I was visiting a friend recently, chatting to his father, Neil, who is very ill. I saw that his cherished Thorens TD-125 Mark 2 was languishing, non-functional, in a pile of dust and dirt.
The Thorens clearly hadn’t been operational in a long time and when Neil expressed disappointment that he wasn’t able to play his records any more, I decided to completely repair and restore it for him, hopefully finding the fault that had put it in the corner in the first place.
I have a basic plan I stick to with restorations like this one. It involves first stripping the deck of all large parts and setting them aside for cleaning. In this case I removed the lid, platter and mat.
I then use a special foaming cleaner to remove dirt, dust, cigarette residue and grease from every component. This is a slow process but yields great results. I also usually wash rubber mats in a mild detergent solution in warm water.
With all this done, I cleaned away the residue from the old and perished rubber belt. The old belt had broken down, leaving bits stuck to the pulley and hub that the platter sits upon. I also carefully cleaned the tonearm and re-tensioned all the screws and fasteners I could easily gain access to.
Next up was to diagnose why the deck didn’t work. I checked the power supply and found that I had rails, but two larger electrolytic capacitors in the motor drive circuit had died and this meant that the motor would not run. I replaced these and sure enough, the motor now turned.
Next step was to clean and re-lubricate the spindle bearing and any other mechanical bits that needed it. On a deck of this age, it’s likely that the spindle won’t have been re-lubed EVER and this was apparent when I removed the hub from the deck. The bearing was completely dry, so I cleaned the bearing and bearing well and added the correct amount of my special synthetic turntable bearing oil.
Next I rigged the deck up with a new belt, replaced the platter and started the function testing and adjustment of rotational speeds. Motor phasing adjustment is critical in these decks. It sets the correct drive speeds and more importantly, minimises noise and vibration from the motor. This step is critically important or the motor won’t run smoothly.
Luckily the service manual explains the process fairly clearly, but you need an accurate DMM and some previous experience in working with electronics or you could really cause some problems by attempting this. I soldered some wires to the test points in order to maintain a good connection with them whilst juggling the deck, a screwdriver and watching the DMM.
Almost done, I restored the strobe assembly, which was cloudy and not correctly aligned. To do this, I stripped the assembly and cleaned each component, before reassembling the parts and checking their alignment. Alignment is set with the platter and mat attached, as loading the suspension changes the alignment. Patience is needed here.
The final jobs were to carefully clean the stylus assembly of the original Shure V15 Mark 3 and align the cartridge correctly in the gorgeous SME Series 3 tonearm. I adjusted all aspects of the tonearm, which was not well setup for the cartridge it was carrying. This was likely the result of my buddy and I partying too much all those years ago when we used to use Neil’s equipment in the basement of their old house.
Anyway, the Thorens TD-125 performed absolutely beautifully once restored and now looks a million bucks. Neil told me just how thrilled he was with the result and he can now enjoy all his records once again.