A 20 year, or 3,500 mile service of my Thorens 124/II turntable

[Barry]

A 20 year, or 3,500 mile service of my Thorens 124/II turntable


As part of a ‘spring clean’ of my system, I have just given my forty-year Thorens 124/II turntable a service. Nothing too radical: the last time I gave it a service was about twenty years ago when I replaced the drive belt and rubber suspension ‘mushrooms’.

So too this time: I had noticed the belt had become ‘tired’, slightly stretched and would sometimes slip initially on switch on. This was only the third time I have replaced the drive belt. I estimate the replaced belt had travelled 3,500 miles in twenty years.

Before I replaced the belt I took the opportunity to give the exterior of the deck a good clean and clean out the old oil from the platter bearing well, replacing it with fresh Thorens approved oil. At the same time the oil in the stepped pulley well, was renewed, as was that of the idler wheel bearing. The idler wheel has never been changed it, is still the original. I once tried a new idler wheel but for some reason I found the noise level was increased, so the original was returned.

The new Thorens drive belt is a tighter fit on the two pulleys. Comparing the old with the new, it was clear that the old belt had indeed stretched slightly.

At the same time I fitted a separate earth wire to the turntable chassis. Before the turntable metalwork was earthed using the earth wire of the pickup arm. Now both the earth wires are taken back to the ground terminal on the phonostage; that is, the ‘daisy chain’ grounding is now replaced by ‘star earthing’. I now have the option of using either arrangement (but not both, as that would create an earth loop).

Finally, I replaced the four rubber suspension ‘mushrooms’. After twenty years, they had started to collapse and harden.

So has the sound quality improved? Well mechanically it still takes a few seconds to settle down to the correct speed as adjudged by the stroboscope, and just over a minute for the platter to come to a complete standstill after switching off. These are not especially impressive results, being about the same as those before the service. However I do feel the ‘timing’ has improved, PRaT and all that, with a reduced noise floor.

I was going to take a few photos of the work, but I don’t think they would have been especially informative.

[Ammonite Audio]

I love my TD124 and find that routine maintenance is required to keep the motor and stepped pulley clean of rubber belt gunge. It gets noisy when the gunge builds up, but a few minutes with some cotton buds and isopropyl alcohol cleans up the pulleys perfectly. A light dusting of talcum powder on the belt helps too.

One thing I've learnt with the TD124 is that, if you have a nice quiet idler wheel, do not ever part with it or be tempted to try another because most are noisy. I have tried so many idlers and finally settled on one that is as quiet as is reasonably possible. Much of the idler noise is actually generated by the stepped pulley and I found that polishing that pulley with very fine abrasive paper and Duraglit helped enormously. I have also learnt (by experience) to never use any form of solvent on the idler wheel, since this can immediately harden the rubber and it's then noisy and useless. I have found that a dry block of JML Magic Eraser (or similar) can very lightly hone the edge of the idler wheel to reduce noise further.

[Barry]

Good points Hugo.

I did clean both pulleys with IPA and a kitchen towel. Agree about the idler wheel - never let it anywhere near solvent, and handle it with lint-free cotton gloves.

Realised I have underestimated the distance travelled - I forgot the motor is four pole induction design. The total distance travelled by the belt is more like 80,000 miles.

[Marco]

I was going to take a few photos of the work, but I don’t think they would have been especially informative.

Oh, go on, Bazza - we don't often get a chance to see your TD124, so............



Marco.

[Barry]

Oh, go on, Bazza - we don't often get a chance to see your TD124, so............



Marco.

They (I have three) look just like any other TD124/II. But if Tabatha is "nice to me", I'll have a go.

[Marco]

Well, she's offering to 'clean' some of your records in her own inimitable style, if you show pictures of the Thorens you've just serviced...

Oh, and she also mentioned something about you standing beside it, sporting nothing but a pink cravat and a cheeky wee grin!

Marco.

[Barry]

Now don't be daft! A cravat would just look silly, whereas a pink bow tie would look much better.