Turntable Platter Wobble

Discussion in 'Vinyl Nutjob World: Turntable and Related Gear' started by mrflibble, Feb 1, 2017.

  1. mrflibble

    mrflibble Friend

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    I asked this question in the General Advice Thread, but it is probably better to ask here.

    Is it normal or within tolerances for a turntable platter to undulate / wobble a small amount? I ask because I recently acquired a refurbished Technics SL1210 and the platter undulates slighty, perhaps 1-2mm in the vertical. One can see the cartridge bob up and down, this is much less noticeable arms moves towards the centre. Should I expect the platter to be dead level?

    I performed a test recording and the waveform exhibits a steady 7.5Hz (45rpm) wave which I assume corresponds to the wobble so its not just my imagination.

    Many thanks.
     
  2. purr1n

    purr1n Desire for betterer is endless.

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    Definitely not normal. You should not be able to perceive any wobble.
     
  3. Serious

    Serious Inquisitive Frequency Response Plot

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    The 7.5Hz sine is most likely the tonearm-system resonance, but the wobble shouldn't be there.
     
  4. mrflibble

    mrflibble Friend

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    Thanks Guys. I will do some investigating and contact the person I bought it from.
     
  5. powermatic

    powermatic Friend

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    First, grab the spindle between your thumb and finger, and rock it back and forth to see if there's any play, which could be a sign that one or more of the three screws holding the spindle down to the deck are loose. If all seems solid, pull the mat, put a finger in each hole in the platter, and gently rock to see if it's secured to the spindle. All good so far? Then visually (or with a piece of tape) note the orientation of the platter relative to the plinth, put your fingers back in the platter holes, thumbs on top of the spindle, and 'squeeze' the platter off of the spindle. If it doesn't release, it's a two man job, where one person pulls the platter, number two holds down the plinth and GENTLY taps the spindle with a nylon mallet, block of wood, etc. causing the platter to release. You'll see that the spindle/platter interface is a simple tapered brass cone. Check it for any obvious nicks/dents/deformations-these decks, nice as they are, often had a rough life. Now spin the platter 90/180 degrees distant from your initial look, and press the platter with some gentle firmness back on to the spindle, start it up and check the run-out. I'm sure you're getting the idea by now, you're trying to find the spot on the spindle that eliminates/minimizes any inconsistencies in the mating of the platter and the spindle. Or maybe it just wasn't put together correctly during the 'refurbishment'.

    There are only three possible things that can be at fault: loose spindle screws, damaged spindle, damaged platter. A new spindle is available (https://www.kabusa.com/frameset.htm?/m1200.htm, for instance) but I'm guessing it's something a lot more simple than that. Let us know what you find!

    Edit: forgot to mention that there is a bit of built-in vertical movement in the spindle/bearing assembly, so be aware of this, and apply some pressure down while doing the 'rocking movement' diagnosis.
     
    Last edited: Feb 1, 2017
  6. mrflibble

    mrflibble Friend

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    Thanks powermatic. I've gone ahead and tried that. I think the spindle looks a little worn, but I'm not sure what I'm looking for as I am somewhat of a noob when it comes to vinyl. I've taken some pictures of the spindle and the platter and I have made a very exciting movie:

    https://drive.google.com/open?id=0B5Txh-8tLqixeWI5ZVB6Vi1mZ3M

    The mat is a Funk Firm Anchromat, it is 5mm deep. The turntable was setup with the Technics felt mat, I have not re-adjusted the VTA for the new mat.

    Please forget what I said about the sine wave, I was a factor of 10 out with that! Shouldn't do math when I am tired :oops:

    Many thanks
     
  7. mrflibble

    mrflibble Friend

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    Any opinions on the photos or movie? The photos were taken with the flash, so they are a bit more contrasty than real life. To me, the spindle does not look great. I didn't check if it felt rough. I will have a closer look for dents etc, the daylight is a bit better today.

    @powermatic The platter seemed solid and secured to the spindle when I attempted to rock it. I replaced the platter at a different angle but it did not make any difference to the wobble. But I will check again today.
     
  8. mrflibble

    mrflibble Friend

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    Actually, there is a little play when rocking the platter but that seems reasonable? The three screws are tight.

    I felt the spindle and despite not looking great I could not feel any roughness.
     
  9. mrflibble

    mrflibble Friend

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    Good news, I contacted the seller and he says that it is not right. He is going to change the spindle and / or platter.
     
  10. powermatic

    powermatic Friend

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    Oops, sorry I didn't get back, I tried to open your photos yesterday but for whatever reason they wouldn't appear. Virtually any visible run-out (wobble) is unacceptable on that deck, so you're right to be concerned. Sorry none of my healing attempts helped, but good to hear that your seller is standing beside you, fighting the good fight. These are good turntables, even with the stock arm. There are lots of upgrades available also, though I'm not sure many of them make economic sense. Here is what I did to my $150.00/broken tonearm/basket case, which made no sense from either an economic nor time perspective, but was still fun:

    [​IMG]

    [​IMG]

    I separated the power supply, eliminated the 'pitch slider', and obviously the new plinth. Most important sonically, of course, was Mack The Bulldog Record Weight. :rolleyes: Again, don't do any of this-you can buy an SP-10 for a bit over 1k U.S.!
     
  11. Thad E Ginathom

    Thad E Ginathom Friend

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    My Dual turntable has always done this. Sadly, I didn't have the sense to take it back the same day I bought it! I certainly should have.

    Whether it is fixable or not I do not know. Last time I tried to take the platter off (for a house move) I could not, and yes, the method is just to lift it. But pros have their tricks, as @powermatic describes above.

    When ever I see our local repair wizzard (works under a local Philips umbrella; last month he put new rechargable batteries in my ancient Philishave) he asks when I am going to take my deck in. One day I will. For starters, there's 26 years of cat hair inside that thing!

    But getting around to it is the thing, having gone pure digital. Even though a house without a turntable feels sort-of empty :(
     
  12. mrflibble

    mrflibble Friend

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    The guy came round today to look at the turntable. He had a new platter and spindle with him. But after inspecting the platter and pressing on the edge he managed to get the vertical displacement of the platter down to be somewhere between 0.5 and 1mm (I've eyed it up with a ruler). He said it wouldn't get any better than that and no point replacing the spindle or platter. But it still looks more wobbly when playing a record.

    Are my expectations of the SL1200 / SL1210 too high? I know @Marvey said they shouldn't be any perceivable wobble, but maybe I'm being anal?

    I can hear a beat through the headphones at the start of the record, that is in time with the rotation.

    With the mat on the wobble looks worse, it seems to amplify the wobble, The mat doesn't seem to sit completely flat. I put a record directly on the platter without a mat (just to test) and powered it at 45rpm and that seems to amplify the wobble also. It's not a good idea to put a record directly on the platter, it does't stop when the platter stops!

    I think there is some imperfection on top of the platter rim in addition to the 0.5mm + displacement that makes it worse when actually playing a record.

    I dunno, I'm not very happy. I spent more that I should on the turntable because the guy was local and the mat cost an arm and leg too. :-(
     
  13. Thad E Ginathom

    Thad E Ginathom Friend

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    If you are going to listen to records on a turntable, you have to be either seriously anal or, "WTF is all the fuss about? This is just the way I've always played music!"

    :pirate07:
     
  14. Dino

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    I'm more in the second camp, @Thad E Ginathom. I find what I am reading about optimizing computer/pi digital playback way more complicated that I ever found record care/playback.
     
  15. Mr.Sneis

    Mr.Sneis Friend

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    Platter mats can have some imperfection to them though they shouldn't. A technics table like that (without suspension) should have no wobble to the platter no way no how; you can't just tweak it out and call it a day. Seems to me the spindle got tweaked in transit and is causing the platter to be out of kilter?

    Usually you separate the platter from the table if you transport it around for this very reason.
     
  16. Dino

    Dino Friend

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    I have no experience with the SL1200 / SL1210. I have only had belt drive turntables. I have never experienced platter wobble and I have been at this since the early 1970s. Platter wobble would seem wrong every time I played a record. That would really bug me.

    I don't think the seller is "anal" enough.
     
  17. mrflibble

    mrflibble Friend

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    I was referring to myself as possibly being anal, not the seller. It seems, however, that I am not anal.
     
  18. Dino

    Dino Friend

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    Yeah, I got that. :) I was meaning that the seller seems like he is blowing your problem off.

    Edit: And he came out with a platter and spindle that could have solved the wobble and chose not to try.
     
  19. mrflibble

    mrflibble Friend

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    I've run my finger around the lip and there definitely seems to be a short length that is a tiny bit raised. It is hardly perceivable, but it would explain why the mat doesn't sit completely flat and why the wobble is worse with the mat and / or record are on the platter.

    These small imperfections add up and are magnified at the edge of the record.

    I'm going to ask the seller for a refund minus his time and trouble. I'm not very happy today, feeling fed up with things unrelated to hi-fi :(
     
  20. Thad E Ginathom

    Thad E Ginathom Friend

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    I think that, as a buyer, you should be happy with your purchase. Joking aside, it is not anal to seek to know the acceptable tolerances for something like this.
    <crossposted>
    If the platter alone is sufficiently true, then you might, if you really want this turntable, consider simply replacing the mat. It might be easier than starting the process of looking for another seller.

    But if you are saying that the platter is imperfect, I think you are probably right to call the deal off.

    Having said that, let me repeat that mine is much worse, was from new, I should have taken it back --- but I still had many, many hours of music listening from it. But it is a buying mistake I wouldn't make again.

    Sorry for your unhappiness. Hope things are brighter tomorrow.
     
    Last edited: Feb 10, 2017

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