2SL-120L

Technics SL-120 Direct-Drive Turntable Restoration

I was recently asked to undertake the restoration of a lovely old Technics SL-120 direct-drive turntable. The SL-120 was basically an SL-1200, without a tonearm. Owners often chose to fit an SME 3009, as was the case with this old deck. This one though, had seen better days…

The Technics SL-120 is a quality direct-drive deck, featuring an ultra-low speed brushless DC motor. This gives it several notable advantages over belt-drive decks: no belt or transmission to introduce noise and irregularities of motion, a motor that is ultimately locked to a quartz crystal, meaning the deck is not subject to mains fluctuations as AC motor belt-driven decks are, and direct coupling of the platter to the motor, given that the platter and motor rotor are one part!

The SL-120 is not quite as heavily-built as the SL-1200, but nevertheless this is a solid deck, weighing in at 10 kg, with 1.75 kg of platter mass, just like the SL-1200. The deck features a strobe, with vernier speed adjustments possible via small knobs at the front left of the chassis. Speed change is effected by a lever.

This particular SL-120 exhibited several issues, notably the SME 3009 arm was in very poor shape with almost everything loose, broken or misadjusted. The motor bearing was dry and desperately in need of some oil. The chassis was also filthy and the lid was not attached properly at the back and the speed controls were not working properly, and were very stiff. the strobe seemed to be operating only intermittently as well.

Basically I fixed the headshell wires and resoldered a couple of cartridge clips. I thoroughly cleaned the arm as you will see in the photos and attached a nice new Ortofon 2M red cartridge. I opened her up and cleaned the speed adjustment pots, speed switch, cleaned the whole chassis and lubed the motor.

In relation to the SME 3009, some work was required there and this needs to be factored in if you are planning similar work yourself. Soldering cartridge clips requires a fine soldering iron, a low – moderate tip temperature and a very steady hand, along with an ‘assistant’ in the form of a small vice or soldering assistant. 

In terms of the mechanical components of the arm, almost everything is adjustable on the 3009, and most of these adjustments will be set up incorrectly in my experience. You have to set the lateral balance, stylus downforce, anti skate, damping paddle, arm ride height and arm travel along the arm mounting plate. All of this must be set precisely, in order to extract maximum performance from this venerable tonearm.

After working through the issues, the SL-120 came up beautifully and her owner was very happy. I can certainly recommend the technics SL-120 as a great mid-range deck, that should give years of reliable service and offer many advantages over cheap new belt-drive decks.

If you want more reading on the Technics SL-120, or the owner’s or service manuals, visit the Vinyl Engine!

 

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Nice smoked acrylic cover on these old girls with room left for raising tonearm and the location of the pivot assembly.
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deck as delivered to me. Note broken cartridge clips and general dirty state of deck.
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Close-up of those pesky cartridge clips…
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Dirty SME 3009, missing her anti-skate weight. The stylus pressure weight is actually sitting off to one side. The arm must be removed to properly clean her and sort out those headshell wires.
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And this is how you achieve that!
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SME arm removed and you can see the rubber gasket that the arm board sits on, a nice touch by Technics.
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Foul!
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Years of gunk must be removed…
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The damping paddle that traverses this silicone oil bath must also be adjusted.
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Look at the difference after cleaning! The arm is gleaming now.

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She looks as good as new.
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Time now to sort out those speed controls and intermittent strobe…
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Here we see the logic and motor drive board front and centre, transformer to the right rear, and speed controls and strobe right front.
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These must be carefully cleaned..
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Finished deck, with new Ortofon 2M Red cartridge and fixed wiring, running and sounding as good as new!

11 thoughts on “Technics SL-120 Direct-Drive Turntable Restoration”

    1. Hi Greg
      goldenageaudio.com.au appears the best bet over here Greg from what I’ve heard. I haven’t got round to using him so this is based on advice I’ve received.
      He definitely services Vintage Decks including Technics. He gets very positive feedback on Stereonet, that’s he’s reasonably priced and knows his stuff. His website gives you some idea of his capabilities and you can contact him if you want to ask him specific questions.
      An alternative over here is CVE electronics based in Coburg who service and recalibrate later model Technics the 1200s mainly but they may be worth a shot also. They did an upgrade fitting some Burson Op amps into a CD player of mine some time back. I couldn’t fault them and Burson Audio were happy to recommend them on their website.
      Hope this is of some help.
      Happy New Year to you and hope work is going well.
      Regards,
      Peter.

  1. Very interesting article. I have two SL120s. The one I use has difficulties with speed and probably hasn’t been serviced properly in many years if ever. I’d love to get it working properly. I’ve got a Micro 505 tone arm on it and when it goes right it sounds pretty good with a nice punchy sound.
    Peter.

      1. Hi Mike, I live outside of Melbourne. Am happy to ship it to you if you are ok with this.
        Regards,
        Peter.

      2. Hi Peter, I generally discourage owners from ever shipping turntables anywhere to be honest as shipping can often result in damage. I like people to hand deliver fragile turntables to me and I’d suggest that there might be someone local who can assist perhaps?

      3. Hi Mike not sure if I deleted my reply to you or not. Thanks for the feedback. I appreciate the risk issues in turntable carriage and your position regarding this.
        However I was taken by your work on the turntable as I had previously advise the speed issues were too difficult to fix.
        So if you are willing I am happy to ship and accept the risk without reservation.
        I would remove the arm and the platter.
        Anyway It’s your call and I will respect your decision.
        PS great article on the Yamaha speakers!

      4. Hi Peter, thanks for your kind words and whilst I appreciate that you would probably pack the deck well, I still think it best if you can physically take the deck to someone and avoid shipping at all costs. Unless you happen to have all the original packaging its best avoided and even then its a risky thing!

  2. Mike, how would you rate the SL-120 vs the Kenwood 500 and 600 in terms of the long-term serviceability of their innards and overall quality? Discrete components throughout that are easy to source if replacements are required, so I hear? There is an SL-120 advertised at present in pristine condition, but it is pricey. One does have to make up one’s mind quickly when one of these direct drive ‘classics’ such as the Kenwoods or Technics appears on the market. I’m not in a hurry, though, since my Akai AP-006, of similar vintage, is sounding better than ever with recent upgrades. I’ve owned it for 35 years, and will certainly keep it for everyday use if I get an up-scale classic for ‘best’.

    1. Hi Selwyn, the KD-600/650 is the best of the bunch, no question. The KD-500 and SL-120 are on par, with the Kenwood being better built. All are quite serviceable, best bet is to grab any of them without thinking when in excellent to mint condition. You can’t lose money on quality decks like these if buying at sensible prices. Cheers, Mike.

Thanks for reading, leave a comment and let me know what you think!