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Thread: Acoustic Research 'The Turntable'. A refurb.

  1. #21
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    Quote Originally Posted by TIU View Post
    I can imagine. Thanks for the info Prof.
    If you haven't already done so try some polipods under your plinth, a similar trick made a worthwhile difference to my Clearaudio when I had it, it would go louder before the sound hardened up (feedback loop I mentioned earlier)

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    Quote Originally Posted by The Professor View Post
    ...polipods...
    Sounds more like something you stick in your ears!!!

    I'll go take a look see...

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    Quote Originally Posted by mesavinylnut View Post
    Sounds more like something you stick in your ears!!!

    I'll go take a look see...
    Also look under Foculpods. Around 20 for four large or eight small, I used a Ginko Silver Cloud 11 (one of my customers gave me it, as he had no use for it) which can be simply DIY'd with a few tools, google it, but I've used focul pods to great effect under various non suspended decks from the plinth it's sitting on, mine was on a hifi wall shelf for instance.

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    A little more work done:-

    Motor back in with the addition of an isolation pad, longer screws needed so I tapped out the hole to 4-40. Phase splitter board in and motor wired. Base board nearly finished, just need 2 slots for the mains and phono lead. Will be painted black to hide it!
    Attached Images

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    Checked the Ortofon VMS 20E II cartridge that came off it...still looks good to me.
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    Quote Originally Posted by The Professor View Post
    It's for way more than footfall, play music loud, place hand on plinth, feel vibration, on a rigid deck with a fixed arm board this energy will be transmitted to arm and then cartridge, on my deck I can feel vibration on plinth, but not on platter or armbaord, these vibrations are feedback into cart, amplified and add mush to the sound, so suspension, when done properly is worthwhile.
    The vibration comes from the platter, if I place my hand on it during playback the vibration completely stops!


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    I tried that and the vocal went all weird.

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    Interesting to see you have put the base board on so it sits proud of the body of the table. I removed the corner blocks and replaced them with shorter items that allowed a 12mm MDF base board to sit within the body of the table. This in my view adds to the rigidity of the table while keeping the basic profile I liked so much.

  9. #29
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    Quote Originally Posted by The Professor View Post
    It's for way more than footfall, play music loud, place hand on plinth, feel vibration, on a rigid deck with a fixed arm board this energy will be transmitted to arm and then cartridge, on my deck I can feel vibration on plinth, but not on platter or armbaord, these vibrations are feedback into cart, amplified and add mush to the sound, so suspension, when done properly is worthwhile.

    The new Systemdek came about as I was of the same opinion as you Gary, my previous experience of suspended decks all have compressed springs and usually conical, or the Gyrodek that had suspended springs, but they were conical and too stiff.

    Ramsey Dunlop said when done properly springs make a massive difference, and to prove it he built the prototype that became the 3D it used an O/l platter, bearing and motor, but a new spring system, it pissed all over my Clearaudio Champion level II with magnetic ceramic bearing.

    The production models also have magnetic oil damped bearing and computer controlled AC motor, sound is sublime.

    Spot on Prof!

    "The Voyd" turntable uses three 5mm diameter tension springs, each approximately 25mm long and a wire diameter of 0.6mm. These provide a very soft bounce of low frequency.

    The early Peter Dunlop designed Systemdek also uses three tension springs, but they are much larger than the Voyd at 13mm diameter and 1mm wire diameter and therefore much stronger (higher rate) so the frequency of bounce is higher than the Voyd and also the Pink Triangle Anni.

    The LP12's springs are huge in comparison, but they are also strangely orientated which places the majority tonearm mass on the rear RH side spring so as a result this spring has to be preloaded to a higher rate than the other two causing additional instability which is compounded by the chassis teetering on top of these springs, rather than being suspended below below them which improves stability.
    Last edited by John R; 10th March 2017 at 09:32.

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    Quote Originally Posted by Cable Monkey View Post
    Interesting to see you have put the base board on so it sits proud of the body of the table. I removed the corner blocks and replaced them with shorter items that allowed a 12mm MDF base board to sit within the body of the table. This in my view adds to the rigidity of the table while keeping the basic profile I liked so much.
    I may do that at a later date, need to check clearances inside to be sure.

  11. #31
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    A few parts away with John at AI at the moment, fingers crossed the 'Legend' will be sounding better than ever.

    Pictures in a few weeks....no point rushing a 'master in his art'.

  12. #32
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    Is John not doing it then?

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    Of course he is...AI = Audio Innovation.

    And much in his debt am I to bring this TT back from being a 'shelf ornament'!!!

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    I know, I attempted a bad joke.

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    Quote Originally Posted by TIU View Post
    I know, I attempted a bad joke.
    No worries, I got it.

    Just thankfull I found this forum and John otherwise the Legend would be used as firewood...you'll all see his magic touch in a few weeks.

  16. #36
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    Default New sub chassis design?

    Been playing with some ideas...
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    Last edited by mesavinylnut; 13th May 2017 at 17:24.

  17. #37

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    Something not mentioned so far. PLEASE check the main bearing for slop. The AR 77XB and early 'The Turntable' samples had play in the main bearing which to me, messed with ultimate clarity and 'precision.' The legend version had a bearing re-design and was a superb performer and rather better than it was given credit for at the time.




    As for springs, the mass of the sub chassis and platters is much lower than an LP12 for example, so fitting LP12 springs would raise the bounce frequency dangerously high in terms of stability. I'd have thought the originals would have been fine if they hadn't collapsed
    Turntable bodger, NVA builder and NVA's loan scheme administrator

  18. #38
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    Add stick on lead strips to add mass to the turntable subplatter and platter to see if it improves the sound - it is not expensive to buy and comes in lots of different widths (do an ebay search) - here is one example http://www.ebay.co.uk/itm/12mm-Self-...AAAOSwoudW5oE~. It has the added advantage of damping the platter as well as adding mass ..
    A good earwash may be the cheapest and best upgrade to your system.

  19. #39
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    I'm holding off on the pictures until all the work is done...then I'll show her in all her glory.

    Just a new phono lead to procure and that's it...so close now, can't wait to start spinning a few vinyls!

  20. #40

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    heres my 2 pence worth,
    leave the springs alone,i tried the linn/Vinyl Nirvana springs and they ruined it,too stiff,you need to add mass loading to get them to work,which is a waste of time imo.
    the best sonic upgrades i found was changing the stock mush tonearm board and using one made of ebony,it made a big difference,i also used some lead roofing flashing to damp the underside of the platter.

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