Turntable repair question

Discussion in 'GENERAL AV Discussions' started by 96cobra10101, Mar 17, 2013.

  1. 96cobra10101 Senior Audioholic

    96cobra10101
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    I have a Micro Seiki MB-18 turntable I bought back in the 1990's at an estate sale. I got it cheap as it needed a cart, but it spun and was in decent shape. I never used it, and it has lived in a closet since its purchase. Jump forward 20 years, I installed a new cart on it and I noticed that the counter weight is not the correct counter weight, in fact it is something that has been Jerry-rigged. So what to do. Can I get a different tone arm for it or maybe a counter weight that is correct to make this a working turntable? I hate to discard it, even though it's a budget table. I don't want to invest much into it since it is an inexpensive TT. My goal was to set it up with my old Sansui receiver and my Teac tape deck with some old Kenwood speakers in my office.
  2. macddmac Audioholic General

    macddmac
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    I would pm TLS guy, hey seems to be very knowledgable re: well, everything :)
  3. 96cobra10101 Senior Audioholic

    96cobra10101
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    Bump
    bump
    bump
  4. Grador Audioholic Field Marshall

    Grador
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    Even if the counterweight is jerryrigged is the tracking force correct? Could be perfectly usable.
  5. TLS Guy Audioholic Overlord

    TLS Guy
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    Good photographs of the turntable in its current state would be helpful, especially pics of the rigged counter weight.

    Since it does not have the original counterweight, you will need one of these.

    Now if the current system will allow the arm to balance in the neutral position and then allow setting of the correct tracking force with the gauge, that is most of the battle. However the counter weight must be decoupled from the arm, by a spongy rubber bushing between the counter weight and the arm.
  6. 96cobra10101 Senior Audioholic

    96cobra10101
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    Here are some pics
    2013-03-18 20.18.50.jpg
    2013-03-18 20.19.12.jpg
    2013-03-18 20.19.00.jpg
    My "good" rig
    2013-03-18 20.19.51(1).jpg
    which currently isn't hooked up because my room is still not built out yet and looks like this
    2013-03-18 20.22.16.jpg
  7. Grador Audioholic Field Marshall

    Grador
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    Out of curiosity, why is this?
  8. TLS Guy Audioholic Overlord

    TLS Guy
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    Actually not all arms need a decoupled counter weight. However most pickup arms are highly problematic.

    The type of tube arm in the turntable in question with detachable arm really sing in the 200 to 300 Hz range. Decoupling the counter weight helps lower the Q of this resonance.

    Basically moving magnet high compliance cartridges need low mass, low inertia tone arms.

    The highly touted very expensive moving coilh medium compliance cartridges need higher mass tone arms.

    Turntables are much more complex than they seem. The arm cartridge combination is critical. Almost always there is serious mismatch compromising performance. Ideally the arm and cartridge should be designed as a unit like the old Decca ffss arms and cartridges.

    [​IMG]

    The SME series III arms were designed with the Shure V 15 series cartridges in mind.

    I think the best moving magnet cartridges outperform the expensive moving coils.

    In my view the Shure V15 xmr was the finest cartridge ever produced. To really optimize this cartridge it needs to be mounted in an SME series III arm with the correct damper in the silicone fluid bath.

    I think a Shure V 15 V 15 xmr correctly set up on a SME series III arm and a good turntable gives the best results it is possible to get from LPs. It is way ahead of the pack.

    Visitors are astonished at the LP quality here. It occurs because of the selection of the correct equipment.

    If you want to get the best from modern moving coil cartridges then you need an SME V series arm. These do not have or need a decoupled counter weight, and in fact should not have one.

    Turntables and cartridges are a definite area where paying a lot more for the right equipment pays dividends.

    To find a good used Thorens TD 125 and an SME series III and a Shure V 15 xme will cost you a pretty penny, but in my view that is as good as it gets. The first two items are not hard to find, but the Shure is. However the Ortofon Black moving magneth is very close to the spec of the Shure and is a very good alternative.
  9. 96cobra10101 Senior Audioholic

    96cobra10101
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    Not wanting to blow a wad of cash on this turntable, just get it setup better than what it is, what do you suggest?
  10. TLS Guy Audioholic Overlord

    TLS Guy
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    Hard to know without having the unit in front of me. But your essential equipment is the stylus force gauge I linked so you can set the correct tracking force. You will need an alignment protractor to correctly set the tracking angle. You can download one free form the Vinyl Engine.

    It looks from the pictures that there is a soft bushing between the arm tube and the counter weight. Is that correct? If that is so, then after that you are home free.

    You won't spend a wad of cash, as you will not find the parts. This restoration will be down to skill and creativity.
    • Like Like x 1
  11. 96cobra10101 Senior Audioholic

    96cobra10101
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    I have a gauge for tracking force. The soft bushing is velcro, and the weight is a piece of hollow metal. If I were to keep this counter weight, what else can you think of that could be used as a soft bushing? It just odd to me that the weight is missing because the rig itself is in really great shape.
  12. TLS Guy Audioholic Overlord

    TLS Guy
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    The Velcro may well be enough to do the trick. The question is, can you set the tracking force correctly?

    If you can, I would leave it alone and set the tracking angle correctly with the alignment protractor.

    If you can't set the tracking force correctly, this is when you go your parts bins and hardware stores etc, in search of what my father used to call "A sort of a sortofer."

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