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My Thorens td124 journey

jan tomczak said:
Atm it isn't the main concern (tho it shouldn'tbe happening), it's my amp's error message (high frequency) that tells me to power off...and this happens when a record finishes in which i place tonearm in it's resting position, then turn to 0 from 33 or 45...then that electric noise or surge or whatever it is occurs.

for now, to play a record i turn to 33 from 0 (no problems) and when record finishes i place tonearm in resting position (no problems), i then switch amp off (no roblems) i can then turn to 0 from 33 without any problems...but of course i shouln't have to do it this way.
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No, you shouldn't, regardless, the end result looks great and your videos demonstrate that all is working to spec. What cartridge have you on the SME, BTW?
 
Craig B said:
No, you shouldn't, regardless, the end result looks great and your videos demonstrate that all is working to spec. What cartridge have you on the SME, BTW?
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Thanks, Been using the Ortofon 2m blue for over a year now, a very nice all-rounder.
ps: I wiil be taking the thorens to local repair man who is familiar with said turntable...i briefly explained the issue and it seems some kind of voltage spike thingy...it'll get sorted out soon once a proper look is had.
 
jan tomczak said:
Thanks, Been using the Ortofon 2m blue for over a year now, a very nice all-rounder.
ps: I wiil be taking the thorens to local repair man who is familiar with said turntable...i briefly explained the issue and it seems some kind of voltage spike thingy...it'll get sorted out soon once a proper look is had.
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I suspect that your local repairman suspects that there either isn't a mains switch suppressor fitted (which you've fit by way of the X2 cap across live and neutral at the switch) or that the existing one is faulty (unlikely, unless you are still getting a 'pop' on switch on).

Although it would need testing in situ (i.e. in your home with your amp and telly) it would be worthwhile testing deck switch off with the neon strobe lamp bypassed. The following drawing is quite informative as it illustrates how the lamp is wired in series with the motor coils, a copy of this (along with the one from yesterday) should give your repairman a good idea as to what connects to what and where, right through, including the motor coils.*

Thorens-TD124-motor-circuit.jpg

​
* This illustration should also help make clear why I was confident that your motor coils are sound, as green to green at commutator (for 200 to 250VAC operation) represents connecting via the first tap on each of the two coils (i.e. the full coil paths are in use).
 
Craig B said:
I suspect that your local repairman suspects that there either isn't a mains switch suppressor fitted (which you've fit by way of the X2 cap across live and neutral at the switch) or that the existing one is faulty (unlikely, unless you are still getting a 'pop' on switch on).

Although it would need testing in situ (i.e. in your home with your amp and telly) it would be worthwhile testing deck switch off with the neon strobe lamp bypassed. The following drawing is quite informative as it illustrates how the lamp is wired in series with the motor coils, a copy of this (along with the one from yesterday) should give your repairman a good idea as to what connects to what and where, right through, including the motor coils.*

Thorens-TD124-motor-circuit.jpg

​
* This illustration should also help make clear why I was confident that your motor coils are sound, as green to green at commutator (for 200 to 250VAC operation) represents connecting via the first tap on each of the two coils (i.e. the full coil paths are in use).
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Thanks, i'm sure that'll help him. Now, i'm not sure if this makes a difference to my wiring to the strobe...eg: have i engaged the 2 blue wires and 1 red wire in the correct strobe terminals as in the pic? What if i swapped them over...so engage red wire where the blue ones are and the 2 blue wires where the red one is? Have i got this bit wrong? Does it in fact make a difference as your diagram has different numbers/letters coming from the 2 motor coils? Hope what i'm saying makes sense...

Wiring to strobe as is

 
jan tomczak said:
Thanks, i'm sure that'll help him. Now, i'm not sure if this makes a difference to my wiring to the strobe...eg: have i engaged the 2 blue wires and 1 red wire in the correct strobe terminals as in the pic? What if i swapped them over...so engage red wire where the blue ones are and the 2 blue wires where the red one is? Have i got this bit wrong? Does it in fact make a difference as your diagram has different numbers/letters coming from the 2 motor coils? Hope what i'm saying makes sense...

Wiring to strobe as is

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Makes no difference as long as the short run from the switch conjoins with blue at the bulb socket. Usually this is a bit of black insulated wire, same as the run that comes from the mains block to the switch. The colours get a bit more confusing back at the commutator where blue branches out via red to the other end of motor coil #1, while red from the bulb socket connects the chosen voltage taps (green in this case) of each motor coil.
 
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I've had a call back from my local repair man (MC Electronics) in Bedford and the news is good, he's run all the tests and has said the 124 is in perfect working order.. no pops, no noise with connection from his amp/speakers. He has suggested bringing in my amp for a full test as that could possibly be the culprit.

Perhaps some kind of voltage issue... anyhow, the amp will be with him soon to carry out some tests.

The high frequency error that was shutting the amp dowm....Audionet error page

 
jan tomczak said:
I've had a call back from my local repair man (MC Electronics) in Bedford and the news is good, he's run all the tests and has said the 124 is in perfect working order.. no pops, no noise with connection from his amp/speakers. He has suggested bringing in my amp for a full test as that could possibly be the culprit.

Perhaps some kind of voltage issue... anyhow, the amp will be with him soon to carry out some tests.

The high frequency error that was shutting the amp dowm....Audionet error page

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It is all well and good to have the amp looked at, however, it would seem to represent a bit too much of a coincidence that the only thing affecting the pre is turning off the record deck. As you'll be shifting the amp anyway, suggest moving it as far away from the deck as possible and having another play at turning the deck off whilst the amp remains on. Should there exist no problem with amp when located further away then I think a ferrite ring round those bulb socket leads is the way to go, as success would indicate an RFI pulse through the aether rather than a spike via the mains. I suggest this because your amp is an Audionet SAM 20 SE, not despite it being one (i.e. what with there being firmware running within).
 
Craig B said:
It is all well and good to have the amp looked at, however, it would seem to represent a bit too much of a coincidence that the only thing affecting the pre is turning off the record deck. As you'll be shifting the amp anyway, suggest moving it as far away from the deck as possible and having another play at turning the deck off whilst the amp remains on. Should there exist no problem with amp when located further away then I think a ferrite ring round those bulb socket leads is the way to go, as success would indicate an RFI pulse through the aether rather than a spike via the mains. I suggest this because your amp is an Audionet SAM 20 SE, not despite it being one (i.e. what with there being firmware running within).
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Firstly, he'll be connecting the thorens to the amp to his speakers to see if he gets the problem that i was having, if yes, then we can gather that there is an issue with the amp.
He will then put the amp through some testing, tho he will test the amp either way. I'll wait until he calls with his findings.If everything is good from his end and not when it's back at mine then we can move forward with some of your suggestions Craig. We'll see when the goodies are back home...

Like i said upthread, no issues with the 401 in the same system...so all a bit odd to me!
 
jan tomczak said:
Firstly, he'll be connecting the thorens to the amp to his speakers to see if he gets the problem that i was having, if yes, then we can gather that there is an issue with the amp.
He will then put the amp through some testing, tho he will test the amp either way. I'll wait until he calls with his findings.If everything is good from his end and not when it's back at mine then we can move forward with some of your suggestions Craig. We'll see when the goodies are back home...

Like i said upthread, no issues with the 401 in the same system...so all a bit odd to me!
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I agree that it is a puzzler (hence my interest), especially so, considering that electrically speaking there is little difference between a 401 and TD124; each has a 2-coil shaded pole induction motor and a neon strobe, with the biggest differences being numbers of coil taps and the dropper resistor for one lamp being 5.6k vs. 33k for the other.

Looking forward to hearing what the service tech has to say.
 
Could it be worth replacing the resistor? It might have drifted out of spec/become noisy given its age and type (carbon comp I assume). FWIW I have a new one waiting to go into my 124 next time I strip it down to do anything, purely because the old one is janky looking and I know I can neaten up the wiring there with a much smaller modern metal film type.
 
Looks like carbon film on Jan's.

The more I look at it, the more his looks like brown, orange, orange, gold = 13k 5%. Then again, it could be orange, orange, orange, brown = 33k 1%. IIANM, 33k was the chosen value as it bridged the minimum vs. maximum values that were deemed necessary between the primary mains markets, Euro/UK/Antipodes vs US/Canada/elsewhere. This wasn't indicated in the Mk I/II service manual but came to light (ha!) with the Papst motor service information sheet no. 22 as follows...

220V - 240V: 33k - 82k 1/2 Watt
100V - 125V: 10k - 33k 1/2 Watt​

BTW, this is a shunt resistor for the neon lamp, nothing to do with motors.

IMG_2539.jpg
 
Craig B said:
Stumbled upon a nicer schematic/wiring diagram than the drawing posted previously.

ve-thorens-td124-mkii-wiring-diagram.png
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Ok,

Had a good chat with the testing/repair situation… The Audionet amp seems a bit of an odd/unusual design from his findings with the main point being it is overly sensitive to any spike or surge, thus explaining the ‘thump’ sound coming through the speakers when switching off to 0 from any rpm on the Thorens, even with the amp’s volume turned right down. He didn’t think the ‘ferrite ring’ option would make any difference to the issues (his explanation was too technical for me to remember).

His only answer as to ‘how to overcome’ the issue was to fit an outboard switch to turn off the Thorens if the amp was still powered up…but then that’s not too different to switching amp off before switching to 0 from say…33rpm on the Thorens. He couldn’t explain why the 401 didn’t give me any issues with the same amp…

As mentioned before, the thorens with his denon amp and speakers there was no issue. He will email me the specifics of his tests in due course.

I do have a spare receiver I could use for the time being as an option but no phono stage….any recommendations ? ‘I’m using an ortofon 2m blue so something that would work nicely with it’s spec…

So, Thorens is fine and amp is fine….they just don’t like each other!:rolleyes:
 
I wouldn't discard the Audionet just yet, Jan, that is, unless you were thinking of putting the Thorens in a second system anyway.

The tech's findings are mostly as expected. The SAM 20 SE appears to be a very good analog amplifier with a less than necessary digital control system/user interface.

The suggestion to try a ferrite ring as suppressor at source was just a virtual no cost shot at possibly solving the issue. I would have expected the tech to suggest fitting such filter(s) within the amplifier, particularly on the ribbon lead(s) that connect the control electronics. These are available for flat ribbons in a clamp on format. Personally, I'd double down and fit a round ferrite clamp to the amp's power lead as well.

 
Craig B said:
I wouldn't discard the Audionet just yet, Jan, that is, unless you were thinking of putting the Thorens in a second system anyway.

The tech's findings are mostly as expected. The SAM 20 SE appears to be a very good analog amplifier with a less than necessary digital control system/user interface.

The suggestion to try a ferrite ring as suppressor at source was just a virtual no cost shot at possibly solving the issue. I would have expected the tech to suggest fitting such filter(s) within the amplifier, particularly on the ribbon lead(s) that connect the control electronics. These are available for flat ribbons in a clamp on format. Personally, I'd double down and fit a round ferrite clamp to the amp's power lead as well.

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There's certainly no negatives in trying the ferrite ring for sure...can you send us a link as to what i should get please. Also, could a ferrite be fixed on the power cord aswell?
 
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