3 June 2017

My Thorens TD-166 turntable serviced by Dr. Thorens

After all, turntables weren't designed to run for more than half a century without service.

By In Gear, Make 7 min read

Four years ago, I bought a vintage turntable. If I’m honest, I did it because I’m a fucking hipster and listening to vinyl is a fucking hipster thing to do. But I really do enjoy it, especially because I stole all of my dad’s old records. Hearing the music he used to play when I was a kid really takes me back. Now, I wanted to have a turntable that would sound better than the cheap, plastic pieces of crap you can buy at any department store (looking at you, Crosley). Buying a vintage turntable is a great solution, as you can get an old premium model for the same price as a new budget model. I ended up buying a vintage Thorens TD-166 model from a local auction site.

Thorens TD166 - Overview

The disadvantage of buying vintage is that nobody expected these machines to still be running half a century later. They were never made to be used for this long without any maintenance, at the very least they want a few new drops of oil. And when cassette tapes and especially CD’s were introduced to the world, many turntables were stores in closets and forgotten for decades. If an owner rediscovers their machine it’s often been neglected for at least thirty years.

According to the serial number my TD-166 was at least forty years old, and when I bought it from the previous owner four years ago he said it had last been used in the ’80s. Any remnants of oil that might still have been inside it from the ’80s would disappeared by my use in the past four years, so neglected maintenance would be an apt description. Luckily, we have Dr. Thorens to come help me out.

Thorens TD166 - Close-up Thorens text

Dr. Thorens, also known as Rob, comes highly recommended on many Dutch audio forums. A passionate expert who spent decades working in the hifi-world, now spending his spare time keeping Thorens turntables alive. It doesn’t matter which model, it doesn’t matter how old, Rob can get your Thorens purring like a kitten again.

Thorens TD166 - Close-up RPM selector

Last November I sent Rob an email with all of the problems I’d been experiencing with my turntable and asked him what it would cost to have it serviced. I received an orderly quote with various service options, but he also mentioned that he wouldn’t have a free slot available until February. Rob’s services are very much in demand. Luckily I wasn’t in a hurry – a few months wouldn’t matter after 30 years of neglect.

Thorens TD166 - Close-up Ortofon Red cartridge

Before I gave the turntable to Rob to do his magic, I did have to do some maintenance of my own – a careless movement of the arm twisted the needle to the point where it could no longer be saved. I replaced it with a fairly budget cartridge, the Ortofon 2M red. Now, again, I have to admit to being a hipster instead of an audiophile – I picked it because it looks damn good on that arm. Probably not the best motivation to select audio equipment on, but c’mon. That does look nice, right?

Thorens TD166 - TP16 mkIV arm

When I brought him my turntable Rob inspected the machine with me, making sure we were in agreement on all repairs and maintenance that would be required. A full clean, lubricate and adjust was definitely necessary, but there could be other issues that required his attention too. Slowly, Rob dismantled the entire machine to identify any parts that were no longer up to snuff. The rubber belt that spins the platter turned out to be so worn and stretched, it was several centimeters longer than a new one. This resulted in the problems the turntable had in switching between 33 and 45 rpm. But that was easily fixed by replacing it with a new belt.

Thorens TD166 - Close-up TP16 mkIV arm gimbal

He identified the tone-arm, a TP16 mkIV, as a non-standard modification to the table. This TP16 comes from a far more premium model than the fairly humble TD-166, which meant that the previous owner must have upgraded it at some point. A great combination according to Rob, who had excellent experiences with all generations of TP16 arms. But the years of neglect meant that there was a lot of play in this arm’s bearings, which meant the arm could wobble sideways when it should really only have vertical movement. The armrest was also mounted badly, which had lead to the incident that destroyed my previous needle. Last, but not least, I had mounted my Ortofon Red element myself and had not done a particularly good job of aligning it. No problem, all of this could be fixed!


Next up were the turntable’s internals. Rob thought that the platter axle required additional dampening, to make sure it would pick up the least amount of unwanted vibrations from the motor. The previous owner had already put in some work to dampen the table, by adding bitumen plating to various spots on the subchassis. Rob was not particularly enthusiastic about the work that had been done here, but the result was deemed ‘acceptable’ and wouldn’t have to be removed or replaced.

The stock audio cables had also been replaced with heavier gauge cables, which Rob approved of, but the power cable and the audio cables were still routed alongside each other. This would invariably lead to interference in the sound, and fixing it required rerouting the cables so they would end up at separate side of the turntable. Internally he also moved the audio and ground cables so they had more slack and would not interfere with the free movement of the floating subchassis.


That floating subchassis was the next problem. Thorens’ claim to fame is their typical turntable design, where the arm and platter are mounted onto a separate subchassis that is suspended from the main turntable body using springs. This way the arm and platter – and in turn, the needle and the vinyl – always move in perfect conjunction with each other when the turntable is playing, ensuring the arm won’t bounce and the audio won’t skip. It’s quite remarkable to see how much vibration a Thorens turntable can handle without skipping, thanks to this feat of engineering.

But for this system to work, the springs that suspend the floating subchassis need to be set up perfectly. And a few decades of weight hanging on all three of those springs had deformed them, requiring additional adjustment for the springs to behave as intended again. The heavy bitumen damping plates were kind of a problem here – that additional weight required additional compensation in the spring setup, to make sure they could handle the heavier subchassis. This spring setup turned out to be the main reason for the long waiting times, as Rob needed to let the springs settle whenever he made an adjustment, making this a rather long and tedious process.

Thorens TD166 - Close-up case

Next up was the aesthetic appearance of the turntable. The entire body got a new coating of black paint to cover all the scratches and dents that had appeared on the surface over the years. The metal top plate was scrubbed clean, and the metal trim on the front was flipped so the mint-looking bottom became the new visible edge. The platter also received a polish to get rid of scratches and discolorations.

Thorens TD166 - Close-up platter

The last detail was an entirely new baseplate. The stock plate is made out of HDF (High Density Fiberboard) which is rather vulnerable to resonance. Replacement baseplates are often made out of particle board, but Rob is not a fan of their resonant characteristics either. For his Thorens turntables he prefers Trespa, a type of HPL (High Pressure Laminate), a more modern board material made out of a paper base pressed into shape. This sounds lightweight, but a thin Trespa baseplate is as stable as one made out of 2 centimeter thick particle board. To further ensure isolation the baseplate is mounted on three feet made out of Trespa.

Thorens TD166 - Close-up record

Quite a shopping list! But two weeks later Rob emailed me that my Thorens was done and in perfect working order. What a difference two weeks can make. Everything feels smooth and good again, operating as intended. The TD-166 is back in my living room, spinning the records that my dad used to play when he was younger.

(Original post in Dutch)

What do you think?