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Akai 4000DS

Stereo Reel to Reel Tape Recorder (1973-77)

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Akai 4000DS


The Akai 4000DS is a four-track, two-channel stereo reel to reel tape recorder for use with 7" reels.

The employment of a highly efficient induction motor and boldly designed flywheel in the 4000DS results in stable tape travel and reduced wow and flutter.

This feature coupled with a three head system including Akai's one-micron gap playback head assures clear playback sound.


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

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

Motor: 1 x SSM-1 4-pole induction

Reel size: up to 7 inch reel

Tape speeds: 3 34  7 12 ips

Wow and flutter: 0.15% (7 12 ips)

Frequency response: 30Hz to 23kHz (7 12 ips)

Signal to Noise Ratio: 50dB

Total harmonic distortion: 1.5%

Crosstalk: 50dB

Input: 70mV (line), 7mV (DIN), 0.8mV (mic)

Output: 1.228V (line), 0.4V (DIN)

Semiconductors: 11 x transistors, 4 x IC, 4 x diodes

Dimensions: 406 x 314 x 194mm

Weight: 11.4kg


mkII instruction/owners manual  English Deutsch Francais

service manual  English

mkII service manual  English

mkII brochure  English - k7sparky

mkII specifications  English Francais - SkyLounger

instruction/owners manual  English - Biro

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re: 4000DS

Got also a 4000DS. Outside in very fine condition, but unused for a long time. First issue, no fast forwind. Got it open and found all grease sticky. Cleaned and regreased everything. Some contact-cleaner applied to all switches, and after about one hour of work it works fine. Maybe the longest produced R2R from Akai, as the roots of this machine were in the 60's as 3000, then 4000, 4000D, 4000DS, 4000DSmkII ans so on till late 70's.
Does anyone know the difference between the DS and the DSmkII, apart from the "nipples"?

re: 4000DS capstan removal

Hi folks, I just picked up one of these, apparently in good condition. I am now "reeling" again after a few years! I think I understand the idea of removing the capstan outer cylinder to change to 3.75 IPS. I think it must not have been removed for a long time. The whole capstan spins when you turn the knurled top cap, and I'm not going to put vise-grips on the lower portion to hold it in place while removing the cap!

How can I nudge this thing off? I think I only have one 3.75 tape, but it's one of the important ones.


UPDATE: I got it off. I applied a bit of WD40, oriented the deck so I could get a better grip on the capstan with my fingers, and was just barely able to get the cap started unscrewing with my other hand. Once the cap was off, the cylinder slipped off nicely.

re: 4000DS capstan removal

Hey all, I recently found one of these in my dad's old stuff. The Akai 4000 ds! I have zero use for this. Just wondering if anyone might be interested in buying one or if you could direct me to a place to possibly get rid of??

re: 4000DS capstan removal

I have been after a 4000DS as I have an Akai XV which I have had for many years and is now starting to fail. My dad had a 4000DS back in the 60's and since he passed on I'm not too sure what happened to it. I would therefore be interested in buying yours as long as it is in good working order etc. Let me know what you would want for it

re: 4000DS

Got my 4000ds from a friend for free! This site was really what I needed got the owners manual and service manual downloaded now to get this unit up and running. Will post pics once it's cleaned and ready to go.

re: 4000DS

I have to say that this thread was so helpful to me i had absolutly no idea that there was a sleeve on this unit,this akai unit is so cool it has gotten me into the hobby of 4 track players ,absolutly amazing,i bought my 4000ds mk-2 at goodwill for 14.99 to resell it,but that is not gona happen ,this thing is so mint its like new and im keeping it,too listen to music this way is even better then lp,im in shock at how it changes the way you listen to music,these units were before my time barely ,because im 43 so i was a cassette guy, never even knew these things existed,but il never go back and by the way i only tried ipod once screw that.

re: 4000DS Only Plays Back Through One Side - Channel

Have an Akai 4000DS and will only play back through one side - any help?

4000DS not recording


My machine was working just fine, but now the record function isn't working after I opened it up to do some take up reel platter work. I do believe the electronics are fine and that this is some sort of mechanical issue. I'm not sure what I could have done. The light also used to turn on but now it does nothing when in record mode. I have signal hitting the preamps and it's visible and audible if I monitor source. I can also hear what's on the tape, but the record function is defying my logic at the moment. What should I do?

Fingers crossed that I can redeem this gem.

ellsworth audio company's picture

re: 4000DS not recording

Check to see if your record levers are making full contact with the record/pb switches.

re: 4000DS

How do you remove the small track switch to remove the cover to adjust the track heads. There seems to be a bit of over lap on the tracks. The tapes were recorded on another machine a Philips many years ago. I am hoping by adjusting the heads it will cure the problem? gus

re: 4000DS

You need a small hex-key, entering from beneath

re: 4000DS

Thank you Willemfrans found a small allan key off no bother. Will have to see if adjusting heads will get rid of double track sound?

re: 4000DS

Hi Guys, I have today purchased an Akai 4000DS. It plays back with no problem whatsoever. However, I am unable to record. When the 'Monitor' switch is in the 'Source' position there is sound, the VU meters happily flicker away and the volume can be controlled by the tape deck. When in 'Tape' position there's no sound at all, whether in Playback or record mode !! Can anyone assist? The red 'Record' light comes on but nothing has been recorded. In 'Record' mode the deck erases the tape. All help will be appreciated ! I thank you in anticipation. Kindest Regards.


I have had my 4000DS since 1984 and it is a great machine but the light (a type of glass diode) that fits between the two VU Meters has blown. Does anyone know the replacement part I need, assuming its still available that is. I have some great old recordings on AKAI, AMPEX and other tapes and some BBC Studio Masters including one for John Williams / SKYE album and it is the original masters and be a shame if I can't play them again. I did check schematic but not 100% sure of the part.

Be grateful for any help.
Many Thanks, Steve: Plymouth, England

re: AKAI 4000DS

The voltage is 6 volt.

Find a small bulb with free wires.
Just cut out the old bulb and solder the wires into
the little metal holes of the pertinax .

Allister Hadden's picture

Light Bulb

Was looking through rapidonline. com for parts . they have bulbs that have the wires on them do not remember what voltage they are . and cannot remember what the voltage is on the akai . They are not diode's they are just light bulb without fitting and are used on many bit off equipment for lighting up the meters . If they are the wrong voltage all you do is bais them up to suite . My Technics tape deck uses them on the meters and they are 18 volt . . They are called Wire ended Filaments Bulbs . 5.0 volt 41-0220 (part nos) 12 volt 41-1225 (part no ) that thiers nos .

There are other sizes and voltages hope this helps . Well checking the wiring diagram to see how the head switch is wired . Mine just spat out a contact . Needs new one or make one from another switch off the same make ,and era .
Well it is wired on the 5 volt winding off the transformer so the 6 volt bulbs will do the job and think they are just held with a blob off UHU glue .
So the Rapid Electronics part 41-0220 will do at 26 pence each plus vat min delivery is £4.99.
The do a good range off leads and connector as well .

Hope this was helpful


Hello everybody, I am the

Hello everybody, I am the owner of a Akai 4000ds for a few month's now , And I really love the thing!
But I have a problem, The RWD / F.FWD button is stuck, i cant move it , and i am affraid to pull too hard cause i might break it.. anyone has the solution?

Thanks a lot


The F-forward/F-backward knob is blokked by a steel
ball in between its base plate and that of the play-back/record knob.
This prevents using both at the same time

Sticking RIGHT Recording Level Control - Button not moving

I have exactly the same problem. Recently purchased the AKAI DS4000 from eBay. Everything working apart from the RIGHT Channel center recording level control which is supposed to pull outward to monitor a mono recording.
This is not moving at all. I do not want to risk applying too much force for fear of damaging the control or the unit.
Hence I am hearing two mono-tracks at the same time in the Headphones or from the line-outs at the back of the deck.
Makes it difficult to transfer the single track to computer.
My solution for the moment is to just use the appropriate line out (left or right) exclusively from the back of the deck to isolate the track. Monitoring through the headphones is not possible however.

Did you ever get a solution to the problem with your deck?


Stereo recording

Hi all can anyone help just purchased a 4000ds mkii all work fantastic, apart from trying to record in stereo via phono input, left channel perfect vu meter, right channel no control of input either off no sound at all or full on right channel on stereo noise. Any pointers, much appreciated

Stereo recording

Hi all can anyone help just purchased a 4000ds mkii all work fantastic, apart from trying to record in stereo via phono input, left channel perfect vu meter, right channel no control of input either off no sound at all or full on right channel on stereo noise. Any pointers, much appreciated

tape plays too fast

I purchased an AKai 4000 DS MK II and was told it worked. However, when I load a 7" reel (Epic Stereo Tape Four Track) it plays too fast. Any suggestions on how to fix this so the sound plays at the correct speed? I appreciate your help.

re: tape plays too fast

Two possibilities.
1) If you live in the US of A, the 50/60 HZ. screw between the reels should be level with the front plate.
If it is peeping out about 10mm, your device is running 20 % too fast.

The 50/60 HZ. switch at the back won't do any thing to the speed.

2) There is a sleeve around the capstan for high speed recording/playback, remove it.

Akai 4000DS playing too fast?

The Akai 4000DS uses a single AC motor to run the whole beast, a 4-pole induction motor if my memory serves.
The motor can and only does run at one speed: however, the machine can be set up to run at 2 speeds; either 3-3/4 ips (inches per second) or 7-1/2 ips.
You don't mention what the indicated playback speed for that Epic Stereo Tape that you're trying to play is supposed to be. Given that you have this problem, I'll assume that you are not very familiar with the capabilities of your machine, and perhaps about open-reel tape decks in general?
If your machine appears to be playing at some steady speed, and it sounds approximately twice as fast as it should be, then there is a very simple fix to your problem.
The Akai 4000 has a rather unique method of selecting speed! It isn't exactly intuitive, so I suppose that this is what is messing you up.
There is a switch on the front panel for EQ during playback for either of the two speeds, so that is basically just a tone control and doesn't affect what the motor does. Ignore it for the moment.
Since the motor only runs at one steady speed that is governed by the AC mains frequency (50 Hertz in Europe and most of Asia, 60 Hertz in North America & Japan), Akai uses a mechanical method to change the speed.
What they do is: They change the diameter of the capstan!
The capstan is the steel pin that presses against the big rubber wheel, which is called a pinch roller. It is called that, because if you notice, the tape is "pinched" between that steel pin and the rubber surface of the wheel/roller during playback & recording. This arrangement maintains the steady speed required for proper operation.
What Akai does to change the operating speed is that they use a metal sleeve that fits over the capstan pin, and it is held in place with an attractive little metal stub shaped like an eraser from a mechanical pencil. This little stub screws onto the end of the capstan pin, and it holds the larger diameter capstan sleeve that is used when you are operating at the higher speed of 7-1/2 ips.
I'll assume that your Epic Tape is intended for playback at 3-3/4 ips, which is the lower speed for which you need to remove the capstan sleeve and locking stub.
If this is the case, then what you need to do is to shut off the machine to stop the motor entirely, since when the machine is on the motor is always running, and the capstan is always spinning, even when you are fast-forwarding, rewinding, or just plain idling!
Once the motor stops spinning after turn off, you can unscrew the little capstan stub. This should be easy enough, given that its surface has knurling on it to facilitate grip.
Once it's been removed, the outer capstan sleeve can be slid off. You have just switched your machine from 7-1/2 ips to 3-3/4 ips...congratulations!
Now, you don't want to lose those little bits!!! There is a pin located above the black head nest cover just for this purpose: it is an exact replica of the capstan, you just put the outer sleeve and metal stub/screw on it, nice and safe!
I hope this solves your problem, I've got two of these machines and have owned one of them for 35 years. I've seen many others, and have NEVER come across one where the motor runs at a faster speed due to any defect. I think this all but impossible, given that it is a simple type that locks onto the mains frequency; no speed control circuitry is used in the machine whatsoever (servos, for example).

Akai 4000

Some of those decks had different size capstan sleeves for different speeds and maybe for different line frequencies.
You might check the voltage selection switch on the back to make sure it is correct.
Also the capstan belt might be riding on a lip around the motor pulley.
Is the speed constant? Is there wow and flutter?
Is your tape verifiable? Are you certain of it's quality and playback speed?

dropped my 4000ds mkII - stereo output broken

so ...

I dropped my akai 4000ds mkII today while moving it :-( when testing it after the accident I found everything still works ok except for stereo playback. only my right channel seems to work - left doesn't output any signal. anybody got any idea about what exactly it is i'd have to fix here? already opened it up but can't really see any loose parts ... would be great to have it working again. except for this problem the unit is in great condition (even after it fell ;-)

edit ... everything working fine again ;-)

Tape speed akai 4000

Hi there.
Anyone heard of a 4000 running at 3.25, instead of 3.75?
There's a chap near me selling a 4000ds saying some early models came out running at 3.25, hence his machine, which he is selling, will play my tapes at the wrong speed.
Although, because I plan to copy them to a computer, I can speed them up to the correct speed with software.
Is there a variable resister to alter the speed? Could that be it?
Any thoughts...

New zealand

re: Tape speed akai 4000

I have some tapes recorded in 1968 at 1.875. The slowest speed of the Akai 4000DS I have is 3.75. I plugged the Akai output into an amp, then used an inexpensive Griffin iMic, to record them to my Mac. I downloaded the free Audacity software and used its wonderful Change Speed menu item which affects both tempo and pitch. Works like a charm for spoken word audio. I set it at "-45"


Akai 4000

Most of the reel to reel decks had synchronous motors in them that locked to the AC line frequency.

reel to reel nut's picture

Tape Speed Akai 4000

Hi Steve
there is a switch between the reels for 50/60 Hz this will need to be set according to the voltage for your country (consult the owners handbook) as it alters the position of the capstan belt on the flywheel and must be adjusted with the motor running . this is almost certainly the problem as people often fiddle with things they dont understand !! it turns in or out 180 degrees with a flat screwdriver. if this doesnt cure the problem then the motor run capacitor may be faulty although this is unlikely as these are very robust machines . Good luck . Gordon UK.

Thanks Gordon. I'll buy it

Thanks Gordon. I'll buy it and let you know how I get on.
Many thanks.

Newbie question

I just dug my father's old reel to reel player out and would love to give the old tapes a spin. Problem is the dang thing will not Play. FFwd and Rewind work great but when I switch it to Fwd nothing happens.

Now for the newbie question(s)...

I assume the pick-up reel should be pulling the tape with the capstan regulating speed. Is this the case and I have an issue in the guts somewhere?

The capstan is spinning. In fact, it always spins. That said, there is no pinch on the capstan post. Is this the issue? Seems that if the pinch was there and was pulling the tape but the pickup reel was not spinning, the tape would just pile up.

Any help would be appraciated



Clean Heads?

I recently did exactly the same thing.
The machine seems to work well but tapes are a little worse for wear...

Does yours move tape when in FWD but just no sound?

If this is the case, same thing happened for me. Fixed it by cleaning heads for a long time with surgical spirit then playing a tape for ages. To begin with there was no sound then started muffled and got clearer and clearer.

When you switch to FWD the rubber wheel (?) pinches the tape against the spinning capstan. This is a mechanical movement so maybe something has worked loose.
Have you got the auto off guide engaged? that might be doing something?

Best of luck

reel to reel nut's picture

Newbie question

Steve , the capstan and pinch roller together pull the tape through and the takeup reel just collects the tape by way of a slipper clutch in the takeup hub. If the pinch roller is missing then the machine wont play . Also is the pause on(press the little chrome button on the right hand side of the machine to release pause) the takeup reel should now spin.

Reel sizes

Can I use two different size reels, ex: 5" running to a 7"?

reel to reel nut's picture

reel sizes

Yes you can ,however it might spill tape slightly when stopping the tape from ffwd or rewind due to the gyroscopic effect of the larger reel. Playback will be fine though !!

Reel sizes

Thanks, and here's another question for ya, I'm not sure what is causing it but when i get to a certain point in the tape it starts squeal. Which is why i asked the first question, I tried putting on two of the same size reels and I didn't have a squeal.

Squeaky tape

Place tape in a Ronco food dehydrator for 12 hours, make sure that the dehydrator is not the fan type that has magnetic motors, just use the heater element type. This should magically fix your problem unless the tape recorder has too much tension. Be sure to clean the guides and heads (tape contact parts) carefully with Acetone to remove any wax shed that might be stuck to them. If you do not, the cured tape will likely stick.

The circular type plastic food dehydrators make a perfect tape oven as it is called.

reel to reel nut's picture

reel sizes

Hi , are you using Ampex tape by any chance (406,407 and 456)or Radio shack Concertape (on the black reels) most of these and some Scotch tapes from the mid 80s have a condition called sticky shed syndrome which is caused by the binder which holds the oxide to the base breaking down and absorbing moisture ,the tapes will squeal nearer the end than the start .Google sticky shed and have a read its quite interesting . Gordon.

Squealing Scotch Tapes - any fix

I just found this because I have the same issue. I thought it was the machine.

Is there anything you can do to fix this? I have some old radio programs that I'm trying to convert to MP3s. Did I just wait a decade too long?

- karlp

Reel sizes

It's scotch, and its at the beginning of the tape i haven't gone all the way through the tape to see if its stops at one point but its near the beginning of the tape, and okay I'll search it.


The reel to reel plays back it just sounds like the chipmunks. What am I doing wrong??

reel to reel nut's picture


either your tape is recorded at a slower speed than your playback speed or your machine is faulty (unlikely) What machine do you have and were your tapes recorded on this machine ?? Gordon.

akai 4000 ds mkII reel to reel

where can I get this machine serviced and obtain tapes for it? please

Steve, Mississauga, Ontario, Canada

Akai 4000DS service in Mississauga, Ontario (not New Mexico!)

Hi Steve,
If you are still searching for a good tech experienced in all things Hi-Fi and with Akai 4000 experience as well, I highly recommend Vlatko Lepki of L-Tronics.
He's at 3135 Universal Drive, just off Dundas West between the 427 & Dixie Rd.
Ring him on: (905) 602-7523

He's very quick, his prices are extremely fair, and he doesn't charge for "estimates".
HIGHLY recommended, I've used him dozens of times and can't say enough good things about him!

Reel to Reel Service

My personal recommendation for reel to reel service is: Joey Stumpf in New Mexico. Email - joeystumpf@hotmail.com. I have read nothing but positive reviews, and very highly recommend her. Web site is: http://www.fieldengineer.homestead.com. Really worth checking out, I promise. Be advised however that she specializes in RESTORING reel to reels, not just particular repair issues, so it can be quite expensive, but well worth it if you value your machine and recordings. You will get a fully restored operational machine back! She is working on my Teac X2000R now, and I can hardly wait to get it back in my system.

Tapes become a different issue. I have "Googled" recording tape and found some sites that offer them. Again quite expensive -- compared to what they cost 40 years ago. You could also try eBay for raw tape.

I hope this helps you out some, and good luck!


Tony B's picture

Akai 4000DS Mk2

I have an old Akai 4000DS MK 2 reel to reel recorder which I am currently using to transfer old tapes to CD. It has several faults, needs a really good clean and servicing but it does actually work (I haven't tried recording, just play-back). A couple of knobs are missing. After I have copied my tapes, it is, alas, bound for the tip unless anyone cares to collect it (free). I can't be bothered advertising it. I'm in County Durham (DH9...). If anyone is interested e-mail me at: t.baker101@btinternet.com

fbdobb43's picture

Akai 4000DS Mk-II Reel to Reel Tape Recorder

Newbie here.
In process of purchasing above recorder.
I recorded music off the radio in the 1960's ...while in college. Recently found the box with the tapes.
In order to play the tapes....do I need a amplifier and external speakers...or, can I just play the tapes on this machine?

Tony B's picture

Akai 4000DS Mk2

I'm in a similar position except that the tapes were in the loft and I still have the machine. After all these years... it worked. The machine has no built-in amplifier or speakers so either need to connect to (e.g.) a hi fi or use headphones (it does have a headphone socket). Sockects on back are left and right phono i n and out (for sockets in all) and a 5-pin din socket.

External Speakers

I am looking for a the same answer whether external speakers need to be used. It is hard finding speakers which take banana plugs like the 4000DS seems to need. If anybody knows the answers to this I would appreciate a comment. Thanks

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