Hi Deano,
Do you know the size of your subplatter? Or does the belt run around the platter's periphery? The exact motor speed will be simple to calculate with this one additional piece of information.
The Linn uses the same pulley in their DC drive as they do with the AC. The motor speed here is 250rpm.
The granddaddy of modern turntable DC motors is Pink Triangle. They run their motor at about 300rpm. The motor used by Pink is a premotec with a Tacho.
Niffy
Do you know the size of your subplatter? Or does the belt run around the platter's periphery? The exact motor speed will be simple to calculate with this one additional piece of information.
The Linn uses the same pulley in their DC drive as they do with the AC. The motor speed here is 250rpm.
The granddaddy of modern turntable DC motors is Pink Triangle. They run their motor at about 300rpm. The motor used by Pink is a premotec with a Tacho.
Niffy
Here is an interesting comparison of various motors for turntable use. Apart from the AC motors mentioned (primarily for idler-wheel applications, such as Garrards and Lencos), there are also other DC motors from Premotec and Maxon. https://electravolt.blogspot.com/search/label/Idler wheel turntable
It may provide some insights on the topic we are discussing, especially with respect to motor vibrations and sound quality.
It may provide some insights on the topic we are discussing, especially with respect to motor vibrations and sound quality.
I have a LP12. Not home now to measure but guess it’s around 180mm.
Maxon sold me a Radikal 1 motor. I will install that at some point and will use a bigger pulley maybe 20mm like Linn use. Slower is probably good for low vibration.
Hi, you need to get the coltage to the mootor up to around 3.5 VDC. At 1.5 V it is to near the stall voltage. So it would seem that running RPM is to high for a rim drive T/T. My motor runs at 3500 RPM, and at 3.5 V I get my 33.3 RPM speed.
Cheers
Cheers
Hi Panos,
Very interesting article.
The Maxon I have on order, 226764 has 25.6mNm of torque compared with the 8.62mNm of the 226774 reviewed in the article. Very similar to the DCX 22, which has around 22mNm. Hopefully it will result in a similar performance boost.
Unfortunately Maxon had, for some undisclosed reason, not actually dispatched my motor when they said they would. Apparently they are going to post it today but I'm not going to hold my breath. Hopefully I'll be able to report on how it compares to my premotec soon.
Niffy
Very interesting article.
The Maxon I have on order, 226764 has 25.6mNm of torque compared with the 8.62mNm of the 226774 reviewed in the article. Very similar to the DCX 22, which has around 22mNm. Hopefully it will result in a similar performance boost.
Unfortunately Maxon had, for some undisclosed reason, not actually dispatched my motor when they said they would. Apparently they are going to post it today but I'm not going to hold my breath. Hopefully I'll be able to report on how it compares to my premotec soon.
Niffy
Hi Niffy,
I am glad you liked the article. I've also found it quite enlightening.
I am curious about your impressions, when you receive the Maxon motor. May I ask how much it cost?
Thanks,
Panos
I am glad you liked the article. I've also found it quite enlightening.
I am curious about your impressions, when you receive the Maxon motor. May I ask how much it cost?
Thanks,
Panos
Hi Panos,
The total cost of the motor including carriage was £240. Unfortunately Maxon carriage costs are rather exorbitant at over £60.
I'm just keeping my fingers crossed that I don't get stung with import duty (one of the many joys of brexit).
I have received notification that it has now been shipped.
Niffy
The total cost of the motor including carriage was £240. Unfortunately Maxon carriage costs are rather exorbitant at over £60.
I'm just keeping my fingers crossed that I don't get stung with import duty (one of the many joys of brexit).
I have received notification that it has now been shipped.
Niffy
Hi Niffy,
I know, I know about Brexit. Having studied in the UK (Cranfield University), I cannot understand how the UK is not part of the EU anymore. A bad decision for both parties in my opinion. I know that the EU has several deficiencies, but keeping European countries united is the only way to be viable and competitive against the rest of the world.
Thanks for the heads up about the motor price. I hope you do not have to pay any import duties (where is it coming from? Switzerland?) and that you will be able to enjoy the new motor after all. You said it's 36V, right?
Cheers,
P.
I know, I know about Brexit. Having studied in the UK (Cranfield University), I cannot understand how the UK is not part of the EU anymore. A bad decision for both parties in my opinion. I know that the EU has several deficiencies, but keeping European countries united is the only way to be viable and competitive against the rest of the world.
Thanks for the heads up about the motor price. I hope you do not have to pay any import duties (where is it coming from? Switzerland?) and that you will be able to enjoy the new motor after all. You said it's 36V, right?
Cheers,
P.
Hi Panos,
Brexit surely was a very bad move. You'll notice that the flag next to my name is the European Union flag. I changed it to show that I am European and definitely not a brexiteer.
The new motor is 48v.
Niffy
Brexit surely was a very bad move. You'll notice that the flag next to my name is the European Union flag. I changed it to show that I am European and definitely not a brexiteer.
The new motor is 48v.
Niffy
Nice unit, however from what I understand has bearings for the to[ end, which will be noisier. so I should plan to use an out-board motor pod to keep the noise from entering your plinth, easy to do. Also use a Mylar belt to drive the platter, which again is simple to make up, gives stunningly superior results over thread & flat rubber belts.
Cheers
Cheers
Attachments
Hi DNic,
When you say that your motor runs at 3500rpm is this the rated speed of the motor or the speed you are running to obtain 33 1/3rpm? 3500 seems rather fast as it equates to nearly 60hz, well into the audio band. From your photo (beautiful deck) l would have estimated a motor speed closer to 1500rpm, which still seems a bit fast.
I'm aiming for a much lower motor speed of 300rpm and have selected a model with a speed constant to run at 5v so will be well above stalling and should be very stable.
Which motor were you referring to your last post? Is it the Re-Max I have on order? I selected a model with sintered bearings as these will be quieter than ball bearings. What was the issue with the bearing.
Niffy
When you say that your motor runs at 3500rpm is this the rated speed of the motor or the speed you are running to obtain 33 1/3rpm? 3500 seems rather fast as it equates to nearly 60hz, well into the audio band. From your photo (beautiful deck) l would have estimated a motor speed closer to 1500rpm, which still seems a bit fast.
I'm aiming for a much lower motor speed of 300rpm and have selected a model with a speed constant to run at 5v so will be well above stalling and should be very stable.
Which motor were you referring to your last post? Is it the Re-Max I have on order? I selected a model with sintered bearings as these will be quieter than ball bearings. What was the issue with the bearing.
Niffy
Hi, No I mean 3500 rpm is about the highest rated speed motor you can use to achieve 33RPM at around 3.5 VDC on a T/T driving the outer platter.
I must admit I do not actually know what my motor is running at when the platter is at 33 RMP.
I am using a Portescap 26N 5821EE !
Also if you cannot make a Mylar belt you can buy one from Galibrier T/T's for about $35.
Did not realise you had selected a sintered top bearing, yes they are quieter than a ball race but do not last as long. I read somewhere Maxon advising that sintered bearing used for a T/T the sintered bearing
would last around a year. That of course depends on how many LP's you spin.
Cheers
I must admit I do not actually know what my motor is running at when the platter is at 33 RMP.
I am using a Portescap 26N 5821EE !
Also if you cannot make a Mylar belt you can buy one from Galibrier T/T's for about $35.
Did not realise you had selected a sintered top bearing, yes they are quieter than a ball race but do not last as long. I read somewhere Maxon advising that sintered bearing used for a T/T the sintered bearing
would last around a year. That of course depends on how many LP's you spin.
Cheers
Hi DNic,
I couldn't find any information about your Portescap motor.
Odd thing about Maxon saying that sintered bearings would only last a year. The Premotec I'm currently using has, I believe, sintered bearings and it have been in constant use for around 10yrs. It has actually gotten quieter over the years. I think that the motors used by Linn also use sintered bearings but I'm not certain.
My deck has a pretty unique drive and bearing configuration that uses three round belts. Unfortunately mylar would not work on my deck. I am using a nitrile rubber that is very low stretch.
This is with the Origin Live pulley still fitted.
I couldn't find any information about your Portescap motor.
Odd thing about Maxon saying that sintered bearings would only last a year. The Premotec I'm currently using has, I believe, sintered bearings and it have been in constant use for around 10yrs. It has actually gotten quieter over the years. I think that the motors used by Linn also use sintered bearings but I'm not certain.
My deck has a pretty unique drive and bearing configuration that uses three round belts. Unfortunately mylar would not work on my deck. I am using a nitrile rubber that is very low stretch.
This is with the Origin Live pulley still fitted.
Hi Niffy,
this is indeed a quite original, unique bearing and drive type. Would be kind enough to post more pictures? It seems that you have a rather long belt (o-ring type), going around a 2-3 times around the subplatter. It appears to ensure good friction with the platter, but I wonder whether it requires a stronger motor than the ones used in simpler belt-drives.
In any case, still very interested in your impressions, as soon as your new Maxon motor arrives. It should be in your hands any day now, right?
With respect to the longevity of sintered sleeve bearings, I would be surprised if any motor lasted just one year (in the context of regular turntable use). It sounds rather unrealistic, as such a short expected life would render the motor undesirable for any application.
this is indeed a quite original, unique bearing and drive type. Would be kind enough to post more pictures? It seems that you have a rather long belt (o-ring type), going around a 2-3 times around the subplatter. It appears to ensure good friction with the platter, but I wonder whether it requires a stronger motor than the ones used in simpler belt-drives.
In any case, still very interested in your impressions, as soon as your new Maxon motor arrives. It should be in your hands any day now, right?
With respect to the longevity of sintered sleeve bearings, I would be surprised if any motor lasted just one year (in the context of regular turntable use). It sounds rather unrealistic, as such a short expected life would render the motor undesirable for any application.
Hi Panos,
I'm actually a proponent of short low-stretch belts.
I have three short belts, one motor and two idler wheels.
One belt goes around the motor and the sub-platter in a conventional way. The other two belts each go around an idler wheel and the sub-platter. The tension of the individual belts balance the side forces on the main bearing, which is inverted. It does this to such an extent that it completely eliminates these side forces. As there are no side forces acting on the bearing sleeve it is no longer required and has been eliminated from the design. I have what is in essence a unipivot main bearing.
In a typical conventional sleeved bearing over 95% of frictional torque is due to the sleeve. Likewise the vast majority of variation in torque is due to the sleeve. With my design the load is significantly reduced. My main bearing dissipates less than 2 milliwatts. Many bearings are dissipating well over 200 mW. This will heat the bearing causing it to change its performance as it warms and cools. The friction and noise of the idler bearings are much lower than that of the sleeve and, like the motor, are isolated from the platter by the belts. By using three separate belts, rather than a single that goes around both idlers and motor, runout of the platter is almost entirely eliminated. In combination with my clamping system the amount of vertical movement of the cartridge is lower than that seen with most decks.
I don't think that the main advantage of my bearing system is the reduction in bearing friction, reduction in variation of friction and reduction of bearing noise. These are very low anyway with most well engineered bearings, though further reduction is still a good thing.
I think the main advantage is in the way the bearing constrains the platter. The best analogy I have is the Chladni plate. When unconstrained the sand forms the simplest pattern. As soon as any constraint is applied the pattern becomes more complex. With a platter the sleeve of the bearing acts as a constraint.
The best way I can describe it sonically is that removing the sleeve seems to open the sound up giving a greater sense of space and transparency.
Niffy
I'm actually a proponent of short low-stretch belts.
I have three short belts, one motor and two idler wheels.
One belt goes around the motor and the sub-platter in a conventional way. The other two belts each go around an idler wheel and the sub-platter. The tension of the individual belts balance the side forces on the main bearing, which is inverted. It does this to such an extent that it completely eliminates these side forces. As there are no side forces acting on the bearing sleeve it is no longer required and has been eliminated from the design. I have what is in essence a unipivot main bearing.
In a typical conventional sleeved bearing over 95% of frictional torque is due to the sleeve. Likewise the vast majority of variation in torque is due to the sleeve. With my design the load is significantly reduced. My main bearing dissipates less than 2 milliwatts. Many bearings are dissipating well over 200 mW. This will heat the bearing causing it to change its performance as it warms and cools. The friction and noise of the idler bearings are much lower than that of the sleeve and, like the motor, are isolated from the platter by the belts. By using three separate belts, rather than a single that goes around both idlers and motor, runout of the platter is almost entirely eliminated. In combination with my clamping system the amount of vertical movement of the cartridge is lower than that seen with most decks.
I don't think that the main advantage of my bearing system is the reduction in bearing friction, reduction in variation of friction and reduction of bearing noise. These are very low anyway with most well engineered bearings, though further reduction is still a good thing.
I think the main advantage is in the way the bearing constrains the platter. The best analogy I have is the Chladni plate. When unconstrained the sand forms the simplest pattern. As soon as any constraint is applied the pattern becomes more complex. With a platter the sleeve of the bearing acts as a constraint.
The best way I can describe it sonically is that removing the sleeve seems to open the sound up giving a greater sense of space and transparency.
Niffy
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That's quite interesting, Niffy.
Would you be so kind to upload a short video showing the rotation of the platter, so that we get a better understanding of the belt and idler motion? That would be quite enlightening.
Thanks.
Would you be so kind to upload a short video showing the rotation of the platter, so that we get a better understanding of the belt and idler motion? That would be quite enlightening.
Thanks.
Hi, VERY, very nice design. As they say there are many more ways to ''skin a cat'' Do you know what rotational speed the Maxon will rotate at for the arrangement. Does the small dia sub platter take more torque to start up, than from Rim drive.
My Portescap motor is currently used by an English firm (sorry can't remember the name) who do several quite sophisticated motor & controller upgrades.
Cheers
My Portescap motor is currently used by an English firm (sorry can't remember the name) who do several quite sophisticated motor & controller upgrades.
Cheers
Hi DNic,
The motor will be rotating at around 300rpm.
The small sub-platter will take the same motor torque to start up as it would for a rim drive IF the pulleys for both are selected to give the same motor speed.
I use a screw down clamp. I always spin the platter up manually using the clamp. This will help extend the life of the belt by reducing stretch and prevent belt slippage which can wear the surface of the belt and cause deposits to build up on the pulley.
The damaged Maxon span the record up to speed in less than half the time of the Premotec when I checked this.
Niffy
The motor will be rotating at around 300rpm.
The small sub-platter will take the same motor torque to start up as it would for a rim drive IF the pulleys for both are selected to give the same motor speed.
I use a screw down clamp. I always spin the platter up manually using the clamp. This will help extend the life of the belt by reducing stretch and prevent belt slippage which can wear the surface of the belt and cause deposits to build up on the pulley.
The damaged Maxon span the record up to speed in less than half the time of the Premotec when I checked this.
Niffy
Hi diyAudio members, new Canadian member here attracted by the friendly and knowledgeable posts contributed on different projects
Relative to this thread I too possess a Roksan Xerxes which requires a new motor and controller, so thank you Panos, niffy, deano and Dnic
While unable to contribute much to technical discussions my "cure" for Roksan plinth sag was to select an appropriate sized brass posidrive headed wood screw, realign the plinth sections, and gently wind the screw into the slot from underneath, thereby restoring section alignment
Despite presumably altering the plinth's dampening characteristics my (younger) ears detected no material difference in sound quality via Shure V15-5MR cartridge, Alphason HR100-MCS tone arm, and bi wired Spica TC-50 speakers
David B
Relative to this thread I too possess a Roksan Xerxes which requires a new motor and controller, so thank you Panos, niffy, deano and Dnic
While unable to contribute much to technical discussions my "cure" for Roksan plinth sag was to select an appropriate sized brass posidrive headed wood screw, realign the plinth sections, and gently wind the screw into the slot from underneath, thereby restoring section alignment
Despite presumably altering the plinth's dampening characteristics my (younger) ears detected no material difference in sound quality via Shure V15-5MR cartridge, Alphason HR100-MCS tone arm, and bi wired Spica TC-50 speakers
David B