1981 - 1985
Original Price: $1300
Tracks:1/4 Rec/PB
Speeds: 3 3/4, 7 1/2
Max Reel Size("): 10.5"
Number of heads: 6
Dimension: 17½ x 19 x 10" (440 x 483 x 256mm)
Head Composition: Permalloy, Ferrite/Glass
Head Configuration: Stereo
# Motors: 3
Auto Reverse?:Yes
Voltage(s): 110-120v, 220-240v
Outputs: RCA
Frequency Response:25Hz to 33kHz @ 7.5ips
Wow and Flutter:less than 0.03% WRMS at 7½ ips, less than 0.04% WRMS at 3¾ ips
Signal-to-Noise Ratio:better than 65dB at 7½ ips (DIN 45 500)
Sound quality rating:7 / 10
Long-term reliability rating: 8/ 10
Weight: 46.4lbs (21kg)
Additional Details
Description
Many people believe that the Akai GX-747 and its successor the GX-747dbX were the finest reel-to-reel decks ever produced by Akai, or any one else for that matter (others insist it was Akai’s Pro 1000). It was extremely well made and utilized the evolving technology of its predecessors.
Superficially, the GX-747 looks like an advanced version of the GX-646, with all of the functions of the latter and then some. As it was a 4 track machine, it did not feature 15 IPS which many of the competition could offer at the time.
The function panel was the same as the one used on the GX-77 with the addition of an auto-mute button – (4 seconds, non-adjustable). A drop-down cover revealed the control panel which was almost identical to that of the GX-646. The GX-747 was loaded with many features, some of which are listed below.
EE Tape Compatibility – the advent of high performance Extra Efficiency (EE) tapes rendered older reel-to-reel systems obsolete. New circuitry was required in order to reap the full benefits that EE tapes delivered and because of Akai’s involvement in the creation of EE technology, they were able to design optimal, advanced circuitry to fully maximize the amazing qualities of EE. The sonic performance was truly remarkable with much better output, broader dynamic range, wider frequency response and an absolute minimum of distortion.
It featured six heads, four of them being of the Akai GX (glass-crystal) type – one each for forward record, forward playback, reverse record and reverse playback. The heads were arranged along with the two erase heads in the head block in perfect symmetry, resulting in an accurate, stable tape path with absolutely no contact error.
Three independent motors drove the capstan, supply reel and take-up reel. The extremely stable AC servo capstan motor maintained perfect speed at all times, while keeping wow & flutter to a negligible level. Motorized tension arms made tape threading easy. During fast forward or rewind, they automatically sensed and corrected for tape slack or potential snagging; and at the end of the tape, they opened automatically to facilitate tape loading.
Feather-touch, microcomputer controls allowed effortless transport operation. Tape travel direction was verified by a lighted indicator. Direct mode changes between any two transport functions were possible so that one could jump quickly from one to the other without fear of damage to the tape or transport.
The auto reverse feature operated at end-of-tape or at a preset reverse point in either playback or record. The Reverse Selector switch gave the option of one-way or two-way recording or playback, or continuous playback.
A sophisticated memory/timing control system (displayed in ‘real time’) enabled the recorder to run continuously for up to six hours in either record or play back. A secondary “lap” counter allowed the user to measure isolated sections on the tape without losing the overall position. With the Memory Reverse function, the tape could reverse at a pre-selected position and play back to the zero position. The reverse point could be preset to the current position, or to any other position (time) on the tape. Memory Rewind would automatically bring the tape back to any preset zero position.
A bright, 24-segment LED bar graph with 1 second peak hold made record level monitoring extremely easy.
Akai produced 5 variations of the 747, silver and black with the following options depending on the time of production- VU or LED meters and DBX.
Additional Info
Frequency response
7½ ips: 25Hz to 33kHz +-3dB (EE tape)
3¾ ips: 25Hz to 26kHz +-3dB (EE tape)
Pitch control more than ±6%
Dimensions: 17½ x 19 x 10″ (440 x 483 x 256mm)
Weight: 46.4lbs (21kg)
Rewind speed: 75 seconds for 1200ft
Distortion: less than 0.4% at 7½ ips
Inputs: mic: 0.35mV impedance 600 ohms, line: 70mV 100 ohms DIN: 2 mV 10K
Outputs: line: .775V at 0 VU – required load impedance more than 20K DIN: 0.3V, required load impedance 10K
Headphones: 1.3mV 8 ohms /