-edible zone-

-- Takeaways from Swiss Precision, a Review.

Book: Swiss Precision: The Story of the Thorens TD 124 and Other Classic Turntables
by: Joachim Bung
2nd Edition - English Language
Publish date: 2008
Review date: October 22, 2020
Reviewer: Steve Clarke


  idiot holds a book

above photo:  reviewer holding the book

Swiss Precision 2nd ed. Is a physically large history book with 289 high quality heavy glossy pages and 571 photos. It is a comprehensive history of the TD124. It also tells history of competitor turntables from the time period. It details and compares tonearms of the period. Cartridges. The Hi-Fi industry around the world and in Germany during the early days of stereo. Then it looks at the 21st century popularity of the model.

Up front we have text and imagery to tell the story of the Thorens TD124 record player and of the company and people who produced it. We get the development and production history of it alongside its sibling products including the TD184, TD134, TD135, TD121, TD110, TDK101, the TD224 “robot arm” changer, TD124/II and TD135/II. All of their platters are propelled by the same essential tech, an AC induction motor driving a Belt-idler transmission.

From the half-automatic phone-dial TD184 and the simpler TD134 (page 38) semi-auto models to the least expensive TDK101 kit turntable (page 51), every model is included. And there’s a lot of coverage for that eye-catching Thorens TD224 robot-arm record changer. (page 107)

The photo on page 13 shows a TD124 being hand assembled by an individual sitting at a bench holding a TD124 chassis with one arm while attaching parts to it with the other hand. There is a double row array of bins in front of him. The bins are full of parts. It's how he works. It’s one of several production photos. The main takeaway here is that every TD124 was hand built. But I kept thinking how cool it would be to have all those parts!

There are many interesting stories in this book. One is about how a phone number offered to the author by Olga Kelch, (p77) leads to Bernhard Streit in Lake Geneva. Bernhard Streit puts the author in touch with Robert Thorens in Ste. Croix. There’s a formal meeting between the author and Thorens. Much inside info from this period is made available to the author courtesy of the engineer that knew the product first hand from its beginning. Story on pages 77 through 83.

Several interesting photos: The photo on page 14 looks vintage. It is an overhead shot of the old Thorens Works in Sainte-Croix, Switzerland. I can’t tell from when the photo is taken but the surrounding streets are narrow. No vehicles seen. In the left part of the photo we see the very large mansion where the company founder Hermann Thorens lived. It is adjacent to the close grouping of a dozen buildings that would have been their manufacturing facilities. You’d have to walk several yards to get to work…..if you were the boss. Actually it looks like the boss had to hike all around that place and the exercise probably kept him in pretty good shape. We know that Thorens started the business by producing music-boxes back in 1883.

Music boxes and wind-up spring motors in the beginning years. Just looking at the photo I get the idea that the music box business was lucrative.

Imagine being there for a day circa 1913. Thirty years after registering the business in 1883. Just three years after the mansion was built in 1910. It’s one year before the first world war. You’d need a stable to rest and feed your horse. I’d guess the home and factory had electricity by then but who knows. Perhaps Thorens owned a motor car, or maybe he didn’t…... at least not yet. The house is large and looks like it needed a staff to run it. Perhaps they had a butler and a maid or two.

Louis Thevenaz, head of development at Thorens Sainte-Croix is credited with the TD124 design concept and its reality. See Page 14. There’s a photo of him there. The photo on page 15 is of a prototype TD124 chassis with an id tag showing the serial number 1001. Externally it’s not quite yet in the familiar form. With the flywheel off and looking into the chassis we see similarities and differences between it and the production unit we know. The author tells a story about this particular player, how it was built and where it went. On page 16 there are some photos of another prototype with an id tag showing serial number 1003. This one looks from the outside very much like the first early production version of the TD124. Instead of cast iron, it has a brass flywheel. That flywheel, if it has the same dimensions should be heavier in brass. (Density of cast iron: 6.85 – 7.75g/cc, Density brass: 8.5g/cc) Anyway with the flywheel removed we see just one difference between it and production units. There is an id tag riveted in place where on production versions we see a large circular cutout. Production units carry their serial numbers on the facia at the speed switch and are readily seen at a glance.

Also on page 15 is a photo at page bottom showing the adjunct between arm board platform and the chassis. It’s a square shoulder. We know that some time later in the first run that this area was revised to incorporate a large bevel that would somewhat strengthen the joining between the arm board mount surface and the chassis shoulder.

Here is where I can volunteer some useful (I hope) commentary. I’ve seen three early TD124 chassis that had the square shoulder. One had serial number 2078. Another was 2128 and the third was 2729. In addition to the beveled corner adjunct there are other changes made in this undocumented chassis revision. These revisions are to be found in the arm board area involving some angular gussets. Gussets both in the vertical from underneath and horizontal. Obviously this revision was done to strengthen this area of the chassis. I know from my own experiences that it is not uncommon to find these ~60 year old early samples of the first version to be slightly bent around the arm board area. On the later revised chassis that I have seen none were bent. I should note that it has been possible to straighten the bends into a flat and usable condition on the three samples noted above.

Page 114 shows company bulletin #212 circa 1959 which reports measured performance data of the TD124, TD134 and TD184. This report refers to the NARTB standard 1.11 for deviations in pitch which must be less than 0.2%. I notice that for wow the TD124 reports a reading of 0.10% while the TD134/184 reports 0.20% wow. (wow!) Flutter on the TD124 reports at 0.07% while on the TD134/184 reports at 0.10%. The bulletin goes on to report unweighted rumble figures per NARTB std. 1.12. The TD124 reports unweighted rumble at -38dB while the TD134/184 report unweighted rumble at -36dB. There’s more to the report but these particular measures took my attention.

I also note that these are new units being tested. And I presume the difference in performance between the TD184-34 and the TD124 was in the chassis material. Pressed steel for the less expensive units and die-cast aluminum for the TD124. Clearly the more solid cast chassis plays quieter and with greater pitch accuracy. They probably saw it as worth the expense.

On page 17 there are two photos of the EMT R80 broadcast turntable. One shows the whole thing fitted with the later EMT 997 arm. The second photo is a close-up detail of the tonearm position indicator. The R80 was the predecessor to the EMT 927. Photos of this model are rare, as are the turntables themselves. It appears to be a two speed model with 78 and 33-1/3rd. This reference to the highly regarded broadcast turntable brand EMT is made to illustrate the ambitions that Thorens had for their TD124. They wanted a model that could be taken seriously enough for professional broadcast use, but affordable enough for use in the home. Thorens wanted to have the instant start cueing ability as did the EMT broadcast players. Turn the page over (to p18) to find a photo of a pair of TD124 players being used in a Spanish radio station. The sign on the shelf above says “Radio RIOJA”.

That motor: (the E50)

page 21 direct quote: "The flywheel was driven by a 10-watt 4 pole induction motor. Contrary to more powerful motors, this one tended to give off much less vibration. Its rotor was dynamically balanced to tolerances that were more normal in laboratory instruments. The motor was very smoothly attached to the base plate so that the vibrations that were still possible could be damped even further. Additionally, the weaker motor had the advantage of lower eddy current."

page 30 direct quote: "A gently suspended four-pole induction motor running at 1,350 rpm transmitted its energy to a step pulley running at a speed of 700 rpm via a short flat belt. The reversible motor pulley secured by two locking screws had two different diameters for use at 50 and 60 hz cycles." note: the above 1350 rpm figure is for 50 hz operation.

"The 70-millimeter step pulley was fitted with a step for each of the four selectable record speeds, 16 2/3, 33 1/3, 45, 78 rpm that were twice as big as that of other step drives." "Depending on the speed set, the precise idler wheel ran at only 100 to 200 rpm".

My comment:

A bit more info on this motor would have been welcome. Otherwise, one individual* measured an operating motor at "best speed" with a laser tachometer at 1450 rpm on 50 hz.

*Simone Luchetti of AudioSilente who supplies spare parts for Thorens TD124 as well as updated motor coils that duplicate the coils used in the mkII motors.

Page 65 describes the non-magnetic flywheel/platter. (part number CB 788) He tells us that Inca, the same foundry that produced the TD124 aluminum cast chassis, also cast this non-magnetic flywheel. It was a zinc casting. The finished weight was 3kg*. Available since 1963. This platter was standard issue on the TD135 and TD135/II models. On the TD124 and TD124/II an adapter plate was required in order to fit this flywheel to the TD124 bearing. The author tells us this non-magnetic platter was available by ‘special order only’ for the TD124 and had been since 1963. In other words: On the TD124 It was always optional, never standard issue.

With the above paragraph in mind I’ve noticed that it is common in the United States to find TD124/II players fitted with this 3kg zinc flywheel. In fact it is less common to find a TD124/II with the iron flywheel. This makes me wonder how it came to be. In that time Elpa Industries was the importer for Thorens products coming into the United States. I could take a guess that Elpa ordered them that way. But that’s just a wild guess. Plausible perhaps.

*footnote: the iron flywheel weighs 4.5kg.

On page 65 the author tells us that the go-ahead had been given by Thorens for use of the Ortofon SPU and SPU/T cartridges over the cast iron flywheel of the TD124. However we learn of two cartridges that Thorens did not approve for use above the iron flywheel, those were the Decca FFSS and the Neumann DST.

The TD124/II production history…..1966 – 1968 page 57.

Code name: TD124 Super. At the Paillard development lab in Yverdon, there was a motor suspension revision made. They doubled the number of grommets holding the motor to the chassis to reduce rumble measurements. Changed the exterior finish color from beige to gray. Revised the external shape of the speed-switch knob and its integrated fine-pitch adjuster. The ribbed rubber pattern on the platter mat was altered. The BTD 12s tonearm was revised into the TP14 at this time.

There is no mention in this book of any revisions having been made to the E50 motor coils.

Production quantities for the TD124:

TD124 total produced: ~60,000 (1957-1965) (ref p57)

TD124/II total produced: ~35,000 (1966–1968) (ref p68)

Production life all models 1957 - 1968:

TD124: 1957-1965
TD184: 1959-1963
TD134: 1959-1963
TD135: 1961-1965
TD224: 1962-1966
TD121: 1962
TD111: 1962
TDK 101: 1962
TD124/II: 1965 – 1968
TD135/II: 1965 – 1966

On page 74 we learn that by 1966 production of the TD224 and TD135/II ceased. Production of the TD124/II component parts came to an end due to high inventory quantities, while the TD124/II itself continued to be assembled until the end of 1967. We also learn that in the UK TD124/II models held in inventory continued to be sold as late as 1970.

On page 90 there is a photo of a scene within a broadcast booth. It’s a 20-something blond female at the microphone. She’s smiling and has her left hand on an EMT 928* broadcast turntable while it tracks the record. Just next to the 928 is another EMT turntable, a 930st. The title for the text below reads “Introduction of the Thorens TD125”. And then the story of how the TD125 developed in Lahr begins.

Footnote*: The EMT 928 was EMT’s version of the TD125 but designed and built for use in the broadcast booth.

There is coverage on the many different tonearms from around the world that were in common use on the TD124. This part of the book is interesting because the years covered describe the early days of stereo reproduction. From all this we get a fair impression of what an inventive and transformative era it was for tonearms and cartridges.

Pages 173 through 188 cover Ortofon tonearms and SPU cartridges.

Included in this 15 page spread we see several items in its product history. A record cutting lathe. A moving coil mono cutting head. A Delphon turntable with an RK 309 tonearm. RMA 309. SMG 212, RMG 309. Those tiny pick-up transformers that fit into the SPU/T and SPU/GT head shells. Elliptical stylus on SPU. Distortion and Noise in 1963. G-type headshells. Tech data sheet RMG 309. RS 212. First one shown with anti-skate. Hi-Jack cueing device in 3 versions. The modern AS 212s and AS 309s tonearms. I list a fraction of the book content for these pages.

Pages 189 through 197 cover the original SME 3009 and 3012 Series 1 tonearms as well as the Series 2 arms. The list of other tonearms covered include Grado, Empire, ESL, Fairchild, GE, Rek-O-Kut, Pritchard, Shure, Micro MA-77 and MA-88 models just to name a few.

The author goes into plenty of detail on tonearms coming from Shure during this early stereo period. The M212, M216, M222 and M226 Stereo-Dynetic integrated tonearm and cartridge (p198 – 201) are the double pivot type where the horizontal pivot is concentric around the base mount but the vertical pivot is out closer to the stylus business. To cue the stylus on and off the record there is a knob further inward along the tapered beam I want to call an arm tube. It’s a strange angular shaped arm that is somehow intriguing to look at. I can imagine that when these were new they must have been thought of as very modern. They certainly were radically different from any other arm of the time. Being from that period, 1958 to 1960, none have anti-skate and they are limited to one cartridge, the M21, but with replaceable stylii. It could track as low as 1-1/2g.

A quick search on ebay turned up examples of these integrated arms that can still be found…... and they don’t seem to break the bank. I wonder if those jeweled pivot brgs out near the head shell can get loose. There is a photo of an M216 in use in a broadcast booth on page 201.

There’s coverage of the many cartridges in popular use during this early stereo era including the Ortofon SPU moving coil types, the GE Variable Reluctance cartridges. Cartridges from Shure like the M3D Stereo Dynetic for use on those Shure M232and M236 Professional series arms. (p204 - 205) We see info on the Shure M33 and M77 cartridges. Then the M44 and M55 cartridges which appear more modern in outer shape.

The GE VRII cartridge is seen on page 40 and 41 being used in combination with the BL-104 Thorens tonearm.

The tonearms designed and produced by Thorens are covered. These include the BL-104 arm used previously on the CBA-83 turntable, the BTD12s which is revised later into the TP14 and then revised yet again into the TP25. One of the things I noticed on this development starting with the BTD12s is that it isn’t until the TP14 that we see an anti-skate mechanism employed. The TP14 is introduced with the TD124/II in 1966. The TP13 tonearm that was used on the TD150 turntable is described on page 69. It doesn’t have anti-skate.

On page 72 the author tells us that the EMT 929 tonearm was inspired by the TP25 and not the BTD-12s as has been popularly thought. It seems plausible to me since Thorens was owned by EMT during the development of the TD125 and its TP25 tonearm from 1966 going forward. The two companies were neighbors in Lahr. EMT could have had hands-on experience with the Thorens arm and no doubt they were able to interface with its designers at Thorens.

On Page 69 there is another story involving the head of development at Thorens meeting with Edgar Villchur of Acoustic Research in Hawaii circa 1963. Not long after, Thorens in Sainte-Croix developed the TD150 player. Personally, I have a fondness for this unit. And by association I must also appreciate the original AR-XA from which it developed.

There is an interesting Thorens company history reported in this book. While this history is limited in scope to the time of the TD124 and going forward it reveals a company that had once been organized to make music boxes, and how it had evolved several times over the years but still retained its traditional philosophy. It tells of a facility complex that grew organically around the process of individual hand assembly. To borrow the author’s phrase, it was “One big Workshop”. Competitors, however were producing their products using more modern assembly-line methods at a much lower cost of production while retaining high quality of product. Dual is sited as an example.

By 1962 the Thorens operation is sold to Paillard-Bolex also in Sainte-Croix. But this doesn’t last. Paillard-Bolex sells the Thorens turntable business to Wilhelm Franz of EMT in 1966. Then the Thorens turntable business moves into the EMT neighborhood in Lahr, Germany. And there were some interesting turntables designed and built there. But by 1984 we have the introduction to the world of the compact disc player. With the CD we had digitally reproduced music and everything changed over-night. Thorens restructured to lower their costs, then In full sight of what must have looked like complete obsolescence, they continued developing new turntable models. This goes on up until 1991 when the Thorens-Franz AG distribution center in Wettingen closes down. (the author uses the word “bankruptcy” page 96). And that is where the Thorens history stops in this book. In reality it wasn’t over for Thorens in Lahr that year, they’re still selling turntables today, but that is a topic for a different article.

While the company that produced the TD124 can’t make them any more, there is a continued demand for any and all specimens. They’re easy to refit and everything on them can receive maintenance. In that spirit we find on page253 a new chapter titled “The Rediscovery of the Thorens TD124” That chapter brings us from the 80’s into the 21st century where the ‘rediscovery’ continues and the sale of vinyl records continues, plus we have the generations that follow us getting interested in the pleasures of analog audio.

end.

Post Script: There is much more content to be covered if I were to summarize the entire book. Far more content. But these are my pick of the larger takeaways regarding the history of the TD124. If you want to buy a copy of this book, or perhaps the new expanded 3rd edition you can find more information at the author's website. Link here: https://www.joachim-bung.de/en/