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Akai GX-630D

Three Head Stereo Tape Deck (1976-79)

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Akai GX-630D


As is well known, the core of Akai's GX Head is made of crystal ferrite and is mounted and set in glass. The superior magnetic properties of the head material and special processing allowed the formation of a perfectly lineal shallow head gap, an acute head surface angle contour, and focusing of the magnetic field into a sharp oblong radius.

This focused field system eliminates undue equalization, minimizes high frequency loss, and achieves a wider dynamic range.

Further, sound drop-out is eliminated, head to tape contact and signal to noise ratio improved, and the hardness of the head materials provide dust free and wear free characteristics for longer lasting performance. The GX-630D exhibits a clear frequency response range to 25,000 Hz with Akai LN-150-7 tape.

This model employs a 3 motor drive system with a new CPG (centre pole generated) AC Servo Motor for direct capstan drive. The quality of this outstanding motor plus the elimination of rubber belts and flywheels results in the realization of a 0.06% Wow and Flutter factor.

Two eddy current outer rotor motors complete the drive system for completely stable performance and excellent tone quality. Impedance Roller and Tension Levers also add to tape travel stability.

A Reel Size Selector and standard accessory 10-1/2" reel hub adapters facilitate the use of 5, 7, or 10-1/2" reels.

Further, this model features quick tension wherein ideal take up and back tension is applied to the reels at the beginning of tape start for smooth operation regardless of reel size.


Track system: 4-track, 2-channel, stereo/monaural system

Heads: 1 x playback, 1 x record, 1 x erase

Motor: 2 x reel drive, 1 x capstan

Reel size: up to 10.5 inch reel

Tape speeds: 3 34  7 12 ips

Wow and flutter: 0.06% (7 12 ips)

Frequency response: 30Hz to 25kHz (7 12 ips)

Signal to Noise Ratio: 57dB

Total harmonic distortion: 0.5%

Input: 70mV (line), 2.5mV (DIN), 0.25mV (mic)

Output: 0.775V (line), 30V (DIN)

Semiconductors: 50 x transistors, 57 x diodes

Dimensions: 465 x 440 x 240mm

Weight: 19kg

Accessories: connection cords, reel hub adaptors, empty reel


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Reviewed Feb 22nd, 2019 by Randschmidt

Found it at my local thrift store for a hundred bucks with cover. I was auditioning it and I couldn’t get the vu meters to respond when the output knob was increased or deceased thought it had an issue so they took 20 bucks off the price. Well that’s how it is designed output knob increased vu meter stay the same I have pioneer RT707 /909 almost all of the Akai 4000 series And one Teac I must like this one because it’s in the living room and the wife doesn’t complain. Pro’s for me direct drive no belts glass head don’t think it will ever wear out in my life time sounds as good as my Pioneers or Teac what I don’t like is no reverse directional mode must turn the tape over both my Pioneers and my Teac have that feature and it has spoiled me over the years. If I was going to buy one 10 inch reel machine it would be this ones for glass heads and direct drive.

Reviewed Dec 25th, 2018 by NICHOLAS REYNOLDS

Probably, the best tape recorder our days. Very,very reliable. Eternal hi quality gx heads. Direct drive , no capstan belt. Low detonation, fantastic sound quality. Bought in 1978. Still working!

Reviewed May 25th, 2018 by vladimirescu

Great machine. Reliable and easy to maintain. But the sound isn't best than GX 4000. NR dolby is not justified for this technology. For AKAI's open reel machines, the only advantage of comon 26,5 cm recorders, from 630 to 635, is the duration of the play. Otherway the sound is comparabile to all 18 cm recorders.

Reviewed Mar 21st, 2018 by iso14000

hi, great ! I bough my one this afternoon to backup several tapes to digital machine.
schematics are very clear! surprisingly no IC for amp/oscillator even for closed loop speed control.....
I'll probably mod the latter to a digital PLL .... I'm an electronics

best regards!

Reviewed Feb 28th, 2018 by N REYNOLDS

Just bought gx-630d , lightly used, better sound vs gx4000, imho. Great machine
The only problem, when the heads will be worn, how and where to get a replacement heads? Nothing on eBay at all...

Reviewed Dec 01st, 2015 by Kajtsu

I bought mine few years ago. I have always wanted one. Excellent sound. It´s regrettable that reel to reel tapes are not made today and prices go higher. Mine is DB (dolby) version but dolby is not needed. I don´t use it at all.

Reviewed Mar 05th, 2015 by Cristiano90

This is a simple and great tape recorder. Looks awesome and it is easy to be maintained. By replacing 2SC458 transistors inside with a new ones, will reduce the noise of the amplifier.



re: GX-630D

Thank you for letting me download the manuals.
Just bought this off from a friend who had it unused. Now I got a project through out winter :)
From what I have read, other postings, the say that this is a good example of a reel to reel device. Cant wait.

Once again thanks to all contributors

re: GX-630D

Thank you very much for the dl's. This beauty has been sitting idle for almost thirty years. It was used in a recording studio of a radio station in New York. And, I am finally getting it hooked up to my computer to digitize about two-hundred tapes.


Thank you so much for the manual downloads. Keep up the good work. I really appreciate it sincerely.


GX 630 D PRO 2 track

Looking for an owners manual + service manual for a GX 630 D/PRO
Thanks in advance,


service manual and schematic wanted Akai GX-630D

service manual and schematic wanted Akai GX-630D

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