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Thorens TD-124/II restoration / upgrade

Import Duty and VAT for the Swissonor platter and top platter came to less than £60, which was a relief. I've installed both of them, together with my new Martin Bastin PSU. The TD124 now runs fairly sweetly and accurately after the eddy brake magnet was removed - the adjustable voltage and frequency of the new PSU takes care of motor speed. There's definitely scope for making the drivetrain more quiet and, like Tony, I reckon that the stepped pulley is probably the main culprit, so I am looking at new bearing materials (possibly plastic) for it and the idler wheel.

The Swissonor non-magnetic ferrous platter is a beautifully made thing, with a very accurately machined spindle hole that obviates the need to set the platter up for minimum runout each time it's disturbed. The original platter design is rather crude in comparison.

It's a shame that I won't be able to listen to the deck for some time, since I and it are 160 miles away from the rest of the system for a while. Plenty of time to get the thing running sweetly!
 
So , actually what's left from original table , a label? I didn't follow the whole thread but can you sum up the costs so far ? , (just asking since I have a nice example of TD124 and lightning does strike people from time to time :)
 
So , actually what's left from original table , a label?

It's something you can take as far as you like really. Here's the Schopper site, mine has both replacement platters, the main bearing upgrade, and is currently in for a full refurbishment (mainly due to the stepped-pulley bushings being shot). It will end up a lot better than it was when new. As stated earlier this isn't something one embarks on to get 'a bargain record deck' or whatever, those of us who go down this path do so because we'd far prefer to own a maxed-out 124 to a SME, Oracle, WT, VPI or whatever. For me the 124 is the most aesthetically /ergonomically perfect and arguably the most historically significant record playing device ever created (a case could obviously also be made for the 301 and EMT 930 too). It is the deck I most want to own. Period. There is nothing quite like taking an original Impulse, Blue Note or wide-band deep-groove SXL and placing it on the state of the art device from that golden period of vinyl creation and replay. It is just the right tool for that particular job, and as a geeky record collecting jazz fan that really appeals!
 
Yes, I understand you completely. Its like deciding you want a Norton Commando or a Vincent Black Shadow or a Mk.2 Jaguar because that is what you want! And then going into all the upgrades and improvements and bug-solutions that a few decades of experience, combined with evolution in materials and machining technology may have made available. Its about passion rather than rationality, which is as it should be.
 
So , actually what's left from original table , a label? I didn't follow the whole thread but can you sum up the costs so far ? , (just asking since I have a nice example of TD124 and lightning does strike people from time to time :)

Please understand that my TD124 came with a truly horrible glass mat, without a top platter, and was fitted to a functional but crude and ugly plinth. So, part of my restoration work has been to bring it back to a 'period' look with the correct top platter and 'Ortofon' style plinth.

What's left? The un-restored chassis, motor, main bearing housing, stepped pulley, idler wheel (second hand), all the controls. And the label.

The original motor has been rebuilt; the original main bearing has a bronze end cap from Jim Campbell in the States (eBay seller jec965); the new Ortofon style plinth is also from Jim, as is the armboard. I did buy a used top platter off eBay but that was bent and cost nearly as much as the new Swissonor one. Service items have included new motor suspension grommets, lubrication and a new belt. The PSU and new platters are presents to myself after a little over 6 months serving in Afghanistan this summer.

I'm not going to sum up the costs. Suffice to say that I bought the TD124 because a friend had one and it was by far the finest record player that I had ever heard, at any price. It is also delightfully small, and does not dominate the equipment rack. I like that as much as the period charm of operating levers and feeling the mechanism working underneath.
 
Don't care what it sounds like. The TD124 is a classic and you can keep all these overpriced bling decks ;) Not the point at all :D
 
Time for an update as a few things have occurred since my last post. All the following should obviously be read with the knowledge that I am the most picky person on the planet and zone in on things that most people would never notice, let alone pay a bloody fortune to put right...

I got the deck back from Schopper, and in fairness to them it was a little quieter than when I sent it, but I still wasn't happy with it (still a lot noisier than either the 301 or Lenco L70). Annoying as their work was around £400 or so (nothing about TD-124s is ever cheap IME). They'd stuck a couple of resistors into the plinth to drop my high mains voltage down a bit, but even so the stepped pulley still did it's chattering thing and I still suspected the bearings (which annoyingly they couldn't change despite the claims on their website as apparently there are "different types"). All in all not a great experience, but the deck was quieter than it was, and if I used a lightbulb as well, very quiet indeed.

That was until late last week when I spotted what looked like a nice condition chassis on eBay (link). I found myself clicking the Buy It Now figuring it would either fix the issue or at least give me a spare chassis to send to a machine shop to get some custom bearings made and fitted. It turned up this morning and is indeed in very nice condition, I'd say just a smidge better than the one I have already, which is very nice indeed, I'd grade it as a very tidy EX/EX, just the usual slight paint crazing around the main bearing from an oil-leak, but they all seem to have that, and you can't see it anyway. I gave it a good clean and I'm very pleased with it:

8631998942_5621a092c5_o.jpg


It's a little later than my existing one with (9268* vs. 8569*) and I suspect one of the very last 124s ever made.

8631999100_0dc2acd783_o.jpg


The underside is very clean too, no visible wear to the support posts etc.

I spent the weekend reading absolutely everything on the whole internet to prepare myself for the task of completely stripping the deck down and rebuilding it into it's new home. Time well spend for sure as I'm certain I'd have broken the fragile metal control-band etc had I not understood exactly how to remove it (one removes the speed lever mech, metal belt and cam assembly as one single entity, very carefully rather than removing the belt itself).

Anyway I've successfully done the chassis transplant. It's all back together with no hitches, breakages or bits left over at all. I took all my time very carefully cleaning every single part too, so it's as clean and shiny as it can be. I'm now leaving it running for a while, I'll give it a few hours. At the moment it is running nice and quietly (about as quiet as the other chassis did with resistors and light-bulb), though it's early days yet as all the oil may well fall out, but certainly positive so far. It's been a really good learning curve too, I now feel a lot more confident about the deck now I've had it stripped-down to component level. I'm rather chuffed with myself for not bollocksing anything up! Will report back later once it's been up and running for a good while.
 
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Excellent work Tony.

So the new chassis without resistors and bulb is as quiet as the old one with?

How are the stepper bearings lubricated?
Can you use a thick grease instead of oil?
 
I really like the speed dial on that chassis. I'm getting an itch to buy a nice 124, but they seem to be very pricey. What would be a fair price for a nice example?
 
Excellent work Tony.

So the new chassis without resistors and bulb is as quiet as the old one with?

How are the stepper bearings lubricated?
Can you use a thick grease instead of oil?

I think I spoke too soon, it's quieter than it was, but some noise has certainly returned. What I'm describing here is just mechanical transport noise, not rumble though the speakers - a kind of whirring noise audible from a few feet away that increases the more the eddy current brake is brought into effect. With the eddy current brake disabled the deck is all but silent, certainly as quiet as the 301 (which is very quiet indeed). I'm obviously not comparing like with like here as the 301 is mounted in a heavy slate plinth, the 124 in a light-weight ply hollow plinth decoupled by it's rubber mushrooms. I'm beginning to think it's simply a noisy design in the really high voltage conditions of my home - I've just measured the mains at 251v!. The 40w lightbulb trick drops it down to 228v, but it still needs a lot of eddy current brake there to drag it down to 33rpm (almost full-on). My next plan is to find a spare motor pulley and get a machine shop to knock a mm or so off it, that would drop the speed without friction. It would just be a matter of figuring out the right amount to get machined-off! As a start point I'll try flipping the one I've got over onto the US (60Hz) setting and see how much too slow that is!

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I'm not disappointed as if anything it rules the step-pulley bushings out and probably means both chassis assemblies are ok, plus I'm not a lot more confident in my servicing abilities with regards to this deck. It also means I've got a nice chassis to sell at some point...

It sounds great, a softer more 'analogue' sound than the 301, not as dynamic, but maybe even more solid pitch-wise, but too many variables to draw any real conclusions (arm, plinth, cart, phono stage - I'm using the 834P with the 124 so as I can switch between them easily).
 
Anyway, I am under the impression that Swissonor also builds or at least has built a rather nice power supply for the TD 124 - as per the attached picture. I guess it would also be rather expensive.

DSC_9981.JPG

Any of our electronics-literate folk care to speculate what might be in that PSU conceptually, i.e. how exactly would it control the motor speed? Are we looking at a very fancy variac here or is it likely to be doing something with mains frequency too?

I still think my most logical / neatest approach is to find a spare motor pulley and get someone with a lathe and appropriate skills to skim a couple of percent off the running edge as that would keep all that nice idler-deck torque but still mean I could really back the eddy-current brake off to a more sane setting, but I'm still curious as to what this type of PSU might be doing. I think Dr Martin Bastin makes one too.
 
I have found, using my Martin Bastin PSU, that the TD124 needs something like 230v to retain its vibrancy and 'drive', otherwise if the voltage is reduced further, it just sounds very dull. Luckily, the Bastin PSU has a frequency adjuster, so it's easy to set the voltage for best sound, then bring the speed down with the frequency knob. The Swissonor PSU appears to have just one control for voltage adjustment, so it would not do for me.

Tony - you could try using a Power Inspired AG500 or AG1500 mains regenerator, since the output voltage is configurable.
 
Do you know how much too fast the deck is running? And are any of the motor pulley/stepped pulley/platter drive surface non-original?

The motor runs at a maximum speed controlled by the frequency, in reality just a touch slower. This speed will be negligibly affected by the voltage since the power required just to drive the platter is relatively small compared to that absorbed by the brake. So a measurement of this speed would confirm that everything was to spec, and the spec suggests 34.3rpm, 33.3 + 3%.

The most precise method of measuring the speed might be to record any old test disc tone at a stroboscopically accurate 33 1/3 and then again at max. I can analyse the resultant frequencies quite accurately. Or Audacity is probably good enough.

Paul
 
Do you know how much too fast the deck is running? And are any of the motor pulley/stepped pulley/platter drive surface non-original?

All running surfaces (bar the platter) are original and in superb condition. I've actually got three stepped pulleys, and the motor pulley has to be entirely stock as all one could do with it is make it smaller, and that would make the deck run more slowly. The modified aspects of this deck are the main bearing (Schopper) and both platters (Swisonor), these are detailed earlier in the thread. It's always needed a huge amount of eddy-brake compensation to get it to run to speed regardless of whether the Swissonor platters are fitted or the original Thorens. I need it pretty much full-on to get it slowed to 33rpm unless I drop the mains voltage quite a lot.

Whilst I no longer have the means to record the deck (Apple annoyingly removed the line-in from the current range of Macbook Pros) I do have a guitar tuner on my iPhone that indicates Hz. I'll have a go with that later with my copy of HFS69, which annoyingly is a little eccentric, I should be able to get a rough indication though.

I've just migrated Schopper's resistors from the old chassis (they were lightly glued-in) to my lightbulb voltage dropper:

8634457328_269e73fc15_o.jpg


As a temporary arrangement, but it works and leaves the deck itself 100% un-bodged. This certainly enables it to run quietly. My only concern is the resistors get quite hot after a while, but I'd prefer them to get hot here in a cheap lamp than in a valuable TD-124. I've cable-tied them to the ceramic lamp socket so they should be ok - they don't get hot enough to burn skin, just the stage you'd not want to keep your fingers on them. As the circuit is only made when the deck itself is switched on there is no risk at any other time. I still think finding and modifying / commissioning a new motor pulley is the way forward though.
 
Some tuner readings using Cleartone on my iPhone:

Correct pitch as indicated by strobe 295hz
Full voltage, eddy current brake set to minimum, i.e. deck free-running 306Hz

The test tone on disk is allegedly 300Hz, so why I'm getting an under-reading from the meter when the strobe indicates correct speed is anyone's guess! The records a little eccentric so I've gone for the middle range.

This is actually one of the tracking test bands on HFS69, the wow and flutter band seems to be too high in pitch (3khz) for the meter to accurately read (it was indicating the signal was an octave below at around 1500hz).
 
So max is 3.7% fast (306-295)/2.95, which isn't a clear indicator of anything mechanical being out of tolerance.

Which is good.

The service manual suggests you can adjust the range of the brake, but this won't do anything for the noise, just the aesthetics.

It would be interesting to know the value of your resistors, and what the voltage across the motor is. Is there any possibility that the motor is wired for 125-150v?

Paul
 
So max is 3.7% fast (306-295)/2.95, which isn't a clear indicator of anything mechanical being out of tolerance.

Which is good.

The service manual suggests you can adjust the range of the brake, but this won't do anything for the noise, just the aesthetics.

It would be interesting to know the value of your resistors, and what the voltage across the motor is. Is there any possibility that the motor is wired for 125-150v?

As you suggest adjusting the physical position of the eddy-current on the chassis magnet does nothing for the noise, the issue is that so much resistance is required it causes some audible vibration in the drive-chain. I've always suspected the step-pulley bushings, but given similar results from two similar close to mint condition chassis I guess JCBrum's suggestion earlier that it may be the motor coils vibrating may deserve a little more investigation, though that's probably getting out of my comfort zone. I also have a very strong 'restore, don't modify' attitude to vintage kit and I really don't fancy gluing anything to such a rare and valuable motor. Everything I've done to this deck (upgrade platters, bearing etc) can easily be undone with a screwdriver. I still think the best solution is to find another motor pulley (it just bolts onto the motor spindle with two set-screws) and get someone to lop say 2.5% off it on a lathe. Either that or get someone to actually make me a new one from scratch, I imagine it would only take someone who really knew what they were doing an hour or so. Alternately just run the deck on the lightbulb mod or buy a cool looking cased variac, should such a thing exist.

I don't know the values of the two resistors Schopper installed, though in conjunction with a 40w bulb the voltage is dropped to about 199v based on a measurement a few minutes ago. At this voltage the deck needs very little eddy-current brake (still a little, i.e. one can still speed it up) and runs very quietly indeed. It's certainly a perfectly usable compromise.

If you meant the resistors on the deck's voltage selector I have no idea at all. I've left that all well alone aside from swapping in a new spark suppression cap when I first got the deck. Here's a picture of the underside of the voltage selector I took before cleaning it up yesterday in case I broke anything!

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One thing that Schopper said was that, despite having a 250v setting, TD-124s are really not happy at that voltage at all, they reckon 220 or so is about optimal. My voltage is at the high-end of UK spec, I measured it at 251v yesterday.
 
If getting an lsd shot everyday is what you want from your music replay, than that farting idlers with their mechnical ,monotonous drive can serve a good substitute:D and I'm pretty shure fans of Satchmo and Diango Reinhard are ballistic about it. I did not hear SME but better Oracle is on different planet from any idler I heard , old or recent. I remember how proud I was from my loosely Shindo inspired Thorens update , drive was quiet , bearing tide so I took it to my friendly dealer with SOTA Audio research and Magnepan setup (not actually my cup of tea and inspite of sky high prices would not get it for free , unless to impress friends) . They looked at that table and exchanged half smiles . We played it and it sounded like you know OK !!!. Than they hooked up budget VPI with comparable arm and comparable $500 cart , well let me say that I offered to vacuum their sale room in exchange for an eye opening experience. I'm not saying that the table is total junk , it has its momements (actually one moment, very primal and appealing to many listeners) it's just nowhere near the cult status it's aproaching . My next visit was with my "quietest , one of the best LP playback ever at any price point ".. the pride of British industry and reviewer's whore . mighty Rega P9 I couldn't get to terms with. Dealer who was not that familiar with Rega's bazilion models looked it briefly up , we played it and he said:... well , actually not that bad for cheap Rega (I didn't tell him it's a $5k table so he thought it's a just REGA you know) Than we put to use Oracle table and Sayonara !! Since I vacumed the floors last time I just did the shop window
and never came back with any other table ,but thats another story and axe to grind while drinking whatsever left at home and trolling on the net when the Girl is out :D

Hi L,

I'm late to the party as always on this thread - but after reading it, it seems as if you're referring to Harry Francis the owner of Audio Dimensions over in Royal Oak, Michigan with the Sota/VPI/Oracle Tables and Audio Research and Maggie's?.

Could this be the joint you're talking about?.

Just curious if nothing else.

o_O scar
 
I can't figure out from the picture and the online wiring diagram whether that is 'correct' or not.... But if it's coming good at 200v it's probably right.

Both solutions are a bit unsatisfactory, the deck should be right at UK normal mains, the contemporary reviewers didn't suffer the problem.

Paul
 


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