This charity shop find is of unknown provenence. The TD160 mkII was current in the late 1970’s. This one looks like it’s been in storage for a while .
I’m assuming the worst and giving it a full service. There is a long list of things which need attention.
I’ll be covering the following:
- Mains wiring
- Signal wiring
- Drive system
- Tonearm and suspension.
- Cartridge
- Setup and testing
Mains Wiring
The turntable had recently passed a “Portable Appliance Test” (PAT). The label is there on the cable. All good then.
Well, No. It may have been tested, but all was not well. The cable was not secured in the strain relief clamp. Worse than that, it was fitted with a 13 Amp fuse when 3 Amp is appropriate. That’s two rookie mistakes. Both problems quickly and easily fixed.
Signal Wiring
The phono plugs were in a shocking state. Tarnished and noisy.
I cut off the old plugs and replaced with gold plated versions. I now expected the turntable to give good sound. Only left channel worked. Investigation with a multimeter tracked the problem down to the cartridge. Left channel coil measured at about 800 ohms. Right channel open circuit.
I connected the right channel wires to the left channel pins on the faulty cartridge to confirm that the wiring in the tonearm was ok. The cartridge fault is not repairable so a new cartridge was ordered.
Drive System.
The TD 160 is a belt drive table. Belts deteriorate over time. This belt was stretched and inflexible. Nonetheless, it was able to slowly bring the platter up to correct speed. This encouraging result confirms that the motor is good and the platter turns well.
Before fitting a new belt the outer edge of the sub-platter was cleaned up with fine wire wool. This removed the oxidation build up and provided a smooth surface for the belt to grip.
I also cleaned the main bearing, which was found to be in excellent condition. New oil was added and the bearing re assembled. The sub platter engaged with a satisfying bounce as the trapped air was expelled past the fresh lubricant.
The platter turned accurately at both 33.33 rpm and 45 rpm, as measured with a strobe disc.
Now I have a new problem. On start up the platter and arm lurch violently for a couple of seconds. It hadn’t done that with the old belt! The problem is caused by accelerating the heavy platter too quickly. The motor pulley incorporates a slipping clutch mechanism to prevent this from happening. Unfortunately my clutch wasn’t slipping. It had siezed up. A little gentle persuasion with a pair of rubber jawed pliers released it. Starting is now smooth. You can hear the clutch slip for a second or two as the platter accelerates to running speed.
Tonearm and Suspension
The TD160 can accomodate different tonearms, should the Thorens offerings not float your boat. This table is fitted with an ADC ALT-1.
With the bottom of the plinth removed I noticed the remains of an elastic band on the tonearm mount. Initially I had assumed that this was just a bit of old packaging. I now believe it was there to hold the signal cable clear of contact with the plinth base. The correct solution to this is to modify or replace the plinth. Some time later that will no doubt happen. For now a cable tie where the elastic band was will have to be sufficient.
Prior to fitting the new cartridge there was not much I could do in terms of tonearm adjustment. However, I did notice that the cue arm lifted the stylus to a great height above the record. About 15mm. Not much use for accurate queuing. I managed to lower this to about 5mm by losening the set screw securing the damping cylinder and carefully lowering it. A very fiddly job that took several itterations to get right.
The turntable and arm are attatched to a seperate sub platter which is suspended from the rest of the unit by three springs. I was able to adjust the nuts on the springs to get the platter sitting level at the correct height.
Cartridge
The broken cartridge needs replacing. I’m a big fan of the Audio Technica VM95 series cartridges. I have the Microline version on my Dual 505. However, the ALT-1 Tonearm is classed as having a low effective mass. This means that it is best partnered with a high compliance cartridge. So I’ve read. That suggests that the VM95 may not be a great match. It’s always interesting to try something different. The Ortofon 2M Blue looks to be a better match for compliance and enjoys glowing reviews. The Thorens is a posh enough turntable to justify a premium cartridge. 2M Blue it is then.
It was not a straightforward installation. First problem was that the wires were a lose fit on the pins of the cartridge. This was solved by gently and very nervously squeezing the connectors with pliers to close them up a bit. Inserting a cocktail stick first helps to prevent accidentally squashing the connector up too much.
The second problem was lack of clearance for the connectors where they enter the headshell. The Ortofon 2M series cartridges have a large wide body which was right up against the wires. I had to carefully bend out the connectors, having first removed them from the headshell.
Setup and Testing
Overhang was checked with a protractor. I couldn’t get this quite right. I suspect ther may be an issue with the arm installation. The arm pivot seem to be 5mm or so too close to the platter spindle. It’s good enough for now though. Tracking force set to the recommended 1.8 g using an electronic gauge. Anti skate was set using a test record with a un grooved band. All now works very well.
At the time of writing I have been hapily using it for about a week. A combination of background listening while working and a few Critical listening sessions with headphones.
This has confirmed that it is indeed a fine turntable.