Speed fluctuations and skipping on Pioneer pl12d

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Lord Alfreston
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Speed fluctuations and skipping on Pioneer pl12d

Post by Lord Alfreston » 15 Apr 2019 22:37

I bought my daughter a Pioneer pl12d turntable second hand. She’s in London I’m in Cornwall. The arm lifting mechanism seems to be sticking and stopping the arm from lowering properly onto the record if it’s been left for 24 hours or so. It then sounds terrible, plays the same groove again and then skims backwards off the record. It seems to then work again. It has also started speed fluctuations making the record sound wonky.Could it need a new belt? I have attached links to some YouTube videos she sent me. You’ll have to cut and paste into browser to see them. Any advice gratefully received!

https://youtu.be/x6PQ3USqVc8
https://youtu.be/xAdmmyAiKxg

musicmn
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Re: Speed fluctuations and skipping on Pioneer pl12d

Post by musicmn » 16 Apr 2019 01:35

Hi, it sounds like the turntable could just use a good servicing and a new belt. The speed fluctuations could be caused by the fact that the bearings in the motor are now dry and in need of fresh oil. The spindle should be removed from the housing, then cleaned and fresh lubrication put in. The cue mechanism which slowly lowers the tonearm to the record sounds like it also needs to be taken apart. Then cleaned and new silicone damping fluid put back in. All this and a little more should be done at this time if this turntable has never been serviced. The fact is that this turntable is over 40 yrs old now and it's just the age that's catching up to it. I hope this helps.

KentT
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Re: Speed fluctuations and skipping on Pioneer pl12d

Post by KentT » 16 Apr 2019 04:45

New belt, cleaning the inner platter, and motor pulley, and lubrication with good 20W machine oil (And training your daughter on basic turntable maintenance) will pay dividends (also bear in mind Pioneer in the manuals, expected the motor to be lubricated every 3 months). This said, an opportunity to share knowledge, to educate, to help keep this classic alive, and make music. And spend time with your daughter. Cherish this, enjoy this, pass down some knowledge, Quality time for multiple generations, you'll enjoy this too,

vanakaru
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Re: Speed fluctuations and skipping on Pioneer pl12d

Post by vanakaru » 16 Apr 2019 08:39

I got this TT recently. It does sound very good indeed.
Fortunate for you it is very simple design and not too intimidating to service. Mine works with old belt at stable speed but the motor needed just a drop of oil. So do the motor first. However I would buy new belt for it for sure.
Platter bearing must be cleaned and re-lubed - it took me few minutes - without belt installed the platter should turn freely for a minute or so(maybe more). If the bearing is good then the platter does not stop abruptly in the end but gradually slows down to smooth halt. There is a ball in bottom of the bearing well. I used strong magnet attached to the screw driver to fish it out. If it shows sign of wear replace it. You can check the ball by placing it on the glass - if it rolls freely in any direction its OK - just don't loose it in the process. Bearing well could be cleaned with alcohol and q-tip. Just make sure you do not leave lint behind. I put the ball on the shaft with a stab of grease, fill the well with oil and slowly press the shaft down to the well letting excess oil to drip out(don't make a mess, have something under the bearing).
plays the same groove again and then skims backwards off the record
Check the arm. Make sure your TT is levelled. Make sure you have right stylus pressure and anti-skating set.
https://www.youtube.com/watch?v=jVzpSBO ... gs=pl%2Cwn

cre009
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Re: Speed fluctuations and skipping on Pioneer pl12d

Post by cre009 » 16 Apr 2019 10:20

There is an extensive maintenance guide here

https://mr-ives.blogspot.com/2013/07/re ... table.html

The problem for the OP may be that the arm lift mechanism may require some silicon grease to be applied.

Lord Alfreston
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Re: Speed fluctuations and skipping on Pioneer pl12d

Post by Lord Alfreston » 17 Apr 2019 18:26

Thanks all for your very helpful replies. Now all I have to do is guide my daughter from hundreds of miles away! She enjoys getting her hands dirty tho'!

letter109
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Re: Speed fluctuations and skipping on Pioneer pl12d

Post by letter109 » 10 Jun 2019 05:20

Hi all...I've had several Pioneer PL-12-type turntables come through our shop, and they have invariably run fast. Usually they are running a little fast when I get them, and after I clean and lube them, they are running even faster still. Over the years, I have looked high and low for any real advice about how to address the speed issue on the PL-12 and similar decks, and the only thing I've ever found is that buying the proper belt and making sure it is riding the wide part of the pulley is the only solution. Of course, the "proper belt" seems to only be obtainable from Thakker over in Germany, which is a shop I actually use quite often for other stuff. In the past, I have bought the belt from Thakker, installed it on PL-12s and 112s, etc. (anything with the synchronous AC motor) and I still have speeds anywhere from 34-36 RPM. So, what I keep finding is that the fix everyone says will work never works for me...and I've had this experience so many times now, that I am beginning to think the folks who say they fixed their PL-12 by buying the correct belt are simply not telling the truth, but they say their problem is solved anyway because that's what you're supposed to say in the VinylEngine forums.

Here's what I do now when a Pioneer PL-12 comes in the door, and you all may crucify me as you see fit...in order to get the speed right, first I clean and lubricate the deck, and then I buy a new 23.6" belt. I install it and I run it for one hour. Then I put a strobe disc on it, and it is running fast still, always. So, then I get a small piece of 400 grit black sandpaper and gently reduce the diameter of the pulley by dragging the sandpaper lightly around the pulley while it is running at speed. Takes about 45 minutes to so this, because this is a one-way trip and if you go too far, it's time to buy a new pulley. I have cured seven Pioneer PL-12-type decks this way and never had a complaint about it from anyone who's bought one of mine. And by golly, those decks run at 33.3 RPM when they go out the door, and they stay that way.

Now the only question I still have is, were the Pioneer PL-12s all born with motors that run too fast or has their speed gradually increased over the years as a result of some alchemy of hysteresis? I never had a problem with Garrard for BSR decks that use AC synchronous motors, so why Pioneer I wonder?

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