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Akai GX-4000D Reel-to-Reel

Article from Home & Studio Recording, October 1984

The GX-4000D represents the Akai Electric Company's re-introduction of this famous machine. Previously known as the 4000DS and sold throughout the early 1970s, the original model was an unpretentious tape recorder that provided many people with their first taste of recording but, unfortunately, the machine was withdrawn from the market.

Now after an absence of some years, Akai have responded to the growing interest in home recording by re-introducing the new machine as the GX-4000D. Paul Gilby assesses the revitalised recorder.

The GX-4000D is a dual speed ¼ track tape recorder using ¼ inch tape with a maximum spool size of 7 inches. Being a ¼ track machine, it allows you to record up to four individual tracks of sound in one of two formats, either two stereo recordings, one in each tape direction; or four mono recordings, two in each direction at either the higher operating speed of 7½ ips or at the low speed of 3¾ ips.

With a combination of these track formats and tape speeds owners of this machine have the best of both worlds - tape economy and recording quality packaged in a tape recorder which retails at a very competitive price.


All the usual transport controls are included but are perhaps a little unconventionally laid out by today's designs. Split across two large mechanical levers, the play and record functions are selected by switching the left hand lever, and the fast rewind/forward functions controlled by the right hand lever. The pause function is selected by pushing up a small lever in the direction of the arrow, and is cancelled by pressing the pause defeat button immediately below it. The all important record function is selected by first depressing the record button and switching the master left hand lever into the record position, whereupon a small red LED mounted between the two VU meters is illuminated. An auto stop feature is included and this operates by threading the tape around the tape tension arm near to the capstan so that when the tape comes to an end the arm falls downwards and switches off the motor.

One of the most welcome improvements over the old machine is the ability to remove the head cover which now makes the three heads totally accessible for cleaning and demagnetizing, a very difficult task indeed on the old 4000DS. The same improvement, however, is not true of the tape speed selection. This is still achieved by a somewhat strange method for those who have never encountered the 4000DS before.

With the machine switched off you have to unscrew a knurled nut and remove a small metal collar from the capstan, without the collar the machine runs at 3¾ ips and with it in position the tape runs at 7½ ips. If the collar has to be removed it can be stored on a post situated under the head cover for safe keeping (see Figure 1).

Figure 1 Headblock.

To conclude the change of tape speed, you have to select the appropriate EQ setting relative to the tape speed and this is done via a front panel switch labelled with the two alternative tape speeds. This method of speed change is by today's standards of electronic switching and logic control rather clumsy and shows up the fact that the GX-4000D is actually a fairly old design.

If there is one feature of the original 4000DS that I thought Akai would have changed it is the method by which you selected the tape speed. However, this has not materialised probably because it is an inherent part of the mechanical design of the machine and not easily changed. Having said that, changing speeds is not actually difficult once you're familiar with the routine, but I still can't help thinking that one day somebody's going to lose their capstan collar and nut and be stuck with the machine permanently running at 3¾ ips. Address of Akai's spares department to follow!

The last point to mention is the tape counter which is of the mechanical toothed wheel type, driven by a rubber band from the motor. It performs adequately, though, yet again, it's somewhat basic by today's standards of digital LED readouts. Well that ties up the mechanical side of the machine, so let's look at the electronics.


Four inputs in total are provided, these being two microphone inputs of the ¼ inch jack socket type, mounted on the front panel with their related level controls located immediately to the left. Two line level inputs on phono connectors situated on the rear panel are also provided. Level controls are again found on the front panel and as with the mic input levels both sets of controls are of the concentric type, which make for easy track fade-outs during recording.

All signal levels are monitored visually on the two VU meters (0VU = 0.775 volts) and aurally via the stereo headphone output. Situated between the meters and input level controls are four pushbuttons labelled from left to right: Monitor, this simply selects either the 'source' or 'off tape' signal for monitoring at the output. SOS (Sound on Sound), which is used for the automatic transfer of one track to another, explained in detail later. EQ, selected to correspond to the correct tape speed. Finally, the Tape Selector which is used for matching the tape you are using to the machine's bias electronics, the options being 'low noise' for all general purpose tapes and 'wide range' for high output tapes.

Track Selecting

As previously mentioned the GX-4000D will allow you to record in either mono or stereo. For stereo recording, the track select switch is first set to the stereo position, the left and right input levels are adjusted and a recording is made. This first recording takes place on tracks 1 and 3. When the whole tape has been used it can be turned over and a further stereo recording can be made, this time on tracks 2 and 4 (Figure 2a).

Figure 2a Stereo operation.

When mono recording is required up to four separate tracks can be recorded. First, place the track selector switch in the 1—4 position, connect a signal to the left input and adjust the level, the recording will now appear on the left track (1). Rewind the tape, set the track selector to 3-2 and plug your signal into the right input channel, adjust the level and make a second recording.

You now have two mono recordings, one on track 1 and another on track 3. By turning the tape over two further recordings can be made in a similar manner except this time you will be recording onto tracks 4 and 2; again the track selector switch is used for this purpose. This gives a total of four individual tracks, two in each direction (Figure 2b).

Figure 2b Mono operation.

Sound on Sound is, as the name suggests, a feature which allows you to superimpose one sound onto another and have the end result recorded on one single track. For those people interested in multi track recording, this is perhaps the most exciting feature on the machine and adds real versatility to this humble tape recorder.

The operation of the SOS feature is quite straightforward requiring not even the merest hint of Morse Code! Start by making a mono recording on track 1 as previously described. Place the SOS switch in the 'on' position and set the track selector to 3-2. Turn up the right channel line input level to almost maximum and then connect another signal source to the right channel mic input and set the signal to the required level. When a recording is made, you will transfer the original recording made on track 1 and mix it together with the new sound coming in on the right channel; both sounds will now appear on track 3. This SOS operation, which is more usually known as track bouncing, can be carried out many times allowing you to build up several layers of sound without too much tape hiss - and all in perfect synchronisation and without unplugging any leads.

The GX-4000D provides two signal outputs, one via a pair of phono sockets labelled left and right, and a second via a five pin DIN socket. This will actually allow you to both record and playback using the one cable which would normally be connected to a corresponding socket on the back of your Hi-Fi amplifier.

In operation you will find that the phono sockets actually provide the best option if creative work, ie. track bouncing and echo effects, are required. As this tape recorder is a three head machine; erase, record and playback, you can take advantage of this fact and utilise it to produce echo effects. By feeding the output of one track back into the input of another, the number of echo repeats can be varied by the input level control of the channel you are feeding into. For a more thorough explanation of tape echo effects refer to the article in the HSR February issue.

New For Old

To sum up, it's worth looking at the differences between the old 4000DS and the new GX-4000D.

Mechanically, the machines are of the same design with the only changes being the restyled buttons and control layout. The removable head cover is a real boon to all those who really do take care of their machines and clean the heads regularly. Another nice touch is the concentric level controls on both mic and line inputs, it's now far easier to fade both the left and right channels of a stereo recording by equal amounts at the same time.

The tape path remains as before, clear of any obstructions and makes for straightforward lacing of the tape and ideal for playing tape loops. The old style rubber 'press-on' tape reel holders have been replaced with the more conventional type of tape hub clip, which is a very welcome addition and holds the tape reels in place very well. Finally, the stereo headphone output now has its own level control.

These changes have definitely made the GX-4000D a better machine than its predecessor and I only wish Akai could have gone a little further and improved one or two other features. Perhaps this is just a 'stop gap' machine to respond to the current market demand for a basic tape recorder at a budget price and maybe a new, more up to date design is on the drawing board?


The new GX-4000D should, like the old 4000DS, become a popular machine not purely because of its price, but for the quality and flexibility of the features on offer, and should find a place in many home recording set-ups. The frequency response and signal-to-noise ratio are both very acceptable and for those who wish to embark upon the road of open spool tape recording, this machine is an excellent starting point.

Although the GX-4000D is primarily an old design, it does work well and bar the little criticism of its method of tape speed selection, represents very good value for money. Popular applications for this machine would include general recording, audio-visual work and one-man multitracking.

The GX-4000D retails for £250 inc VAT.

Further information on both machines is available from all Akai dealers or direct from Akai, (Contact Details).

Previous Article in this issue

Soundcraft Competition Results

Next article in this issue

Symetrix 511 Stereo Noise Reduction

Publisher: Home & Studio Recording - Music Maker Publications (UK), Future Publishing.

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Home & Studio Recording - Oct 1984

Donated & scanned by: Mike Gorman

Review by Paul Gilby

Previous article in this issue:

> Soundcraft Competition Resul...

Next article in this issue:

> Symetrix 511 Stereo Noise Re...

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