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Akai ap-d33 issue

quadmatrix82

quadmatrix82

AK Subscriber
Subscriber
Hi All, picked up a lovely Akai AP-D33 direct drive turntable today, unfortunately the 33 speed is VERY LOW - I tried to adjust the pitch but it doesn't help - if I switch it to 45 speed I can adjust the pitch to get 33's to play ok on the 45 speed only. Can anyone help me to fix this properly?? Much appreciated thankyou!!
 
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Yes, you need to open it up and spray DeOxit on the innards of the pitch controls and the contacts of the 33/45 selector switch(es). And then work the controls all around. That usually solves the problem.
 
The problem is very common on the AP-D33 and other Akai DD turntables from that era, along with the plastic bit on the back of the tonearm coming unstuck and slowly sagging. There are a couple of trimpots (variable resistors) that can be adjusted underneath to vary speed - apparently anti-clockwise increases the speed. Just make sure the power is off, adjust them up, turn the power back on, and check for speed on the stroboscope, while turning the main speed control at the front around. It can also help to spray the trimpots with Deoxit, and move them about, while you're at it, as well as spraying the main speed control and 33/45 switch internals a few more times while operating them, to make sure all rubbish is removed from them. Some people here on AK have discovered it sometimes takes several goes with Deoxit to remove all the crud and regain speed. Here's some photos someone put on the net (credit to the original poster), pointing out where the trimpots are, for an AP-D30, which should be very similar, if not identical, to your AP-D33.

-Don
 

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Hi Don, thanks heaps! I tried adjusting the resistors both clockwise and anticlockwise - the speed on the 45's is perfect but the 33 speed is still very slow, i noticed some other variable resistors in the ap-d33 as well, should I try adjusting those instead?? Not sure what they do?? I tried to Deox the switches, pitch knob and the variable resistors but no success yet..is it possible that the resistor is faulty for the 33 speed??
 
quadmatrix82 said:
Hi Don, thanks heaps! I tried adjusting the resistors both clockwise and anticlockwise - the speed on the 45's is perfect but the 33 speed is still very slow, i noticed some other variable resistors in the ap-d33 as well, should I try adjusting those instead?? Not sure what they do?? I tried to Deox the switches, pitch knob and the variable resistors but no success yet..is it possible that the resistor is faulty for the 33 speed??
Click to expand...

No, the main thing that goes faulty with trimpots and potentiometers are that they get dirt between the moving contact and the resistance track. That's why a good cleaning will sometimes fix the problem. They are usually fairly reliable as far as faults go - they really usually only get dirty, or burn out when other electronics fail and put large electric currents through them. But if that was the case, they would smell bad, and would probably look very charred in the near vicinity - eg the circuit board! They'd maybe smoke a bit, too when you turned it on! :D However, I may be wrong (wouldn't be the first time:scratch2:) - the ones that Akai fitted to turntables from that era may be a bad batch. They don't cost very much, so you could try replacing them. Just check the code on them first for details of the resistance for the trimpots, or measure them with a multimeter out of circuit - the resistance will be between the two outside pins - the centre pin is the moving contact, not the resistance. The other trimpots may be for things such as phase, and probably won't make any difference to speed. You could try them, but note where they are set first, and if there is no difference to speed, return them to the same setting.

It may be a problem with some of the electronics in the speed control section - I'd replace the electrolytic capacitors first, as they often are the most problematic of electronic components. But as I don't have a service manual for one, I'm just guessing. You may have to get a service manual, but as there aren't any free ones on the net for Akai DD models, you'll probably have to buy one.

-Don
 
There is definitely a problem that develops with these Akai models that is beyond just oxidization in the pots. In its earlier stages you can compensate internally but I have come across several by now that still can't be bought up to speed. I repair turntables all the time so have definitely eliminated the basic issues which usually cause issues.

There must be a component failure elsewhere - most likely one or several capacitors but as I have not yet solved the issue I can't advise further. But I just thought I'd post here in case others find this thread looking for answers. If anyone can offer further insight into this particular model, please do so :)

I don't have a service manual, and at this stage the relatively low value of the model means I've chosen not to invest more time in finding a solution yet... once I get about ten of them sitting here waiting I may press further :)
 
I've got one with the same problem, tried to clean the pot's with no result, I'll change the electrolytics when I don't have anything else to do.
 
A little guide to solve the problem:
  1. Open up the turntable and spray a deoxidiser inside the pitch control and 33/45 selector switch; operate repeatedly these controls to facilitate the action of deoxidiser and then wait a few minutes for complete evaporation of the product.
    Sometimes this solves the problem.
  2. If previous operation didn't allow resolution of the problem, then go to check all electrolytic capacitors and replace those that are not in optimal conditions; this obviously requires use of a capacitance/ESR meter.
    If you don't have these tools, then replace all electrolytic capacitors (these electronic components are cheap and easily available).
  3. In my case problem was the presence of a high loss capacitor (C6 - 0,47 μF/25 Volt).
    This faulty capacitor was responsible of a partial short-circuit to ground of the transistor TR3 piloting signal with the consequent failure of the speed control circuit.
    Replacing this capacitor the problem was completely solved.
    To conclude maintenance, I replaced the resistor R15 (= 10 kOhm) with a 12 KOhm resistor and the resistor R16 (= 8,2 kOhm) with a 10 KOhm resistor. The reason for this replacement is that, with the original resistors, the right speed was achieved only by turning trimmers VR1 (33) and VR2 (45) fully counterclockwise (max resistance).
    With this simple change also this problem was completely solved.
P. S.
After repairing is advisable to perform a complete recalibration of the electronic circuit, following the instructions written in the service manual (easily available on the net).
This operation require only a digital multimeter of good quality (currently it's possible purchase one of these instruments with a few Euros/Dollars).
 
squirting the pitch adjust pots with servisol 10 switch cleaner and working them back and forth about 50 times cured a similar problem i had on an akai ap-206c... took a few sessions though to get them clean..and both speeds stable.. beyond that..i guess a service manual is needed :dunno:
 
giancarlopel said:
A little guide to solve the problem...
Click to expand...

I don't know if you will read this, but I've successfully fixed my AP-D33 by following your guide.
I didn't change the resistors, just changing C6 did the trick.
Now I can listen to 45rpm records too (earlier I managed to slow down the 45 rpm speed to 33rpm, the 33rpm mode was waaaay too slow).
Thanks a million! :banana:
 
Thanks for letting us know about your fix, ogisha007, and for the original fix, giancarlopel - I must have missed seeing that. I'd replace all the other electrolytic capacitors while I had it open - if one has failed, chances are the others aren't far off it. Still, after 30 years they've had a good life - I've had ones fail recently in modern electronics just out of warranty:no:.

Edit: oops, I see giancarlopel also suggested replacing them all. I should read things more carefully. Oh well, you can never have good advice too many times.:D
 
AP-D33 speed issue.

Hi folks,

I am having the same speed issue with an AP-D33; in my particular case, the stroboscope stops moving accordingly with the 60Hz setting, which is plain wrong, as I am located in Australia where we have 50Hz. Also, even when the 60Hz dots stops moving, the playback is way too slow. This happens for the 33RPM setting, I haven't tested it yet for the 45s.
I have read the other posts and I will shortly proceed with cleaning and if necessary replace some capacitors. In the meantime, I thought it would have been a good idea to take and share some hi-res pictures or the interior of the turntable, as I have seen that those two available are not very clear; I have taken pictures of everything, so that they can be used for reference for other issues, should they arise.

I will post my advancements.

Cheers,

Stefano.
 

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AP-D33 more pictures ...

More pictures ...
 

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Solution found ... or so I hope!

Ok,

I found the solution to this and other potential problems; I am attaching the page from the service manual (full URL posted above ... which describes precisely what to do and what each trimpot/potentiometer is for.

Now the only thing I have left is to actually do it ....

Wish me luck,

Stefano.
 

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Done ... mostly ....

Hello everybody;

so, I sprayed some Deoxit (not really, but the equivalent available at Altronics, http://www.altronics.com.au/index.asp?area=item&id=T3069) on all the trimpots (potentiometers, VR1 through VR6 except VR3, read below) and made some 50 full back and forth swings; same done with the fine speed control, i.e., the front panel user accessible speed control. And yes, the turntable is working ok.

So, in my case that is all is needed; well, not quite.

There is a very high wow and flutter rate and when I touch the front panel speed adjustment control knob the speed varies visibly and w&f accordingly. So, I will replace the potentiometer on next Monday 17/10/2012 and if necessary also the VR1 - VR6 trimpots; hopefully not, because I really would like to avoid to setup the oscilloscope and make the necessary calibrations ...
Finally, I did not spray Deoxit on VR3 as it is sealed and on the service manual says to just turn it fully clockwise and that "in the future" will be replaced with a fixed resistor ... So, I did turn it fully clockwise, as strangely enough it was not!

I am attaching to this last post for now
1) the picture of VR1 (responsible for the 33RPM speed setting) and VR2(responsible for the 45RPM speed setting) after the calibration; you can see is visibly different than what it was before;
2) the picture of the front panel user accessible fine speed control potentiometer, where you can read 1KB; this translates to 1Kohm, linear. This is important, it must be "linear".
3) four pictures of the actual turntable playing an LP from the double album Saturday Night Fever

And, behind the camera .... Me Happy .... (not shown) .... :-) :-) :-)
 

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stefanomollo said:
so, I sprayed some Deoxit (not really, but the equivalent available at Altronics, http://www.altronics.com.au/index.asp?area=item&id=T3069) on all the trimpots (potentiometers, VR1 through VR6 except VR3, read below) and made some 50 full back and forth swings; same done with the fine speed control, i.e., the front panel user accessible speed control. And yes, the turntable is working ok.
Click to expand...

Actually, that cleaner you linked isn’t for cleaning pots, and really shouldn’t be used for that. It’s designed for cleaning printed circuit boards (PCB’s) before soldering, and removing flux from PCB's after soldering. It's pretty nasty stuff, really, that's designed solely for use on the solder side of the board, rather than the component side, where many of the components (e.g. polyester capacitors) will be plastic, or part plastic. It may not be very safe for use with plastic - a lot of PCB cleaners aren't. Having been involved in electronics for a long time (over 30 years), I don't recommend it for cleaning pots, and if you read the Material Safety Data Sheet, it's rather hazardous to your health, whereas most contact cleaners aren't.

Altronics do have cleaners that are safe to use on pots, and that are safe for plastics, including these:

http://www.altronics.com.au/index.asp?area=item&id=T3066
http://www.altronics.com.au/index.asp?area=item&id=T3061

I’ve used the first one, and it’s very good.
 
giancarlopel said:
A little guide to solve the problem:
  1. Open up the turntable and spray a deoxidiser inside the pitch control and 33/45 selector switch; operate repeatedly these controls to facilitate the action of deoxidiser and then wait a few minutes for complete evaporation of the product.
    Sometimes this solves the problem.
  2. If previous operation didn't allow resolution of the problem, then go to check all electrolytic capacitors and replace those that are not in optimal conditions; this obviously requires use of a capacitance/ESR meter.
    If you don't have these tools, then replace all electrolytic capacitors (these electronic components are cheap and easily available).
  3. In my case problem was the presence of a high loss capacitor (C6 - 0,47 μF/25 Volt).
    This faulty capacitor was responsible of a partial short-circuit to ground of the transistor TR3 piloting signal with the consequent failure of the speed control circuit.
    Replacing this capacitor the problem was completely solved.
    To conclude maintenance, I replaced the resistor R15 (= 10 kOhm) with a 12 KOhm resistor and the resistor R16 (= 8,2 kOhm) with a 10 KOhm resistor. The reason for this replacement is that, with the original resistors, the right speed was achieved only by turning trimmers VR1 (33) and VR2 (45) fully counterclockwise (max resistance).
    With this simple change also this problem was completely solved.
P. S.
After repairing is advisable to perform a complete recalibration of the electronic circuit, following the instructions written in the service manual (easily available on the net).
This operation require only a digital multimeter of good quality (currently it's possible purchase one of these instruments with a few Euros/Dollars).
Click to expand...



Hi, I could also fix the same problem (in my case 45RPM was the problem... 33RPM ran right, but I also changed both resistors, just in case)

Replacing C6 changed nothing.

I hope you will read this =)

Thanks!
 
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