Hi all.
Searched for this issue, found nothing but forgive me if it's well known...
My Pro-Ject Debut Carbon DC (maybe 3 years-old) motor will often make a kind of 'toc toc toc toc...' fairly loud noise when started 'cold' (i.e. room temperature after being off for several hours/days). Seems noise has same frequency as motor rotation, once per turn I believe. Belt on or off, no difference. Moving motor on its suspension has no effect.
Curious thing is that after 10-20 minutes, the noise disappears and deck operates silently for as long as it is on afterwards.
Only mods are acrylic platter and Ortofon 2M Blue stylus in 2M Red cartridge, so nothing relevant here.
Anybody else? Does motor lubrication falls to bottom of motor and needs to be re-spread by heat? Cheers!
--Christian
Searched for this issue, found nothing but forgive me if it's well known...
My Pro-Ject Debut Carbon DC (maybe 3 years-old) motor will often make a kind of 'toc toc toc toc...' fairly loud noise when started 'cold' (i.e. room temperature after being off for several hours/days). Seems noise has same frequency as motor rotation, once per turn I believe. Belt on or off, no difference. Moving motor on its suspension has no effect.
Curious thing is that after 10-20 minutes, the noise disappears and deck operates silently for as long as it is on afterwards.
Only mods are acrylic platter and Ortofon 2M Blue stylus in 2M Red cartridge, so nothing relevant here.
Anybody else? Does motor lubrication falls to bottom of motor and needs to be re-spread by heat? Cheers!
--Christian
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Nigelwright7557 could be right but please be aware several websites comment on "motor hum/vibration " .
While not all owners had this complaint a significant number did, all were related to the motor this was even after the new power supply was installed.
The ones affected couldn't reach or get a precise cause even after changing the sound absorption.
This is directly related to motor design/cost and I can understand that absorption material is cheaper than a very high quality motor.
This is presupposing the actual power supply is beyond reproach even after an upgrade ?
There has long been arguments in the hi-fi media as to the pros and cons of ac/dc motors including very expensive power supplies, this went on for years .
The "winner" being an expensive industrial standard ac multi-pole motor but even there arguments raged on .
For the record I replaced the aged absorption on the base of my old Dais record deck with top quality material as a matter of coarse but there again I don't have any hum/noise from it.
As decks become lighter in surrounding fixtures this sort of thing will crop up again and again due to easier mechanical transmission of vibration.
While not all owners had this complaint a significant number did, all were related to the motor this was even after the new power supply was installed.
The ones affected couldn't reach or get a precise cause even after changing the sound absorption.
This is directly related to motor design/cost and I can understand that absorption material is cheaper than a very high quality motor.
This is presupposing the actual power supply is beyond reproach even after an upgrade ?
There has long been arguments in the hi-fi media as to the pros and cons of ac/dc motors including very expensive power supplies, this went on for years .
The "winner" being an expensive industrial standard ac multi-pole motor but even there arguments raged on .
For the record I replaced the aged absorption on the base of my old Dais record deck with top quality material as a matter of coarse but there again I don't have any hum/noise from it.
As decks become lighter in surrounding fixtures this sort of thing will crop up again and again due to easier mechanical transmission of vibration.
If its a dry plain metal bearing then two surfaces can rub and resonate.
If its a ball bearing then the balls cam rub against the ball cage if no lubricant and resonate.
If its a ball bearing then the balls cam rub against the ball cage if no lubricant and resonate.
A regular sound like that usually means something is hitting something - there's a machanical problem that should be investigated. It might have debris inside it, a loose
winding, or many other possibilities.
The type of bearing will determine the type of lubricant needed - grease is not a panacea, and is completely wrong for phosphor-bronze bearings for instance.
winding, or many other possibilities.
The type of bearing will determine the type of lubricant needed - grease is not a panacea, and is completely wrong for phosphor-bronze bearings for instance.
A good point Mark ,my own platter bearing uses a high quality light oil required occasionally over the years .
This has helped keep it in good condition.
My actual motor is completely sealed and as an ex.engineer I am happy I use a British made deck the business being originally in Nottingham and,at the time, the designer was very helpful when contacted on the phone.
This has helped keep it in good condition.
My actual motor is completely sealed and as an ex.engineer I am happy I use a British made deck the business being originally in Nottingham and,at the time, the designer was very helpful when contacted on the phone.
Hello all.
Thank you for your suggestions. First let me reiterate what the 'problem' is before we move too far in the wrong direction... It looks like no one else observed the same thing perhaps?
1. The relevant parts (motor and wall-wart supply) are completely stock. The turntable is not modified in any way apart from the acrylic platter and the stylus. No power supply 'upgrade' or modification has ever been done.
2. The noise is not hum nor vibration, but a 'toc toc toc...' that seems to be synchronized with the motor revolutions and coming from inside the motor. It could be called a mechanical noise. The noise is not related to the belt or platter bearing, as it can be heard when belt is removed and platter immobile.
If the motor is indeed a ball bearing one, a ball encountering an imperfection in the bearing race could very well be the cause. Several minutes of operation could redistribute the lubricant inside the bearing and silence it, as observed.
If that is the case, I would likely just live with the situation rather than disassemble the motor. If it gets worse, I would contemplate dropping a small quantity of light oil in the motor bearings.
Thanks again!
--Christian
Thank you for your suggestions. First let me reiterate what the 'problem' is before we move too far in the wrong direction... It looks like no one else observed the same thing perhaps?
1. The relevant parts (motor and wall-wart supply) are completely stock. The turntable is not modified in any way apart from the acrylic platter and the stylus. No power supply 'upgrade' or modification has ever been done.
2. The noise is not hum nor vibration, but a 'toc toc toc...' that seems to be synchronized with the motor revolutions and coming from inside the motor. It could be called a mechanical noise. The noise is not related to the belt or platter bearing, as it can be heard when belt is removed and platter immobile.
If the motor is indeed a ball bearing one, a ball encountering an imperfection in the bearing race could very well be the cause. Several minutes of operation could redistribute the lubricant inside the bearing and silence it, as observed.
If that is the case, I would likely just live with the situation rather than disassemble the motor. If it gets worse, I would contemplate dropping a small quantity of light oil in the motor bearings.
Thanks again!
--Christian
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Mark is quite right ,having repaired electric motors you could have the following-
1- a foreign body is jammed between the stator and rotor .
2-part of the rotor has come loose.
3-as has been said there is wear in the bearing of both types --if the wear has already taken place no amount of oil will permanently fix it ,just delay it.
Do you feel any play when trying to move the pulley attached to the motor shaft ?
If not its likely as Mark says .
I don't know why you are worried about disassembling an electric motor , I have stripped down all types of factory equipment (machine tools ) of all shapes and sizes ,its not magic just practical electrical engineering logic.
1- a foreign body is jammed between the stator and rotor .
2-part of the rotor has come loose.
3-as has been said there is wear in the bearing of both types --if the wear has already taken place no amount of oil will permanently fix it ,just delay it.
Do you feel any play when trying to move the pulley attached to the motor shaft ?
If not its likely as Mark says .
I don't know why you are worried about disassembling an electric motor , I have stripped down all types of factory equipment (machine tools ) of all shapes and sizes ,its not magic just practical electrical engineering logic.
Hi Duncan.
Thanks four your reply. Yes I had considered Mark T's reply, perhaps in a roundabout way:
"If the motor is indeed a ball bearing one, a ball encountering an imperfection in the bearing race could very well be the cause."
I am not weary of disassembling the motor, just thought I'd only do it if problem got worse. But since noise disappears after a few minutes every time (AFAIK), I thought I'd leave it like this.
But you are right, if there is a foreign body, this might spell disaster in the long run. There is no play in the motor right now. I will take it apart and re-pack (as bicycle mechanics would say...).
I am a bit surprised because my old Thorens TD-147's nearly 35 years old motor (year unknown, bought used) was silent (I lent it long term to a friend, too bad for me, good for him). The Pro-Ject, in comparison, only has less than 1/10th use! Cheers.
--Christian
Thanks four your reply. Yes I had considered Mark T's reply, perhaps in a roundabout way:
"If the motor is indeed a ball bearing one, a ball encountering an imperfection in the bearing race could very well be the cause."
I am not weary of disassembling the motor, just thought I'd only do it if problem got worse. But since noise disappears after a few minutes every time (AFAIK), I thought I'd leave it like this.
But you are right, if there is a foreign body, this might spell disaster in the long run. There is no play in the motor right now. I will take it apart and re-pack (as bicycle mechanics would say...).
I am a bit surprised because my old Thorens TD-147's nearly 35 years old motor (year unknown, bought used) was silent (I lent it long term to a friend, too bad for me, good for him). The Pro-Ject, in comparison, only has less than 1/10th use! Cheers.
--Christian
Does anybody know how to prevent the forum editor from inserting extra <CR>s when the Enter key is pressed?
--Christian
--Christian
Your friend was lucky Christiang thats a good deck you gave him I have it on one of my Hi-Fi Choice record deck review books --16 pole synchronous motor which is reliable .
Your Project deck according to the company is Czech (according to one of their websites ) and hand-built there and looks a quality product .
According to their Australian advertising and website its headquarters are in Austria .
I was trying to find if the motor is made there too and not a Chinese import like many HI-Fi equipment makers fail to mention .
The wiki on them is in dispute just now.
With the knowledge I have gained over the years in detective work in tracing company origins and supply I would need verification that the motor is also made in a Czech factory.
Overall it looks a good deck at the price at 2020 values although I think a lot of quality decks made in the 1970,s / 1980,s you got a very high degree on mechanical engineering in some of those old decks and the better ones were made in European countries not China although some Japanese types were also pretty good .
Your Project deck according to the company is Czech (according to one of their websites ) and hand-built there and looks a quality product .
According to their Australian advertising and website its headquarters are in Austria .
I was trying to find if the motor is made there too and not a Chinese import like many HI-Fi equipment makers fail to mention .
The wiki on them is in dispute just now.
With the knowledge I have gained over the years in detective work in tracing company origins and supply I would need verification that the motor is also made in a Czech factory.
Overall it looks a good deck at the price at 2020 values although I think a lot of quality decks made in the 1970,s / 1980,s you got a very high degree on mechanical engineering in some of those old decks and the better ones were made in European countries not China although some Japanese types were also pretty good .