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Reel To Reel All discussions pertaining to reel to reel decks. These include general usage, recording, playback, and service questions. For subjects related to tape itself, see the Open Reel subforum under this one. Obscure service subjects that don't quite fit go in the Help and Do It Yourself subforum.

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  #1  
Old 10-11-2017, 02:22 AM
AkaiR2R AkaiR2R is offline
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Reelspin Akai 4000DS - small problem (or not?)

Hello everyone!

Recently I became the owner of nice old Akai 4000DS. It's in good and nice shape generally, every function and button of it is working fine. But… it has one problem, like almost every old device. Playing at 3 ¾“ is good, without any deviation of sound and on constant speed. When I put that little „cap“ on capstan to play at 7 ½“ problem starts. In the first few seconds tape is running well, then it starts to get slower and slower until it completely stops spinning. When it stops running tape electric engine is still working without problem and any change of speed, also running capstan, but reels are like blocked. Like something is blocked or „drifting“ inside. I replaced a belt, put in new one, but problem remains. When I turn it back to 3 ¾“ everything is okay. Pinch wheel is also in nice condition, rubber is still soft, not hard and without damage.

What could that be, is it some big problem or something that just needs some greasing and adjusting? I'd really appreciate some good advice what to do because I really like this old Akai.

Thank you in advance for your help!

P.S. Sorry for possible mistakes, I'm not native English speaker.
  #2  
Old 10-11-2017, 04:12 AM
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Big Kelv Big Kelv is offline
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Welcome to TH!

The Akai has only one motor (engine) so the only difference is putting on the sleeve (cap).

Compare to the bicycle - when you pick the larger gear at the front, you have to pedal harder.

This is what the motor is having to do.. Maybe motor is weak, there could be a number of reasons why.

Question: When you put the sleeve onto the capstan, do you have the screw on lock fitted?

Regards, Kelv
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  #3  
Old 10-11-2017, 05:52 AM
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Quadzilla Quadzilla is offline
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I had that exact same problem with my GX-4000D. It would play great at 3 3/4 ips, but when I installed the capstan sleeve and played a tape at 7 1/2 ips it would slow to a stop after a few minutes. I had a new belt installed, and at the same time I had the supply reel dismantled, cleaned and lubricated. It works fine now. Good luck.
  #4  
Old 10-11-2017, 07:33 AM
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As Big Kelv suggested have you the screw down cap that holds the capstan sleeve in position .......If yes then you need to check the take up reel torque but a good clean and lube of both the supply and take up reels mechanisms will do only good and of course the motor and it's capacitor could be effecting things as well.
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Old 10-11-2017, 07:53 AM
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Big Kelv Big Kelv is offline
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As Quadzilla has suggested, the supply reel (on the left) may need a bit of lubrication.

If the tape is not spooling out onto the floor, the take up reel is OK. The capstan and rollers do the work not the take up reel.

The reason I ask about the sleeve and screw down cap (Red_Ox, I suspect agrees) is that the Akai 4000 series are often found without both of them. Also, some think the cap is just to hold the sleeve onto the stowage.

I hope my posts don't seem belittling to the OP but his/her native language is not English and this is a common problem.

Hopefully the already suggested solutions will sort things out. I owned a 4000DB for 25 or so years and thinking of getting another.

Remember - replacing a belt is not a miracle cure for anything.

Best regards, Kelvin
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  #6  
Old 10-11-2017, 10:52 AM
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rojoknox rojoknox is offline
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Greetings from RojoLand!

+1 on servicing the supply reel table on your Akai 4000DS. I have one as well (plus the successor 4000DS Mk-II which also has a little of that end-of-reel sluggishness, and has since it was new!). The supply reel table contains a spring-loaded, felt-lined slip clutch that ironically needs to be lubricated to operate properly. There are a fair number of washers, shims and such so beware when disassembling. The service manual has an exploded view to help with the procedure.

My 4000DS' supply reel table had been tampered with before I was given the machine (and I got a small baggie full of stray parts "left over"—hoo-boy). The machine had very little back-tension — just the opposite of your problem. Turned out the "tamperer" had mis-assembled the reel table. With help from the manual, I put it back to rights, and — wonder of wonders — I had back-tension! Deck plays nicely, and does not slow down near end-of-reel at either speed.

To echo others here: Definitely screw the retaining thumb-nut onto the capstan when using the 7-1/2 IPS capstan sleeve. Without it, the sleeve can and will just slide right off, likely damaging tape (unless you're running the deck horizontally).

Take care,
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  #7  
Old 10-11-2017, 11:56 AM
AkaiR2R AkaiR2R is offline
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Quote:
Originally Posted by Big Kelv View Post
Also, some think the cap is just to hold the sleeve onto the stowage.
Also, I'm almost one of them.

Sometimes solution is just around the corner, you just need to ask right people.

Until now I was playing just with cap on capstan, without sleeve. Today I put both sleeve and cap and voila!, my problem is gone. I literally didn't know that I need to put both of them to play at 7 1/2" - my shame.

I'm so happy that this little thing solved my problem. Now we have one more to solve!

While recording I have a big difference between source and the tape. Source is perfect clear and I can set nice parameters on VU meters. When I turn recording on source stays as good as earlier, but turning on to tape gives me different results on VU meters and in sound quality and I need to volume up both left and right channels, left one even more than right one. So, there is huge difference between source and tape.

It results in pretty bad sound quality of recorded track and while playing other tracks sound is "blurred", unclear and a little bit silent. I know that this little device must give some better results.

Heads are cleaned with alcohol and they are looking nice and shiny. I also tried to demagnetize heads, but without any improvement of this problem.

Your opinion?

Last edited by AkaiR2R; 10-11-2017 at 11:59 AM.
  #8  
Old 10-11-2017, 12:19 PM
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Big Kelv Big Kelv is offline
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Reel to reel is a steep learning curve if you've had no experience before (my 4000DB was fairly new when I obtained it in the 1980's). Despite what many here will say, there is little to go wrong on with the 4000 series. Mechanical cam failure being the worst (the mechanical links behind the main transport controls).

Before getting too excited, are you using a decent quality tape? Don't start ripping the deck apart until we know it's actually the deck.

Regards, Kelv
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  #9  
Old 10-11-2017, 12:30 PM
AkaiR2R AkaiR2R is offline
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Quote:
Originally Posted by Big Kelv View Post
Reel to reel is a steep learning curve if you've had no experience before (my 4000DB was fairly new when I obtained it in the 1980's). Despite what many here will say, there is little to go wrong on with the 4000 series. Mechanical cam failure being the worst (the mechanical links behind the main transport controls).

Before getting too excited, are you using a decent quality tape? Don't start ripping the deck apart until we know it's actually the deck.

Regards, Kelv
I have a little bit experience with one Unitra M2405S reel to reel, and I think it's fair to say that this Akai is another galaxy for Unitra.

I have a new one Basf DP26 tape (it may not be the premium, but it's being recorded for the first time). So I suppose that sound should be much better. I'm thinking about heads azimuth?
  #10  
Old 10-11-2017, 02:49 PM
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Before you take your machine apart you should try a pre-recorded tape on your machine. Or one that was recorded on another machine to see if it plays fine on yours.
This will tell you if it is your record heads or playback heads.

I also can’t stress enough that the heads are perfectly clean..

Let us know what you find.
And do not worry about your English... you are doing just fine.!

Graham
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Last edited by nascar03; 10-11-2017 at 02:53 PM.
  #11  
Old 10-11-2017, 03:35 PM
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Greetings from RojoLand!

Another factor with clarity of playback will be how you have the Tape Selector and Equalizer switches set. The former is labeled "S. R. T." (for Akai's "super range tape") and "Normal." For your BASF tape, set it to Normal. And, of course, the Equalizer should be set for the tape speed in use. (Use 7-1/2 IPS for anything you care about; 3-3/4 IPS to save tape if you don't mind the lesser quality.)

The deck should do better with tape such as Maxell UD, or new-manufacture tapes like SM468 and Capture 914/930. For those, use the "S. R. T." position.

Also, if you can, could you please post clear photos of the heads? The amount of wear and residual dirt present will have a bearing on sound quality, and we can't judge that without seeing the heads.

Take care,
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J. E. Knox "The Victor Freak"
  #12  
Old 10-11-2017, 03:37 PM
AkaiR2R AkaiR2R is offline
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Quote:
Originally Posted by nascar03 View Post
Before you take your machine apart you should try a pre-recorded tape on your machine. Or one that was recorded on another machine to see if it plays fine on yours.
This will tell you if it is your record heads or playback heads.

I also can’t stress enough that the heads are perfectly clean..

Let us know what you find.
And do not worry about your English... you are doing just fine.!

Graham
I tried one that was recorded on another machine and sound is as described. It's not horrible, but it's not as it should be. There is no any distortion, just muffled sound, but not so much that music is impossible to listen. I just think that it should be better. So, playback quality is always the same: on tape recorded on other machine and on one recorded on Akai. Maybe the one recorded on Akai is better, but I suppose it's normal. However, while recording there is huge difference between monitoring tape and source.

Btw, thank you all for your help!
  #13  
Old 10-11-2017, 03:42 PM
AkaiR2R AkaiR2R is offline
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Quote:
Originally Posted by rojoknox View Post
Another factor with clarity of playback will be how you have the Tape Selector and Equalizer switches set. The former is labeled "S. R. T." (for Akai's "super range tape") and "Normal." For your BASF tape, set it to Normal. And, of course, the Equalizer should be set for the tape speed in use. (Use 7-1/2 IPS for anything you care about; 3-3/4 IPS to save tape if you don't mind the lesser quality.)
While recording and playback Tape Selector switch was set to "Normal" and Equalizer on 7 1/2", everything as described. What is the purpose of switch on back side of machine, above RCA entrances? There is mark on it "High" and "Low".

I'll try to take photos of heads and post them tomorrow!
  #14  
Old 10-12-2017, 09:06 AM
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rojoknox rojoknox is offline
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Greetings from RojoLand!

Oddly enough, although my 4000DS also has that "High-Low" switch on the back panel, it's not mentioned or even pictured in the 4000DS operator's manual! It's a line-input sensitivity switch if I recall correctly. If you are feeding in a line-level signal and getting 0 dB readings on the meters with the Line In controls in the range of 10:00 to 12:00, the switch is in a correct position. Not sure, but it might actually be associated with the DIN input and thus irrelevant to the RCA inputs. The DIN input works only with the *mic* input controls. As far as I'm concerned, the DIN input is a solution looking for a problem.

Take care,
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J. E. Knox "The Victor Freak"
  #15  
Old 10-12-2017, 10:01 AM
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Big Kelv Big Kelv is offline
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My DB also had the high/low switch. I've just looked at the schematics for the MKII DS and it doesn't seem to appear on the diagram. If it is related to the line/din, it should be set to the high position due to the higher level of line over din.

Regards, Kelv
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Old 10-12-2017, 12:50 PM
AkaiR2R AkaiR2R is offline
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Looks like this "High - Low" switch is mystery to all of us. It's true that this switch isn't mentioned in user manual of machine.

As I promised, here are photos of heads. I tried to take them as good as I can, they are not perfect, but I hope that photos are clear enough to see condition of heads. I'm really interested about your opinion.
Attached Images
File Type: jpg IMG_9986.jpg (42.5 KB, 28 views)
File Type: jpg IMG_9988.jpg (67.9 KB, 29 views)
File Type: jpg IMG_9989.jpg (60.8 KB, 30 views)
File Type: jpg IMG_9985.jpg (45.1 KB, 28 views)
  #17  
Old 10-12-2017, 02:01 PM
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Greetings from RojoLand!

Thanks for the head pix. They do show a fair amount of wear but don't appear dead yet to me. (Indeed, my 1979 4000DS Mk-II shows a little more wear than that so you're better off.) I think you might try recording with Maxell UD or a brand-new reel of SM468 or Capture (splicit.com) or similar new-manufacture tape. The record-playback quality *should* improve. If not, the deck is in need of service — calibration, perhaps recapping as well.

Checked my 4000DS' current high-low switch position — it's at High.

Take care,
—
J. E. Knox "The Victor Freak"
  #18  
Old 10-13-2017, 11:01 AM
AkaiR2R AkaiR2R is offline
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Quote:
Originally Posted by rojoknox View Post
Greetings from RojoLand!

Thanks for the head pix. They do show a fair amount of wear but don't appear dead yet to me. (Indeed, my 1979 4000DS Mk-II shows a little more wear than that so you're better off.) I think you might try recording with Maxell UD or a brand-new reel of SM468 or Capture (splicit.com) or similar new-manufacture tape. The record-playback quality *should* improve. If not, the deck is in need of service — calibration, perhaps recapping as well.

Checked my 4000DS' current high-low switch position — it's at High.

Take care,
—
J. E. Knox "The Victor Freak"
Is it possible to do some calibration of the deck while just listening to playback and how it sounds? Because I don't have any of special devices for calibration. Can I improve something doing head adjustments according to user manual for the deck (there is chapter V. Head Adjustments)? There is description of head height adjustments, head slant and head azimuth adjustments. How hard is any of these to do and can I expect some improvement after those?
  #19  
Old 10-13-2017, 01:28 PM
AkaiR2R AkaiR2R is offline
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Little update: while recording on 3-2 sound quality is fine, could be better but it's okey. Left channel working, needle moving fine, right one is still. On stereo there is a problem: during recording left channel signal is very low and right one is better. Left one is here in "flashes", it's not constant. Same during playback, left one is showing signs of life, but just on moments, so I can't get full and nice stereo. Recording and playback on 1-4 is almost same problematic as stereo. :(

What can/should I do? Will some electric contact spray on track selector switch help, also on another electric contacts and switches?

During monitoring source everything is fine in any position of track selector switch. Listening to stereo on already recorded tracks is also fine, same as 3-2 and 1-4.

Last edited by AkaiR2R; 10-13-2017 at 01:38 PM.
  #20  
Old 10-13-2017, 02:00 PM
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Greetings from RojoLand!

I would not recommend messing with head adjustments if you don't have the proper gear and experience. You're more likely to make things worse than to improve them. The alignment tape alone costs around $135, and you'd also need an oscilloscope (preferably dual-trace) and an AC millivoltmeter (preferably an analog type with an actual meter, such as the Leader LMV-181 or equivalent). Diddling the heads is not a trivial matter and should be a last resort, best left to pros. Heads that have been used for some time and have visible wear should NOT be messed with.

Re the 1-4, Stereo, 3-2 knob: Normally that should be in Stereo position. The other two are for mono-only use. Note too that the right-channel mic level knob pulls out; it's labeled "Pull for Mono. Use." It simply turns off the right-channel amplifier. The head switch in 1-4 position should have the same playback sound as in Stereo, but in 3-2 the channels should swap. In record, 1-4 activates only the L channel record and erase heads, and 3-2 only the R channel record and erase heads. It does sound like much of your problem could be dirty switches, including that head switch. Get yourself a can of DeoxIT D5. It's rather spendy (right now at Parts Express, $13) but definitely does the job. Use *sparingly*; don't let fly all over the place. And if you don't already have the service manual, you can download it at HiFi Engine. It details how to open up the machine (remove from case, remove front panels, etc.). You'll need a metric hex key to remove the head-switch knob; all else should be a #1 or #2 Phillips screwdriver. (My 4000DS is missing its head-switch knob and a couple other parts; search is ongoing!)

The 'S.O.S.' (sound-on-sound) switch caused me grief on my 4000DS. Had to actually remove it, disassemble it, polish the contacts, reassemble and reinstall it to get it working properly. S.O.S. has little value and I strongly recommend leaving it OFF. That kind of function is better done on higher-end machines (think Teac A-3440, a four-channel deck).

I looked up the BASF DP 26 tape you mentioned. It is (nominally) 1/2-mil; that's not particularly recommended because of its thinness but isn't bad for what it is. (There is a BASF TP 18 3600-foot reel that's even thinner.) Again, get yourself a reel of something like Capture 914 or 930, or SM468. Or some Maxell UD from the Dock-o'-the-'Bay (get ready for sticker shock). That plus a good cleaning may well be all this machine really needs. Keeping fingers crossed!

Take care,
—
J. E. Knox "The Victor Freak"
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