Usually a symptom of incorrect lubricant, slightly thicker than nominal belt, high mains voltage or misadjustment of the eddy current brake magnet relative to the intermediate pulley. Also if the magnet is weak the brake will not work correctly. (I have seen just a couple of weak magnets over the years)
I am not sure about the latter half of your question are you talking about a (Thorens) arm or something else?
I am not sure about the latter half of your question are you talking about a (Thorens) arm or something else?
Thank you Kevin,
Is it acceptable to use the tt after having put several drops to motor upper and lower oiling points ? I avoid to open it so to fully restored it as I am not sure of I can adjust the rotor properly...If you agree to use it as it is , then I stay as I am now. It stops after 15-17 seconds without belt. Is it acceptable? Before that lubrication is was 2-3 seconds...and I immediately turned it off and lubricated it several times so to increase from 3 to 8, after a minute I put 2 more drops and after 2 minutes it stopped in about 15-17 sec.
I will try to check what is happening of those you kindly advised me.The most difficult is to check if the magnet of the eddy brake is weak or strong.
I meant, the tt's circular bubble for obtaining the level of the 124 MKII has lost it's liquid.
How to fix that issue?
Is it acceptable to use the tt after having put several drops to motor upper and lower oiling points ? I avoid to open it so to fully restored it as I am not sure of I can adjust the rotor properly...If you agree to use it as it is , then I stay as I am now. It stops after 15-17 seconds without belt. Is it acceptable? Before that lubrication is was 2-3 seconds...and I immediately turned it off and lubricated it several times so to increase from 3 to 8, after a minute I put 2 more drops and after 2 minutes it stopped in about 15-17 sec.
I will try to check what is happening of those you kindly advised me.The most difficult is to check if the magnet of the eddy brake is weak or strong.
I meant, the tt's circular bubble for obtaining the level of the 124 MKII has lost it's liquid.
How to fix that issue?
I would have thought that 15~20 seconds for the motor to stop is fine. The only disadvantage of not stripping the motor down is that you cannot be sure how much oil is being absorbed by the felt washers to provide long term lubrication, so you might have to apply oil a little more frequently.
As far as the magnet strength is concerned, I wouldn't be too worried yet, just try to move the magnet closer to the idler pulley; a couple of thicknesses of paper should be enough clearance. Only if this makes no difference to the speed then you might have to consider a replacement magnet.
Good Luck, and enjoy your turntable
As far as the magnet strength is concerned, I wouldn't be too worried yet, just try to move the magnet closer to the idler pulley; a couple of thicknesses of paper should be enough clearance. Only if this makes no difference to the speed then you might have to consider a replacement magnet.
Good Luck, and enjoy your turntable
Thank you Ralphcooke very much
I will approach the magnet closer to the stepped pulley as you advised me and let you know. Also I will add some 3-4 drops to motor lub points so to be sure that is well absorbed. It is encouraging that I can use it without to open the motor etc and that there will be no any risk for motor's life
Thanks again
I will approach the magnet closer to the stepped pulley as you advised me and let you know. Also I will add some 3-4 drops to motor lub points so to be sure that is well absorbed. It is encouraging that I can use it without to open the motor etc and that there will be no any risk for motor's life
Thanks again
Actually I would recommend a motor tear down and rebuild, since the bushings are low hours they can be retained. Not doing so means two things, the first is that the bushing pores are clogged with congealed/solidified oil and the felt has become pretty non-absorbent. Long term lubrication is not assured. Scoring of the motor shaft can eventually occur. The procedure for servicing the bushings is outlined elsewhere in this thread and is worth performing.
I'm not a fan of the Schopper oil, but of the commonly available replacement belts the Schopper is amongst the very best, which is not to say necessarily that it is entirely good enough. (IMHO it is a bit too thick)
These motors when properly lubricated will coast substantially longer than the 15 - 17 seconds you mention, Volken or user 510 might have some input. Both of my rebuilt motors coast for about 22 - 25 seconds depending on how warm they are.
Are you running on 50Hz or 60Hz power? Edit: Never mind I see you are in Greece..
I'm not a fan of the Schopper oil, but of the commonly available replacement belts the Schopper is amongst the very best, which is not to say necessarily that it is entirely good enough. (IMHO it is a bit too thick)
These motors when properly lubricated will coast substantially longer than the 15 - 17 seconds you mention, Volken or user 510 might have some input. Both of my rebuilt motors coast for about 22 - 25 seconds depending on how warm they are.
Are you running on 50Hz or 60Hz power? Edit: Never mind I see you are in Greece..
Thank you Kevin.
It is 50 Hz ...Greek crisis..230 voltage . The only way to stay alive from crisis is to hear some good music doing this way a therapy ....
I really understand what you kindly advised me to do regarding the motor in order to keep it like new for years. The 124 MK II that was gifted to me is in mint condition but as you said ,due to decades old oil in the sintered bronze pores, these are clogged and new oil can not be inserted. So no way to work as sintered bronze bushings, but just as bushings with no pores...
The same problem for the main bearing bushings...
To my first 124 MKII I had put new oil in the main bearing but when I checked it after 6-8 months, I was shocked because I saw it greenish .. and smelling bad. I then realised that new thin Schopper oil had day by day reacted as remover to the molecules of the old old greasy oil of the bushings pores.
So the only solution is to follow the correct proper difficult way and not the easy way.
Schopper oil is too expensive to use it in quantity in order to boil the motor bushings , so the old oil come out and new oil to be inserted in the pore.
If I use, for boiling-removing the old oil ,any motor oil about SAE 20 that is inexpensive compared to Schopper oil ,that could be ok. But after that if i put Schopper oil this will just cover the surface of the bushings ,as the previous lets say SAE 20 motor oil has filled their internal pores. Is it possible a chemical reaction of the two different kinds of oil to be occurred and affect the proper lubrication? All it's bushings are in mint condition and I will avoid to replace them with new.
Your advices are needed and will be helpful.
Thanks again
It is 50 Hz ...Greek crisis..230 voltage
. The only way to stay alive from crisis is to hear some good music doing this way a therapy ....I really understand what you kindly advised me to do regarding the motor in order to keep it like new for years. The 124 MK II that was gifted to me is in mint condition but as you said ,due to decades old oil in the sintered bronze pores, these are clogged and new oil can not be inserted. So no way to work as sintered bronze bushings, but just as bushings with no pores...
The same problem for the main bearing bushings...
To my first 124 MKII I had put new oil in the main bearing but when I checked it after 6-8 months, I was shocked because I saw it greenish ..
and smelling bad. I then realised that new thin Schopper oil had day by day reacted as remover to the molecules of the old old greasy oil of the bushings pores.So the only solution is to follow the correct proper difficult way and not the easy way.
Schopper oil is too expensive to use it in quantity in order to boil the motor bushings , so the old oil come out and new oil to be inserted in the pore.
If I use, for boiling-removing the old oil ,any motor oil about SAE 20 that is inexpensive compared to Schopper oil ,that could be ok. But after that if i put Schopper oil this will just cover the surface of the bushings ,as the previous lets say SAE 20 motor oil has filled their internal pores. Is it possible a chemical reaction of the two different kinds of oil to be occurred and affect the proper lubrication? All it's bushings are in mint condition and I will avoid to replace them with new.
Your advices are needed and will be helpful.
Thanks again
Thank you Kevin.
It is 50 Hz ...Greek crisis..230 voltage
I really understand what you kindly advised me to do regarding the motor in order to keep it like new for years. The 124 MK II that was gifted to me is in mint condition but as you said ,due to decades old oil in the sintered bronze pores, these are clogged and new oil can not be inserted. So no way to work as sintered bronze bushings, but just as bushings with no pores...
The same problem for the main bearing bushings...
To my first 124 MKII I had put new oil in the main bearing but when I checked it after 6-8 months, I was shocked because I saw it greenish ..
So the only solution is to follow the correct proper difficult way and not the easy way.
Schopper oil is too expensive to use it in quantity in order to boil the motor bushings , so the old oil come out and new oil to be inserted in the pore.
If I use, for boiling-removing the old oil ,any motor oil about SAE 20 that is inexpensive compared to Schopper oil ,that could be ok. But after that if i put Schopper oil this will just cover the surface of the bushings ,as the previous lets say SAE 20 motor oil has filled their internal pores. Is it possible a chemical reaction of the two different kinds of oil to be occurred and affect the proper lubrication? All it's bushings are in mint condition and I will avoid to replace them with new.
Your advices are needed and will be helpful.
Thanks again
Best to use the Schopper oil with new bearings only , I use Mobil oil for the old bearings its thicker then the Schopper no problems with chemical reactions. As Kevin said first motor revision , I have 230 Volts also mosttimes no problem ,can you measure the speed from the motor ?
I can measure your strength for the magnet if you like .
Thank you Volken very much.
Do you recommend to use Mobil (what type?and what viscosity?) in order to boil with that oil the motor bushings so the old oil that stays inside the pores to be removed and the fresh oil to fill the pores?
Regarding main bearing:
I do not know if it would be acceptable to put the complete main bearing (as it is without to remove its bushings ) inside a bath of warm Mobil oil about 80 degrees Celsius in order to remove old oil so the new to fill the pores. Is it safe for the complete bearing to be used like that? I think there is no risk as temperature of 80 degrees Celsius is not high. Any idea will be helpful .
These days I will try to find the time and patience ..to adjust the eddy brake magnet position to see if that is the reason of the faster speed. If not I will let you know.
I love the 124 and its life like sound performance much more that any other turntable even the very very expensive ones. Most of modern tts sound like CD players , without soul, without that emotional heart of the 124 ,without emotions,dynamics , PRAT and without that melodic and pure organic sound of the 124. I love it and I want to do my best for that ..companion ..of my musical and emotional hours of pleasure.
Thank you for advices and your time to answering
Do you recommend to use Mobil (what type?and what viscosity?) in order to boil with that oil the motor bushings so the old oil that stays inside the pores to be removed and the fresh oil to fill the pores?
Regarding main bearing:
I do not know if it would be acceptable to put the complete main bearing (as it is without to remove its bushings ) inside a bath of warm Mobil oil about 80 degrees Celsius in order to remove old oil so the new to fill the pores. Is it safe for the complete bearing to be used like that? I think there is no risk as temperature of 80 degrees Celsius is not high. Any idea will be helpful .
These days I will try to find the time and patience ..to adjust the eddy brake magnet position to see if that is the reason of the faster speed. If not I will let you know.
I love the 124 and its life like sound performance much more that any other turntable even the very very expensive ones. Most of modern tts sound like CD players , without soul, without that emotional heart of the 124 ,without emotions,dynamics , PRAT and without that melodic and pure organic sound of the 124. I love it and I want to do my best for that ..companion ..of my musical and emotional hours of pleasure.
Thank you for advices and your time to answering
Thank you Volken very much.
Do you recommend to use Mobil (what type?and what viscosity?) in order to boil with that oil the motor bushings so the old oil that stays inside the pores to be removed and the fresh oil to fill the pores?
Regarding main bearing:
I do not know if it would be acceptable to put the complete main bearing (as it is without to remove its bushings ) inside a bath of warm Mobil oil about 80 degrees Celsius in order to remove old oil so the new to fill the pores. Is it safe for the complete bearing to be used like that? I think there is no risk as temperature of 80 degrees Celsius is not high. Any idea will be helpful .
These days I will try to find the time and patience ..to adjust the eddy brake magnet position to see if that is the reason of the faster speed. If not I will let you know.
I love the 124 and its life like sound performance much more that any other turntable even the very very expensive ones. Most of modern tts sound like CD players , without soul, without that emotional heart of the 124 ,without emotions,dynamics , PRAT and without that melodic and pure organic sound of the 124. I love it and I want to do my best for that ..companion ..of my musical and emotional hours of pleasure.
Thank you for advices and your time to answering
In the time I bought this oil it was a direct replacement for the Caltex Thorens oil no specs on that sorry but if I can help you on send me a pm.
Main bearing boiling in the oil is no problem but better remove the old bearings you get much lower wow figures !
Don't use motorcar oils. Often the additives are not ideal ( forming phosphoric acid crystals ). Esso Research agreed with Dr Edward Bowers on this. Simple SAE 30 with no additives is best. 80C seems fine. Exxon- Esso are also Mobile and Comma oils. Edward Bowers was a Prof at British Non Ferrious Metals in Grove Wantage UK. His team perfected the Fuel cell in 1952 which was sold to NASA ( P&W ). Sadly Eddy is in a care home now and has no idea of his past. He is 89. His boss Francis Bacon who claimed to be a decendent of the man of the same name. Esso was at Abingdon at the time and loved helping Garrard. Wow usually is idler or belt related. Drag is also very helpful as long as not excessive. If a bearing is made with less clearence the warm up time is longer. Drag is good because it becomes a greater factor than stylus drag. The magnetic brake also is much like drag although how it works has a different graph.
Remember the gap between the shaft and bearing outer is quite large. This is correct as otherwise the drag is too high. I haven't measured a TD124 shaft. I suspect the outer is a standard metric size which will be highly accurate regardles off supplier. They are pressed molded in a die. As it is costly to make the die no one will make it less than perfect. A machined part no matter how well made usually is less good. This being so, only the oil is important given the the bearing fit is correct. The surface finish whilst nice to see is not a key factor. Nor is the hardless except the ball ( shaft > 55 Rockwell C and ball > 70 ). The ball can be tapped around to have a new contact. Even the shaft being oval is OK as long as it is inside a reasonable limit. The shell must be perfect and always is if handled with care when insertinting. In the ideal world the shell receiving surface is lapped to be an easy fit. Then use retainer to fit. Use the shaft as a alingement tool whilst the compound is setting, do one at a time to aid the alignement. Be certain no retainer gets on the shaft interface. The compound is compatible with oil which is both good and bad. For this reason a machined shell no matter how good is not likely to meet the original design goals. The shaft no matter how good will be oval. If both are oval that is unlikely to work well. No Oilite shell I have seen is less than excellent. Some are 2 for $1 or less. Low cost 6mm shafting is often 5.995 mm, that's a typical running fit for 6 mm Oilite.
This is about right and is sister company to Mobile. Haven't used it myself so must trust the description.
https://www.nielsencdg.co.uk/acatal...05L-SAE-30-Motor-Oil-5-Litre-COM_CLA305L.html
Remember the gap between the shaft and bearing outer is quite large. This is correct as otherwise the drag is too high. I haven't measured a TD124 shaft. I suspect the outer is a standard metric size which will be highly accurate regardles off supplier. They are pressed molded in a die. As it is costly to make the die no one will make it less than perfect. A machined part no matter how well made usually is less good. This being so, only the oil is important given the the bearing fit is correct. The surface finish whilst nice to see is not a key factor. Nor is the hardless except the ball ( shaft > 55 Rockwell C and ball > 70 ). The ball can be tapped around to have a new contact. Even the shaft being oval is OK as long as it is inside a reasonable limit. The shell must be perfect and always is if handled with care when insertinting. In the ideal world the shell receiving surface is lapped to be an easy fit. Then use retainer to fit. Use the shaft as a alingement tool whilst the compound is setting, do one at a time to aid the alignement. Be certain no retainer gets on the shaft interface. The compound is compatible with oil which is both good and bad. For this reason a machined shell no matter how good is not likely to meet the original design goals. The shaft no matter how good will be oval. If both are oval that is unlikely to work well. No Oilite shell I have seen is less than excellent. Some are 2 for $1 or less. Low cost 6mm shafting is often 5.995 mm, that's a typical running fit for 6 mm Oilite.
This is about right and is sister company to Mobile. Haven't used it myself so must trust the description.
https://www.nielsencdg.co.uk/acatal...05L-SAE-30-Motor-Oil-5-Litre-COM_CLA305L.html
Last edited:
Wow in the TD124 at 33 rpm is caused by first the mainbearing at 0.55 hz
idlerwheel at 1,6 hz and belt at 7 hz the two latter ones producing a lot off harmonics in the flutter spectrum too.
If you replace the bushings you get lower wow figures can show that with speed spectrum measurements but I done this before in this group.
Oil same story lot has been said about it but difficult to find it back for new users .
Yes you need special tooling for replacement these bushings done a lot measurements on these shafts etc. now working on the 401 rev. going compare these with the 124 concerning clearance etc.
Castrol has about the same, also 20W-50 but thats multigrade.
Classic Engine Oils - Classic Car Oil Products | Castrol United Kingdom | Classic Oils - Car | Motor Oil & Lubricants | Castrol United Kingdom | Car - Motor Oil & Lubricants | Castrol United Kingdom | Products | Castrol United Kingdom | Castrol - Eng
Heres a graphic over oil quality, viscosity and additives (multigrade). Pretty nifty
https://socratic.org/questions/what-is-the-difference-between-monograde-and-multigrade-oil
I tried to find some graphs I have. Perhaps a copywrite issue if I did. What they show is a well sorted out idler drive looks more like a Revox style tape deck when tested. Better still the test can be repeated with the test disc moved around. Sometimes the test disc and turntable null or add. At this point sometimes it is the test disc that is being measured more than the turntable. 60/33.33 will be very well engineered by Thorens. My guess is it will be 10 % of the measured result of a typical TD124. The rest will be idler, belt, bearings and oil. One way to detect the wrong oil is listen to the motor with the platter off. If it is silent with new oil and not so a month later replace the oil. If it is transformed the chances are it's the wrong oil. The wrong one has a higher frequency rubbing sound. Very subtle and not realised unless pointed out. Esso insisted a monograde best. SAE20 or 30 depending on which works best. 30 seems fine.
One thing to know about belt drives. They were invented to reduce the cost of making a turntable. If a Linn LP12 is made to vibrate badly by wrong motor phase capacitor it is surprising how good the sound is. The belt absorbs most of it and the suspension a large amount. If the motor voltage is changed between 60 and 100 Vrms it is a different story. The LP12 or TD160 can have the platter inverted to see what is happening. With the LP12 and wrong phase cap ( 100 nF not 220 nF for example ) the belt actually seems to flap about 2 mm. The question is. If it deals with motor vibration so well what about the disc modulations. It is a two way street. AR is said to have invented belt drive. As we know it, yes. Philips had a design in the early 1950's with a tension wheel like if a cambelt. That would start to address the problem. Verdier mentioned it in his design. He thought some uniform drag to be ideal. If I understood correctly he hoped the drag of the oil ( or magnetic brake ) would be 10 times that of the stylus.
One thing to know about belt drives. They were invented to reduce the cost of making a turntable. If a Linn LP12 is made to vibrate badly by wrong motor phase capacitor it is surprising how good the sound is. The belt absorbs most of it and the suspension a large amount. If the motor voltage is changed between 60 and 100 Vrms it is a different story. The LP12 or TD160 can have the platter inverted to see what is happening. With the LP12 and wrong phase cap ( 100 nF not 220 nF for example ) the belt actually seems to flap about 2 mm. The question is. If it deals with motor vibration so well what about the disc modulations. It is a two way street. AR is said to have invented belt drive. As we know it, yes. Philips had a design in the early 1950's with a tension wheel like if a cambelt. That would start to address the problem. Verdier mentioned it in his design. He thought some uniform drag to be ideal. If I understood correctly he hoped the drag of the oil ( or magnetic brake ) would be 10 times that of the stylus.
new td124 subject: switches and that neon bulb holder
In recent months I have serviced 4 different td124 units, and each of them presented a unique mix of problems to be solved. But it is the last one that I want to post about today.
The subject is my own td124 serial number 13943. E50 equipped. It has a new coil set from AudioSilente. The motor has received the customary CLA (clean, lube, adjust) and its rotor exhibits very long spin down times while not powered.
The problem was when I put power to it (115 vac @ 60 hz) that the motor exhibited low torque.....not enough to turn the platter.
In trouble shoot mode I first checked to see that the coils were getting adequate voltage. (At the voltage commutator.) I did this with a multi-meter while placing a probe at the red solder tab and the other probe at a black. (both red and black to the same coil) and with power on I read 56 vac. Not enough. I should be seeing full 115 volts. (Btw. Be careful when doing this as accidental electrocution may occur)
Btw, I checked voltage at the mains and did measure 115 vac.
Thinking that the stator coil set should be ok (better than stock) I proceded to search for what was preventing full voltage from getting from the mains to my stator coils. I started with the on/off switch.
To check the switch it occurred to me that what I wanted to know was if the switch, in addition to interrupting the flow of current, was acting like a resistor and not allowing 'all' of the current flow to pass through it. Using the multi-meter again I checked across the switch for ohms. In the past I have measure .1 ohms on switches that were part of a healthy motor circuit. This one was measuring .6 ohms. So I disassembled the switch and cleaned all of the metal parts with acetone. The contact breaker was clean and free of sparking residue, but I washed that with acetone also. Reassembled the switch and conducted the ohms test again. This time I read .1 ohms. Good. That eliminates the switch
But the motor still was not getting 115 into its coils when resting the red and black solder tabs on the commutator. Still 56 vac.
Oh, btw, the neon strobe bulb had been lighting up with apparent strength through out.....and still was. And I had renewed the 33kohms resistor, which measured 33 kohms on the multi-meter.
next, I had to consider if the bulb holder, or the wires themselves were acting as a resistor.
The wires checked ok and looked good. But the bulb holder had an issue I had previously passed over; Of the two spring pins inside that create the circuit to the bulb, one of them had a crunchy action. I could realize this while pressing down on the pin with the eraser end of a wood pencil. Crunchy crunchy. Hmmm. There must be some history there, I thught to myself.
I ohms tested the bulb holder by inserting one multi-meter probe into the hole of the wire clamp and lightly screwed the set screw down to hold that probe in place . Then did same with the second post and probe. With the multi-meter set to measure ohms I placed a flat bladed screw drive across the two pins within the holder to create a short and get an ohms reading. The read was .5 ohms. Hmmmm. Add this to the crunch action of the one pin and it occurred to me that perhaps a little cleaning with acetone might be useful in improving this ohms read.
So I used a modelers paint brush and some clean acetone to dribble some acetone down into the bore and spring of the spring pin. I did this repeatedly while alternately pushing on the pin to work the acetone into the parts within.
You know these bulb holders are not built to be disassembled. The only way to take one apart is to destroy it. Hence my method.
Anyway I continued the acetone with lots of spring pushing to see if I could not clean the conducting surfaces within and get rid of the resistancee I was measuring.
As final touch I dribbled about 3 small globules of light silicone lube into the the pin and worked the action some more with my pencil erasor.
Then, finally, the test...... Multi-meter hooked up as before. This time the reading was .1 ohms. Wow. That's better, let's try it, I said.
Skipping the voltage test at the commutator, I just assembled the wires to the holder and the bulb into it. Assembled the strobe into the chassis as per design and ran the motor.
Guess what....? The motor now had much more torque.! Problem solved?
Well It's running strong now. On a summer morning cool start up I have 33-1/3rd on the strobe within the first rev!
After that, some pitch adjust while all of its drive train parts get up to operating temp...
For future reference my take is to test voltage going into the coil just to see that a switch, a bulb holder, or even a wire isn't acting like a resistor.
-Steve
In recent months I have serviced 4 different td124 units, and each of them presented a unique mix of problems to be solved. But it is the last one that I want to post about today.
The subject is my own td124 serial number 13943. E50 equipped. It has a new coil set from AudioSilente. The motor has received the customary CLA (clean, lube, adjust) and its rotor exhibits very long spin down times while not powered.
The problem was when I put power to it (115 vac @ 60 hz) that the motor exhibited low torque.....not enough to turn the platter.
In trouble shoot mode I first checked to see that the coils were getting adequate voltage. (At the voltage commutator.) I did this with a multi-meter while placing a probe at the red solder tab and the other probe at a black. (both red and black to the same coil) and with power on I read 56 vac. Not enough. I should be seeing full 115 volts. (Btw. Be careful when doing this as accidental electrocution may occur
)Btw, I checked voltage at the mains and did measure 115 vac.
Thinking that the stator coil set should be ok (better than stock) I proceded to search for what was preventing full voltage from getting from the mains to my stator coils. I started with the on/off switch.
To check the switch it occurred to me that what I wanted to know was if the switch, in addition to interrupting the flow of current, was acting like a resistor and not allowing 'all' of the current flow to pass through it. Using the multi-meter again I checked across the switch for ohms. In the past I have measure .1 ohms on switches that were part of a healthy motor circuit. This one was measuring .6 ohms. So I disassembled the switch and cleaned all of the metal parts with acetone. The contact breaker was clean and free of sparking residue, but I washed that with acetone also. Reassembled the switch and conducted the ohms test again. This time I read .1 ohms. Good. That eliminates the switch
But the motor still was not getting 115 into its coils when resting the red and black solder tabs on the commutator. Still 56 vac.
Oh, btw, the neon strobe bulb had been lighting up with apparent strength through out.....and still was. And I had renewed the 33kohms resistor, which measured 33 kohms on the multi-meter.
next, I had to consider if the bulb holder, or the wires themselves were acting as a resistor.
The wires checked ok and looked good. But the bulb holder had an issue I had previously passed over; Of the two spring pins inside that create the circuit to the bulb, one of them had a crunchy action. I could realize this while pressing down on the pin with the eraser end of a wood pencil. Crunchy crunchy. Hmmm. There must be some history there, I thught to myself.
I ohms tested the bulb holder by inserting one multi-meter probe into the hole of the wire clamp and lightly screwed the set screw down to hold that probe in place . Then did same with the second post and probe. With the multi-meter set to measure ohms I placed a flat bladed screw drive across the two pins within the holder to create a short and get an ohms reading. The read was .5 ohms. Hmmmm. Add this to the crunch action of the one pin and it occurred to me that perhaps a little cleaning with acetone might be useful in improving this ohms read.
So I used a modelers paint brush and some clean acetone to dribble some acetone down into the bore and spring of the spring pin. I did this repeatedly while alternately pushing on the pin to work the acetone into the parts within.
You know these bulb holders are not built to be disassembled. The only way to take one apart is to destroy it. Hence my method.
Anyway I continued the acetone with lots of spring pushing to see if I could not clean the conducting surfaces within and get rid of the resistancee I was measuring.
As final touch I dribbled about 3 small globules of light silicone lube into the the pin and worked the action some more with my pencil erasor.
Then, finally, the test...... Multi-meter hooked up as before. This time the reading was .1 ohms. Wow. That's better, let's try it, I said.
Skipping the voltage test at the commutator, I just assembled the wires to the holder and the bulb into it. Assembled the strobe into the chassis as per design and ran the motor.
Guess what....? The motor now had much more torque.! Problem solved?
Well It's running strong now. On a summer morning cool start up I have 33-1/3rd on the strobe within the first rev!
After that, some pitch adjust while all of its drive train parts get up to operating temp...
For future reference my take is to test voltage going into the coil just to see that a switch, a bulb holder, or even a wire isn't acting like a resistor.
-Steve
Last edited:
Thanks for the info Steve. As the lamp is only in series with the 33k resistor I can only assume there must be two wires joined inside the lampholder. (I haven't taken my 124/II apart to check this). If this is the case and it's not possible to dismantle the lampholder it might be easier to simply join the two wires outside of the holder, and then not worry too much about what happens inside the holder. After all there's a 33k resistor on the other side so a few extra ohms aren't going to hurt the illumination of the bulb.
It is always interesting to visit the thread and see nice people with passion and perfectionism for that very very musical and involving sounding tt. I am in audio about 40 years and I had owned many good tts.No tt is compared with 124. I had used Dual 1019 idler wheel when I was very young, next an Era, after that the Ariston RD11,several Linn versions, Pink Triangle, Walker, Benz Revox , Kuzma Stabi, Micro Seiki BL 91, Thorens 150, 125, 126,EMT 928 , Aura from David Whitaker and my last was the Transrotor Apollo. All could not be compared to the musicality , PRAT, dynamics, emotional touch, liveness etc of the 124...that is and will be my last and best tt.
I will need to replace its bubble lever as it seems empty...How can I remove it without to cause any damage to its housing that is part of the chassis.. I think that if I could soften the glue that holds it by using alcohol or ?.. then it might be easier to remove it by pressing it?
If not thatsmoother way, have I to push it strong from out side to inside using a.. hammer?
I will need to replace its bubble lever as it seems empty...How can I remove it without to cause any damage to its housing that is part of the chassis.. I think that if I could soften the glue that holds it by using alcohol or ?.. then it might be easier to remove it by pressing it?
If not that
smoother way, have I to push it strong from out side to inside using a.. hammer?
Last edited:
I don't know what type of adhesive was used to affix the bubble level, but it was probably some form of contact adhesive. I'm in a similar position to yourself, though my level hasn't lost its fluid I do want to replace it with one that hasn't yellowed. I'm going to try using a hair dryer on the underside of the casting, in the hope that it will soften the adhesive enough for me to be able to lever the level out with a screwdriver, using a popsicle stick to lever on and avoid damaging the surface.