Top Ten List; Number 2 (belatedly). The Thorens TD 124

by Nick Seiflow

Humans. Over 6000 languages, but I’ll wager that only German has the *mot juste* to describe the-performance-of-an-action-with-brute-force-whilst-using-the-utmost-delicacy.

Actually it’s not necessary. The Thorens TD 124 is better than any word.

Looking down on a rebuilt 124, complete with original armboard and Formula IV Unipivot tonearm. Forty Pounds Sterling (without arm) in the early '60s......

Looking down on a rebuilt TD 124, complete with original armboard and Formula IV Unipivot tonearm. Forty Pounds Sterling (without arm) in the early ’60s……

A cross between a Breitling watch and a combine harvester, the TD 124 is another of the Great Tables. To dissect this spinner is to witness problem-solving Swiss-Style, and can only engender respect in the viewer (and listener…)

TD 124 Mk 1, Serial#38259.  In the centre of the lovely chunky speed selector we see the star-shaped fine speed control wheel. Note the range of voltages and frequencies that can be achieved!

TD 124 Mk 1, Serial#38259. In the centre of the lovely chunky speed selector we see the star-shaped fine speed control wheel. Note the range of voltages and frequencies that can be achieved!

Underneath its beautifully rounded cast frame there is much to describe. What follows is necessarily brief.

It’s an idler drive. But not any idler drive. Unlike the legions of cheaper idlers this one was built to be the best. Almost sixty years later many of us still think it’s just that.

A top-down approach reveals that there are not one, but two platters. The topmost is a relatively lightweight affair, aluminum with an attached rubber mat and captive 45RPM large hole adapter sprung in place. Underneath this is a simply massive cast platter sporting a superbly machined and polished spindle and bearing (original literature suggests that the machining tolerance for the spindle was 1/1000mm). Why two platters? It’s to do with the large motor. When starting the TD 124 from cold the motor will run a percent or so slow for the first couple of minutes and then will run perfectly at speed (possibly for ever given the size of the motor). To avoid speed anomalies (and to achieve a sort of instant cueing for radio stations) the user would keep his or her TD 124 running continuously, not switching it on or off, and raise or lower the top platter to start or stop a record whilst keeping the lower platter spinning at a constant speed. Swiss engineering….

And a little more than half of the top aluminum platter....

And a little more than half of the top aluminum platter….

Closer view of the ribbed top platter mat, showing the spring-loaded 45RPM large hole adapter, and at the right hand edge the clutch to raise the top platter.

Closer view of the ribbed top platter mat, showing the spring-loaded 45RPM large hole adapter, and at the right hand edge the clutch to raise the top platter.

Half a beautifully machined and painted steel lower platter. The rows of peripheral dots, lighted by the built-in strobe, are viewable through the small window at the front centre of the turntable. Different spacing for different voltage line frequencies....

Half a beautifully machined and painted steel lower platter. The rows of peripheral dots, lighted by the built-in strobe, are viewable through the small window at the front centre of the turntable. Different spacing for different voltage line frequencies…

It is an idler drive. Detractors, and there are some, don’t approve of the idea of large motors not being isolated from platters. Fair point (kinda), and it is partially the job of the second platter to provide isolation. But this wasn’t enough in the view of the engineers at Sainte-Croix. Unlike the wonderful Garrards (301 and 401) and the big Lencos, all beautifully built idlers, the 124 uses a belt between the motor and the idler mechanism to provide even further isolation. It all adds up to a really rather marvelous turntable. Well of course it’s still revered! How could it not be.

Underneath the platter(s), showing the spindle well (sintered bronze) at bottom centre. From upper left to right: reversible motor pulley (noting two very small balance holes), belt, stepped idler pulley and brand-new idler wheel. Note the large magnet next to the idler pulley; using the principle of eddy-current braking, fine control of speed is achieved.

Underneath the platter(s), showing the spindle well (sintered bronze) at bottom centre. From upper left to right: reversible motor pulley (noting two very small balance holes), belt, stepped idler pulley and brand-new idler wheel. Note the large magnet next to the idler pulley; using the principle of eddy-current braking, fine control of speed is achieved.

A close view of pulleys and eddy-current braking magnet.

A close view of pulleys and eddy-current braking magnet.

Underneath The Beast. Simple, elegant, and extremely strong. Built to last a century?

Underneath The Beast. Simple, elegant, and extremely strong. Built to last a century?

An examination of the motor pulley reveals tiny drilled holes for balance – and it’s reversible for 50Hz or 60Hz use (a lovely touch): when spinning it’s actually hard to see that it’s moving, such is the accuracy of the machining. The same could be said of the idler wheel itself. Big motor, massive platter, lovely clunky switchgear and nth degree engineering come together to produce the Thorens TD124.

An easily replaced arm board, attached in place with three heavily chromed screws, and the joy is complete.

An exceedingly rare unipivot arm, complete with dedicated Thorens armboard. The signal is conducted through the arm pillar using four small wells of mercury: excellent and highly innovative engineering, but we don't think it will be produced again....Ah, the '60s.....

An exceedingly rare unipivot arm, complete with dedicated Thorens armboard. The signal is conducted through the arm pillar using four small wells of mercury: excellent and highly innovative engineering, but we don’t think it will be produced again….Ah, the ’60s…..

Of course the original plinth does not date quite so well, being somewhat perfunctory and thin, but there is a veritable army of plinth makers (plinthiers?) all with their own ideas of how best to support and display the TD 124; the one illustrated is a nice stepped ply wood affair, all the way from sunny Moldova, and does its job quite beautifully.

Front view showing the multiple layers of birch ply for the plinth.

Front view showing the multiple layers of birch ply for the plinth.

A typical original plinth. Not much in the way of real isolation and support; best improved.....

A typical original plinth. Not much in the way of real isolation and support; best improved…..

A typical replacement plinth; solid, effective, and so much better than the original flimsy box. The stepped design is designed to safely increase overall density whilst allowing for sufficient air circulation around the motor.

A typical replacement plinth; solid, effective, and so much better than the original flimsy box. The stepped design is designed to safely increase overall density whilst allowing for sufficient air circulation around the motor.

So, a brief peep at one of the Legends. Much, much more to write but in the interests of brevity I’ll cut it short for now. Almost 60 years old, and so well put together I suspect that it will last another 60 years. If only I’d been built by the Swiss….

N.B. Keeping the TD 124 Alive For Ever.

Working on the TD 124 and upgrading it is relatively easy. Aside from rebuilding the motor (which requires some precise work) refurbishing the turntable is not terribly difficult. Having rebuilt some basket cases and returned them to their former glory I can say that this is one of the most rewarding undertakings in turntable-world. Using one at home (in fact I’m listening to one as I scribble) makes me once again ask how much vinyl playback has improved over the last half-century. My Quad 57 speakers date from about the same time, and it’s difficult to imagine better sound. Methinks we knew a thing or two in 1960….

3 thoughts on “Top Ten List; Number 2 (belatedly). The Thorens TD 124

  1. Thanks for this interesting post and great clear photos. One question you might be able to answer: I am working on the TD124/II which I bought in college in 1973 to bring it back to top condition again after about 15 years in storage.

    I cleaned wherever I could reach and lubricated the motor shaft (unable so far to get at the two tiny screws to remove the 50-60 cycle pulley). Removed stepped pulley and idler wheel (which look in good shape and cleaned both with alcohol. Replaced the belt today with correct new one. Motor spins fine and, with new belt, so does the stepped pulley and (apparently) the idler wheel (when platters removed).

    However, when I replace the platter and switch it on again (e.g. to 78 rpm), the motor and drive doesn’t have the strength to turn the platter.

    To me, whatever spring or tensioner holds the idler pulley against the stepped wheel doesn’t seem to have the strength needed to hold close enough contact between the two, thus power is being lost in transmission.

    Any suggestions? if there is such a tensioner spring, can it be adjusted or replaced? Or am I barking up the wrong tree entirely?

    Appreciate any guidance… I’d ship it to you but am on the other side of the world.

    Cheers,

    JL

    • Hello Joe,

      There is a sprung assembly which swings the idler wheel into contact with the platter; this is clearly seen when the deck is turned upside down. It’s more than likely that the grease on the main shaft has thickened and hardened, and this is probably what is causing the problem. Disassembly is quite logical. although it might appear intimidating at first – wok slowly and all will be well! – cleaning all the old grease off as you go, and re-greasing where necessary. When you have finished and re-assembled the assembly I have no doubt that all will be well. The beauty of the 124 is that it is so simply made, and robust, that it is a joy to work with; this kind of ‘repair’ will give you all the confidence you need to keep this wonderful deck running for ever!

      Best regards from the Other Side,

      Nick

  2. Hi,
    Great article. I’m currently restoring a MKII and enjoying it immensely. I have just finished the motor overhaul and installed a set of aftermarket machined sintered bronze bearings as original cast phosphor bronze are not available. It’s running for a week to break in, with periodic stops to check the coast-down time and put a drop of oil on the bearings as a precaution. I had to polish the rotor spindles as they were scored when the old bushes dried out, but this inevitably removes some material so the tight manufacturing tolerances are no longer there. I’m also a little worried that the machining of the internal bore could have reduced the number and size of pores for the oiling, but we’ll have to see how it performs. To be honest, at the running speed of any part of the drive train, 1/1000mm is overkill (and Swiss pride?). Standard replacement bushings have a clearance of 0.04mm, so a smidge either way won’t make any difference. You can also infuse slightly different viscosity of oil if necessary, light for tight clearances and increasingly heavy as the clearance increases. I had some problems finding oil as the bearing manufacturers used additive free SAE 30 oil. I eventually found what I was after as a classic motor oil for vintage engines, totally additive free SAE 30, but there are a lot of different opinions. As the metal is porous and the oil migrates in and out of the pores, additive free is best in my opinion, but I saw one well known Hifi magazine recommending Redline 5W40 motor oil, which has additives for modern engines.
    Anyhow, I thoroughly enjoyed your article. Please feel free to e-mail me any additional TD124 information, specifications, etc….

    Regards,
    Robbie.

Leave a Reply

Your email address will not be published. Required fields are marked *