Thorens TD-124/II restoration / upgrade

I’ve been doing the motor rebuild today as the new oil arrived yesterday. I did decide to try the original bushings again as I think they are perfectly good and do seem a slightly freer and easier fit on the motor spindle without being even slightly ‘loose’. Most of this thread is basically a giant rabbit hole I ended up descending purely due to dreadful modern ‘too tight’ belts. If I was starting again with a new 124 today in similar (very, very good) condition I’d do far less. I basically went chasing the wrong things as I didn’t believe an expensive highly-rated new belt was the cause of my noise issues. I’m currently at the deck standing on baked bean cans whilst I painstakingly adjust the motor housing. I’ve got it pretty good, it is nice and quiet. I’ll leave it running for a few hours and then give it a final nudge or two.

I’ve only taken one new picture as everything else I know is already covered upthread:



This is how I vacuum-load sintered bearings. Chuck them in a syringe. Replace the plunger and then load the syringe with oil until it just covers the bushings. Then block the hole with a finger and pull the plunger right back creating a vacuum. The bushings start ‘fizzing’ quite violently as the air is sucked out of the pores and is replaced with oil. Just keep repeating expelling any air from the syringe and recreating the vacuum until there are no more bubbles to suck out of the bushings. It is cheap and it works!

The oil seems kind of a mid-point between the very thin Schopper stuff and whatever I was using. I don’t think I’ll be getting the crazy long spin-down I did with the former (it’s about 15 seconds at present, I had over 30 with the Schopper, but I’m pretty convinced that’s just a marketing metric. If there was a proper Thorens service figure I’d spend hours trying to hit it, but I don’t think such a thing exists. This new oil is an equivalent to what Thorens used, so I assume it is about right! I’ll be interested to see where I end up with regarding speed-drift.

 

20 second unloaded motor spin-down after a good warm up. I’ll take that. The deck is back together and playing fine, some Mogwai as it happens. I won’t know where I am with regards to speed stability until I’ve tried a few cold starts. FWIW rebuilt and with a warm motor my default fine pitch setting (set for a warm deck) was still pretty much bang on despite the complete rebuild and oil change. I changed the (Schopper) main bearing lube to the Mobil stuff too while I had it out of the deck.

 

Ah, maybe I should have taken a pic of that! The motor is suspended under the chassis. You need access to it as the three main parts of the motor casing need very careful alignment for quietest running. This is quite fiddly and is far easier to do this with the deck removed from its plinth and standing quite high off the table on a suitable support, in my case the baked bean cans. It gives good physical and visual access to the motor and leaves enough space to get a small screwdriver to the motor case screws. Just think of it as using jacks or a hydraulic stand to get access to the underneath of a car. Same logic.

 

Reading it back I missed out the word ‘stage’ from that sentence which made it read rather strangely.

PS Just tried a cold start (deck last used best part of three hours ago), and it has come straight up to 33.37rpm according to the RPM app. If this remains the case it is the best I’ve ever had by far. That’s within a rounding error of the fully warmed-up speed I was getting earlier, i.e. within mains fluctuations etc. My last build with the tape deck oil and Audio Silente bushings started about an rpm slow and hit speed after a 45 minutes or so warm-up. The Schopper oil I used years ago started quite a bit fast and eventually slowed down. Obviously I need a lot more run-time and testing before knowing exactly what it is doing, but this is certainly pretty promising. I should really try the Audio Silente bushings with this oil, but to be honest I can’t be arsed if its working. I’ll clean them thoroughly and keep them as spares for the future.

 

Very happy with this oil and motor rebuild so far. Hardly any speed drift at all from cold to warm. This, the new lower-tension belt and the Retrotone upper platter has this 124 performing the best it ever has. It is really sounding good; quiet, dynamic, and rock-solid pitch and timing.

 

As a result of another thread warning about decaying old wire coatings and the dreaded ‘green goo’ I decided to check my TD-124/II. I’d previously noticed the wiring was a bit sticky and nasty, but I’d put it down to an oil spill at some point in the turntable’s life. It didn’t even occur to me the wire itself was decomposing and reacting with the copper. It was, very obviously.

On this 124 this was pretty much limited to the two pieces of black two-core cable that connect the mains input to the voltage selector, mains switch, and strobe neon bulb. This cabling was absolutely disgusting and I’m sure had gone down hill a lot since I first tackled it at the start of this thread fitting the switch suppression cap etc. It was now at the point where a wet goo was oozing and dribbling onto other surfaces.



Annoyingly I didn’t get any good pictures of the ooze, though you can see these wires look wet and that it has dribbled down the heat-shrink of the switch suppression cap I fitted ages ago. It was so disgusting that I just wanted to get it out, and not pick up my phone with sticky green hands.



Here’s a picture of the ‘before’, though again doesn’t show the extent of the goo as it was on the thicker black cable. The motor coils weren’t too bad, it seems localised to the first mm of the sleeve (which I later stripped back and re-tinned).



Here’s a similar view after I’d finished. Not 100% happy with the resistor attachment, I may buy a fresh one and do that bit again. Rest is ok. I just lost the clear sleeving, doesn’t appear to have a function and I notice others have removed it.



Here’s a top view. I killed a figure of eight lead of the type one would use for a ghettoblaster, radio, tape player or whatever. Full UK spec and double sleeved, so an upgrade on where it was.

The 124 is back together and working fine again. This took me most of the day! Quite a fiddly job to figure out exactly what goes where, to get everything exactly the right length, get the routing neat etc.

 

One final view of the bottom as I’m pleased with the overall routing and grounding etc, so may as well show how I did it. Given I used standard coloured mains wire (the original was non polarised bell-wire crap!) I wanted to make sure the live went to the turntable’s switch first and after that to the motor etc. It was pot luck previously, but I think this makes more sense. The chassis and motor have a good solid mains earth. I’m obviously not an electrician but I’d wager this 124 is now far safer than any that left the Thorens factory!