5/20/2010 revisions made 5/7/2014
Notes on the TD124
Some general observations:
One good indicator of drive-train health that makes itself known is by how well the turntable reproduces musical detail. Sharp, articulate delivery indicates good overall health. Soft blurry reproduction of musical detail indicates a turntable in need of maintenance.
Definition - Rumble: A low frequency noise, generated by the various moving parts of the turntable drive-train system, and making itself evident through the speakers of your audio system. With the mk1 motor mounting configuration, there can be a slight audible evidence of rumble heard through the speakers. Typically this can be heard in the un-modulated grooves of the record. The lead in groove. The dead wax. In a healthy TD124 you'll need to listen carefully for it. However, the worse its mechanical condition, the more evident the rumble. That said, and if you have a mk1 motor unit, see comments lower down on the mkII motor mount conversion kit. Installation of it can potentially remove audible evidence of rumble completely.
Often times deteriorating drive train-health doesn't become known until the
owner hears another turntable and makes a comparison between his Td124 and the
other table. Another useful comparison is made between two different TD124
motor units. One, presumably healthier than the other. That can be
The stepped pulley can be a source of noise depending on which version you have and whether it is, or is not, in good condition. The earliest version (the one in my three turntables) tends to operate quietest. Just make sure it has lube in its bushings and at the top where its ball bearing thrust is. All pulley surfaces need to be clean of any rubber residue from the drive belt and also from the driven idler tire. An accumulation of rubber residue on these surfaces not only affect speed, speed consistency (wow) but also noise levels. Use alcohol with Q-tip to maintain cleanliness of these surfaces.
About Lubrication: The TD124 service manual suggests using a straight 20 wt turbine oil in the main bearing, the motor bushings, the stepped pulley and idler wheel bushings. The exact formula recommended is no longer available, but a replacement with the same essential characteristics is. Texaco R&O 46. It is not available at auto parts stores. Instead, you can get it by the 5 gallon drum at your local oil distributor. Sigh.... But do not despair.....There is a practical replacement. Straight 20 wt Electric Motor lube from the 3-in-One company. Don't mistake it for 3-in-One oil. You want Electric Motor lube in 20 wt. Your local hardware store should carry it. It is ok to use this in place of "Thorens Oil".
When it comes to the motor, a whole new level of improved sound awaits your maintenance effort. Disassemble, clean, replace motor rotor bushings with new ones*, replace motor brg thrust pad, replace the wicker felts, (or at least rinse out the old ones) give it some lube(20 wt), install a Mk II motor mount grommet kit, assemble, adjust bushing-to-shaft alignments for quietest operation, let it run in for a week, then disassemble, clean all bearing surfaces, re-lube, reassemble, readjust bushing-shaft alignments once more. Now you can listen critically.
* it may not be necessary to replace the rotor bushings in the E50.
Depending on the condition they are found to be in. Evidence of wear or
the lack thereof, etc. The old lube can be baked out of the old porous
bronze bushings. Rinsed in lacquer thinner. The cleaned bushings can be
soaked in hot 20wt oil and then put back to use.
The E50 and its aging coils. One TD124 that came to me (SN 13943) arrived with a dead motor coil. That motor refused to run. When I chose to use 13943 as my next restoration project I needed to do something to get a working motor. My immediate solution was to use the iron core with windings from another TD124 I have in inventory, sn 7888. This worked fine but caused me to search for another solution.
My solution turned out to be Simone Lucchetti. He lives in Rome, Italy. Simone operates a machine shop there and, incidentally, is an avid TD124 owner as well as a turntable designer/builder in his own right. Simone is well known among TD124 enthusiasts as a source for upgraded E50 motor coils. In his surveys he discovered that there was an undocumented revision done by Thorens to the E50 motor coils at around TD124 sn 40000. Long story made short; he found that Thorens increased the wire gage within the coils to reduce heat and increase power. All MKII motors have this revision. He duplicates this revision in his new replacement coil sets on offer. Here's a link to Simone's website: Simone Lucchetti http://www.audiosilente.com/
In addition to the benefit of having a replacement available for dead motor coils, Simone's replacement coils do offer enhanced motor performance. Having tried a pair of these myself I'm happy to write that these replacement coils are more than just a reproduction replacement. They are indeed a worthy upgrade to the first generation TD124. Most prominent among the enhanced performance attributes of the deck will be quicker start-ups from cold. Next, I notice a more robust sense of pace. Greater musical energy. More pop. Greater "jump factor". This I notice in comparison to both of my working TD124 players as well as any other TD124 I've had over here.
Plinth choices: The motor unit needs a plinth (cabinet) to fit within before you can begin playing records. There are some choices to be made. Heavy high mass plinths. Constrained layer builds. Light, hollow open box plywood type plinths. Ortofon ST-104 type open box in solid beechwood. Massive chunks of slate etc.
I do have a massive slate plinth. And I have used a couple of different open box plywood types. My take; The better the operating condition of your drive train, the less audible difference it makes. That said, the quietest operation I've heard was in slate.
When choosing a plinth one is also confronted with the question of whether to use the Thorens mushroom isolators or not. These mushroom shaped rubber 'bulbs' mount into the four height adjuster screws on the chassis and fit between chassis and plinth. To choose between using mushrooms or not is a matter left up to the individual. Going with mushrooms isolates the motor unit from its physical connections to the supporting structure. Opting to go without mushrooms means you allow vibrations emanating from the operating drive train, (and there are some) to flow into the cabinetry. Depending on how well the adjacent surface dampens vibrations, or doesn't, you might be able to make a clear choice between the two methods.
Personally I've tried it both ways, with/without mushrooms and on different
plinth designs. Solid slate. Open plywood box types. I think
the slate works better without mushrooms as the deck sounds quieter on slate
that way. On the open plywood box types it is another matter.
Really, the condition of the drive train plays into this. The healthier
the TD124 operates, the less drive train noise there is. And so it follows
that there is lesser need for
isolation and dampening. That said I can think of one setup I had with #2729 in
an open box plinth using mushrooms that did have a very energetic
delivery. I might set up like that again.
It is often suggested around the web that to alleviate any shell warp issues simply remove it from the player and replace it with a flat disk of some kind or another. Perhaps a thick 78 record with a thick platter mat on top. I've seen one firm that physically screws a machined flat disk of solid Delrin directly onto the iron flywheel of the TD124. That's right he drills and taps the iron platter to secure the Delrin plate. Other hobbiests have made similar suggestions. I am not offering any support to such methods. In fact I want to discourage this. For one thing, the TD124 was never intended to be operated in a start/stop manner. By design the motor is left running throught the listening session while using the clutch to engage/disengage the upper shell from the flywheel when changing records.
To deal with a warped upper shell the best solution nowadays, is to have the upper shell straightened by someone with the necessary skills to do so. Alternately there are a couple of sources for new replacement shells. These are not cheap to reproduce. One such replacement shell is offered by Mirko at ClassicTurntables.com. Another is offered by Schopper in Switzerland. These shells are machined from aluminum stock. The original shells were formed at the factory by two different methods. One was by spinning (an older method of shaping sheet metal into circular forms, the other was by die-stamping sheet aluminum.
Me...I straighten my own.
Notes on the magnetic attraction between the iron platter of the TD124 and certain moving coil cartridges.
I've found that there is a measurable magnetic pull* between the iron flywheel below and the cartridge above it. The only thing that can reduce this magnetic attraction is distance. And there isn't enough distance when using certain cartridges. This magnetic attraction between cartridge and flywheel can potentially mislead us when setting vertical tracking force of the arm/cartridge.
Below I offer a means to measure the strength of magnetic pull while using a DL-103R moving coil phono cartridge.
* The iron flywheel below does indeed attract cartridges fitted with stronger magnets. Typically moving coil cartridges will have a magnet within that is strong enough to attract itself toward the iron flywheel of the TD124.
Above photos illustrate one method of determining just how much magnetic pull there is with any given cartridge. Left photo; a digital scale with a means of measuring vertical force at record level. This scale is designed to be used while sitting directly on the platter mat.* Middle photo; taking a reading with the cartridge away from the iron platter below. Right photo; taking a reading with the cartridge in the area that is over the iron platter beneath. Difference between over iron and away from iron; 1/2 gram!
*(But not while sitting on a record. That would increase the vertical distance by the thickness of the record. If you did that your measurement wouldn't be as accurate as it is with the scale sitting directly on the mat.)
The solution to the magnetic pull problem was to set VTF using this particular scale directly over the platter mat and above the iron flywheel beneath. The magnetic pull is still there, but it will remain constant to your setting while the record plays. And now we know we are not putting too much force on the suspension of the DL-103R. Btw, too much tracking force can result in a hard to diagnose distortion.
Arms and Cartridges: On the TD124 we are restricted to two general effective lengths of tonearm. Nine inch and 12 inch. A 10 inch arm won't work because to set correct mounting distance its underneath parts will need to park into the outer framework of the TD124 chassis. And we are not going to cut into the cast aluminum chassis of the TD124 to fit a 10 inch tonearm! Nine inch or 12 inch. Nothing in between. Otherwise, the field is wide open. Below I'll just make note of some combinations I've tried.
For myself I want an arm and cartridge that will allow the turntable to deliver all of
energy within that record groove into the room. Not all arms and carts get this right.
If it is on the record you want sudden dynamics. If it is on the record you want drum hits to leap out into the room suddenly...... With
Pop! If it is on the record there should be tone, textures, fine details, inner details, air
and space between it all. Clarity.
Arms I've tried and notes about them.
Rega RB250 ** (Expressimo mods) with Uwe bodied DL103R. I've done some mass
tuning with this setup and liked it best when I could get the arm/cart to
resonate at around 9 - 10 hz using the hfnrr test record.
I've heard this arm using two different armboards. A 'painted black' chipboard
style of armboard and with a solid ebony board. The chipboard armboard produced
a faster, more energetic presentation. The ebony board seemed to enhance tones
and textures but seemed somewhat 'slower'. All very subjective
Graham 2.2 (round base) with Shelter 501-II: This makes a good partnership. The Graham and the Shelter pair up well together. The Graham is able to handle the resonant energy generated by the Shelter without being perturbed by it. I get a very energetic and "quick" sounding reproduction with this pair-up. Beautiful details, tones and texture. The Graham can dig up more detail than any other arm I've tried so far. It it is a revelation to hear. It gets the sense of musical flow right as well. Organic. Detailed and articulate. A nice combo.
The Zeta tonearm can get a bit edgy. It may indicate a problem with the arm in terms of maintenance (pivot bearings in need of clean/adjust) or it may point toward some well known issues that lie with the over-complicated counterweight of this arm. Many have said that by removing the outer decorative coverings of the counterweight, a new world of sound quality can be discovered with this arm. I'll experiment. Perhaps I'll make a different counterweight entirely, machined from Copper/bronze.
Fidelity Research FR54: I did a TD124 restoration for a customer that included one of these Fidelity Research arms. It is a high mass arm (16G effective mass) that is well suited for use with moving coil cartridges and their typically stiff suspensions. I thought the sound quality was quite good while using a DL-103R in a Uwe Panzerholz body and with a SS ruby / Fine-Line diamond re-tip. The standard FR headshell was used. Perhaps another headshell might have improved the output of this arm even further.
Maybe it was not quite as resolving as the same cartridge is
when mounted to the Zeta tonearm. But it is still very good and
affordable. At the time of this writing 2nd-hand FR54 arms can still be
acquired over the internet at prices comparable to or less than a new Jelco.
Beware that sometimes the cue mechanisms of the FR arm have been known to fail.
SME 3012 S2: Pricing on good examples of this arm have gone through the roof. Most who have tried it have suggested that it is more preferable to the shorter but otherwise similar 3009S2.
Fidelity Research FR64s/FR66s:
Vintage Ortofon arms: Some of these to be considered. I've yet to determine which ones are worth the effort and which ones are to be avoided.
The Thomas Schick tonearm: on my list of arms to try.
A few very good and rather expensive arms to consider.
Cartridges on my list: *
*note how all of my choices are moving coils and that to some degree or
another they will all exhibit a magnetic pull toward the iron flywheel of the
TD124. This I can accommodate simply by setting vertical tracking force
while using a scale directly above the iron flywheel beneath it. See above notes
on this subject above.