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  • Matt Rector

    Audiophile Sound Systems Music and More

    Rebirth of a Legend – The restoration of a Thorens TD 125

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    • Rebirth of a Legend – The restoration of a Thorens TD 125

    I have worked on lots of turntables so I have my preferences but I am hard pressed to think of a better built TT than the Thorens TD 125 MK II.


    When I first put a turntable on my bench the first thing I do is assess what’s working, what isn’t and whether DSCN2102it is worth my time to fix or go into my parts locker. Fortunately, this TD 125 was in great shape cosmetically (other than dirty as hell) so I was stoked when I plugged it in and the motor turned and tached on speed right off the bat. But of course there were issues as soon as I touched the speed control things started going haywire but that’s pretty standard for 40+ year old potentiometers so the process began.

    To get to the speed potentiometer I had to remove the top deck, the switch covers and the front aluminum panel. With all of that off it was easy to get the tip of spray tube in the slot so that I could fire in some Deoxit F5 for faders. As far as I could tell this is a plastic on plastic potentiometer so the fader spray did the job perfectly.

    Next it was time to work on the rather unique power supply speed regulator board. It has two big 1000uf capacitors on it and as I suspected they were way out of compliance. They should have an ESR of less than .1 and they were reading .4 and .6 so while they are doing their job now once someone started using this DSCN2103on a regular basis they would fail soon and probably do some extra damage on their way out. Of course they were axial caps and the ones I wanted to use were radial but this par for the course with electronics of this generation so I’m use to finding ways to make it work. In this case I stould them up under a support board which worked out perfect. Because of the way I had to fit them I couldn’t glue them down but I wanted to secure them so that in transit they wouldn’t have undue stress put on the solder joint and a little electrical tape around the support bar and the caps did the job perfectly.

    Now it was time to set the voltages on the nine variable resistors so first I cleaned deoxidized and lubed them thoroughly and went through the process and reinstalled the board. Once I’ve got it all back together I’ll run it for a few hours and then go back and reset them all.


    With it all apart I totally cleanedDSCN2107 the subplate. First I dusted it, then Windex and a rag, then a tooth brush and q tips and then another round. 40+ years of dust, dirt and grime take a while to get off. I then took apart and cleaned the strobe mechanism but unfortunately when I put it back together the tiny bit of spot rust on the black piece of spring metal looked the size of an elephant through the prism so back apart it came. A little sanding a few coats of Rustoleum Gloss Black and it was perfect. Once it was dry and everything was put back together it looked fantastic. I also replaced the foam strip on the strobe panel. So I went about cleaning the aluminum panel and switch covers and put it all back together.

      Top Plate

    If the subplate didn’t impress with its 14 gauge Galvanized sheet then the massive aluminum top plate has to. The thing is just a beast and must weigh at least five pounds all by itself. To reinstall it you have to put the deck on its side, put the springs in the spring cups and push iDSCN2106n while holding it in position then put the rubber grommet washer and nut on. Fortunately I was well prepared and had all of the parts laid out so I could grab them without looking. It takes a little fiddling but as long as your careful it all goes together fairly easily and there is no finicky suspension adjustments like on a Linn LP 12. Before I put it back together I cleaned the underside and edges. With the top plate inDSCN2110 place more cleaning commenced until it was spotless. The last thing I needed to do was reglue the foil label.

    In the next installment I’ll recondition the tonearm board, the SME 3009 tonearm and dial it all in.