The circuit made by pyramid is crystal locked and doesn't drift.
So basically the DC motor would also have less torque as I suspected (didn't mention it because I wasn't sure about it!)
Where can I find Arthur design? Is it the one you linked before? The K system was over $800 which is still reasonable though.
What is, in your opinion, the best DC motor?
If Noise doesn't become a concern, then having an external pad with 3 of them to overcome stylus drag, would be a piece of pie in terms of vibration.
So basically the DC motor would also have less torque as I suspected (didn't mention it because I wasn't sure about it!)
Where can I find Arthur design? Is it the one you linked before? The K system was over $800 which is still reasonable though.
What is, in your opinion, the best DC motor?
If Noise doesn't become a concern, then having an external pad with 3 of them to overcome stylus drag, would be a piece of pie in terms of vibration.
I have been trying to contact him all morning but only voice mail.....is he in business at all or does he do that part time?
It is very unlikely anyone on this thread considers driving AC motors directly from the mains. It is easy enough to build or buy a bi-phase adjustable controller. It is a bit more complicated if the motor runs at 115v but certainly doable.
DC motor driven turntables do sound different and at the end it is a matter of sonic preference.
As regards to absolute speed stability of dc motors i don't seem to find this a problem. Tried briefly a negative output impedance controller and while speed stability was great i still preferred the sound with a simple large cap/large choke linearly regulated supply.
stylus drag only becomes a concern when you have low mass platters with high VTF and horrid uncontrolled AC/DC motors.
again its not about the best it's about how well the particular motor is implemented.
for the record, i stopped worrying about such things a long time ago and just listen to the music. there is no perfect speed as all record companies had different cutting lathes and engineers and depending on how good they were at their job you ended up with a large variation in speeds add to that most older records were mastered on tape and the tape was very prone to speed drift.
yes audible vibration threw the system is a problem but this largely depends on the frequency the designer decided to make it.
here is a rundown on most of the AC motors used in the audio industry.
the Premo/philps/airpax are all the same motor now and made by McLennan the numbers 9904 111 318?? are all the same motor but the last 2 digits are the mounting options.
my advice if you ant to stick with AC motors is dump the Hurst and get this and connect it up to your drive.
be careful when fitting the pulley. if you want to know how to do it properly, ask.
again its not about the best it's about how well the particular motor is implemented.
for the record, i stopped worrying about such things a long time ago and just listen to the music. there is no perfect speed as all record companies had different cutting lathes and engineers and depending on how good they were at their job you ended up with a large variation in speeds add to that most older records were mastered on tape and the tape was very prone to speed drift.
yes audible vibration threw the system is a problem but this largely depends on the frequency the designer decided to make it.
here is a rundown on most of the AC motors used in the audio industry.
the Premo/philps/airpax are all the same motor now and made by McLennan the numbers 9904 111 318?? are all the same motor but the last 2 digits are the mounting options.
my advice if you ant to stick with AC motors is dump the Hurst and get this and connect it up to your drive.
be careful when fitting the pulley. if you want to know how to do it properly, ask.
Do they make a 24V version? I have driver for 24V.
why do you think this premotec would be better than my hurst?
also, since you mention it I will ask right away, because I don't know anything about motors nor probably how to fit the pulley....so....is there any special operation I need to do when fitting the pulley.
Last but not least important, with the motor you outlines, I wouldn't have any pulley to go with.
Can I also purchase pulleys for that?
EDIT: Motor is for 50Hz, which means that 60Hz should run at 300RPM, am I wrong? I will check if they make a 24V Version of that at 300RPM
EDIT 2: I don't have to stick with AC Motor necessary 🙂 If there is a nice DC motor solution, why don't we mention it here for the everyone's benefit?
why do you think this premotec would be better than my hurst?
also, since you mention it I will ask right away, because I don't know anything about motors nor probably how to fit the pulley....so....is there any special operation I need to do when fitting the pulley.
Last but not least important, with the motor you outlines, I wouldn't have any pulley to go with.
Can I also purchase pulleys for that?
EDIT: Motor is for 50Hz, which means that 60Hz should run at 300RPM, am I wrong? I will check if they make a 24V Version of that at 300RPM
EDIT 2: I don't have to stick with AC Motor necessary 🙂 If there is a nice DC motor solution, why don't we mention it here for the everyone's benefit?
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Looking at DC motor from Premotec
Motors - DC | Farnell UK | Results
it seems they are much more expensive than AC motor. Why would that be?
What is the best: a lower or higher RPM?
Motors - DC | Farnell UK | Results
it seems they are much more expensive than AC motor. Why would that be?
What is the best: a lower or higher RPM?
dc is controlled by complicated voltage. some people use feedback some use tacho.
McLennan do a 24VAC motor but i don't know if they are available to the public due to Rega using them. you could always ask Rega to buy a spare.
as far as i'm aware 24-110-220vac makes no odds if the supply is crystal controlled as its the amplified frequency that locks the speed and runs the motor.
to fit your pulley is simple. get a spoon ''yes a spoon'' and place it convex side up on a hard surface with a face cloth or something to protect the table surface place the bottom of the spindle on the top of the convex then carefully push the pulley down onto the spindle taking care not to let the motor slip. as long as you make sure that the bottom of the spindle does not move downward while slipping the pulley on everything will be fine. now most motors come so that when the bottom of the motor is resting on a surface the spindle is slightly pushed up, if the motor you get is the same then don't use the spoon but use a piece of metal offcut instead (a coin would do at a push). do not push the pulley too far down and use a 'packer' under the bottom of the spindle to make sure. it's tricky but once you have done a few you soon get the feel.
McLennan do a 24VAC motor but i don't know if they are available to the public due to Rega using them. you could always ask Rega to buy a spare.
as far as i'm aware 24-110-220vac makes no odds if the supply is crystal controlled as its the amplified frequency that locks the speed and runs the motor.
to fit your pulley is simple. get a spoon ''yes a spoon'' and place it convex side up on a hard surface with a face cloth or something to protect the table surface place the bottom of the spindle on the top of the convex then carefully push the pulley down onto the spindle taking care not to let the motor slip. as long as you make sure that the bottom of the spindle does not move downward while slipping the pulley on everything will be fine. now most motors come so that when the bottom of the motor is resting on a surface the spindle is slightly pushed up, if the motor you get is the same then don't use the spoon but use a piece of metal offcut instead (a coin would do at a push). do not push the pulley too far down and use a 'packer' under the bottom of the spindle to make sure. it's tricky but once you have done a few you soon get the feel.
Thanks for the clear description...let me try it and see if I got it right.
I have auditioned in the past P3, P25 and P9 and they all sounded pretty much on the same sonic signature, which is poor, not full body and definitely not neutral.
Companies are on tight budget, while I am not because I do it only for myself and I could afford a suitable $400 motor if it existed.
That said, looking at the same link you provided, this motor seems to have very high torque.
BLDC58-50L - ALLIED MOTION PREMOTEC - MOTOR, BRUSHLESS, 24VDC, 68MM | Farnell UK
Would something like this be suitable or vibration from a big motor like this would overcome the advantage of high torque?
Also, what companies make a good DC motor controller with tachometer built in?
You just got me curious with the DC motor now 🙂
I have auditioned in the past P3, P25 and P9 and they all sounded pretty much on the same sonic signature, which is poor, not full body and definitely not neutral.
Companies are on tight budget, while I am not because I do it only for myself and I could afford a suitable $400 motor if it existed.
That said, looking at the same link you provided, this motor seems to have very high torque.
BLDC58-50L - ALLIED MOTION PREMOTEC - MOTOR, BRUSHLESS, 24VDC, 68MM | Farnell UK
Would something like this be suitable or vibration from a big motor like this would overcome the advantage of high torque?
Also, what companies make a good DC motor controller with tachometer built in?
You just got me curious with the DC motor now 🙂
That is not exactly my experience. I have a 24V 300RPM and a 115V RPM Hurst Motor and both controlled with dedicated controller.
The 24V motor makes far less vibration than the 115V.
True they are driven by two different controller, but they are both crystal locked (one controller is the SDS for the 115V while for the 24 Pyramid's).
what i'm saying is that the controller should not matter what the VAC of the motor is if the controller is crystal amplified then as far as i'm aware its the amplifier that feeds the voltage/current to drive the motor not the mains voltage. but i could be wrong and usually am.
if your going to go DC then give Arthur at the funk firm a phone/email and he will try to help. don't be put off with the motor being a low voltage DC type they work perfect, the controller also has trim pots so you can fine tune the TT speed. most people with Pink Triangle turntables upgrade to the K-Drive, well those that have money to burn. if i had the money i would be doing the same in a heart beat. but since i'm poor then i might just be giving pyramid a PM at some point.
if your going to go DC then give Arthur at the funk firm a phone/email and he will try to help. don't be put off with the motor being a low voltage DC type they work perfect, the controller also has trim pots so you can fine tune the TT speed. most people with Pink Triangle turntables upgrade to the K-Drive, well those that have money to burn. if i had the money i would be doing the same in a heart beat. but since i'm poor then i might just be giving pyramid a PM at some point.
Stefanoo,
Do you have Pyramid's variable frequency drive hooked up? Is it Pyramid's phase management that might be improving the 24V drive?
I still want to look at the Hurst RA series motor as it might have better bearings or bearings that are easier to upgrade. I know it's more torque, which you don't like, but if Pyramid or Daniels variable frequency drives can shape the phase to minimize or eliminate cogging or magnetic field induced noise, it might still be a good, affordable, doable, DIY solution.
Not say that the superior DC drive solution isn't attractive, but where are the DIY solutions using 3 DC drives with synchronized, servo, multiphasic, quantum correcting, solar flair avoiding, moon phase adjusting, unobtainium controllers? If we can't buy, build it, or steal it, it's not much use to us.
Both the funky people and TW acoustics hide the technical details of their products behind heaps of BS, at least on their website. Not to say their TT's aren't the gnat's ***, but what good does that do a DIYer? At least Hurst has complete technical documentation on their website, great customer service, cheap prices, etc. Now that's DIY!
Jamie
Do you have Pyramid's variable frequency drive hooked up? Is it Pyramid's phase management that might be improving the 24V drive?
I still want to look at the Hurst RA series motor as it might have better bearings or bearings that are easier to upgrade. I know it's more torque, which you don't like, but if Pyramid or Daniels variable frequency drives can shape the phase to minimize or eliminate cogging or magnetic field induced noise, it might still be a good, affordable, doable, DIY solution.
Not say that the superior DC drive solution isn't attractive, but where are the DIY solutions using 3 DC drives with synchronized, servo, multiphasic, quantum correcting, solar flair avoiding, moon phase adjusting, unobtainium controllers? If we can't buy, build it, or steal it, it's not much use to us.
Both the funky people and TW acoustics hide the technical details of their products behind heaps of BS, at least on their website. Not to say their TT's aren't the gnat's ***, but what good does that do a DIYer? At least Hurst has complete technical documentation on their website, great customer service, cheap prices, etc. Now that's DIY!
Jamie
Oh, and oops. More to the point of the RA motor. It has optional ball bearings and optional bearings on both ends of the shaft. The Hurst PB motors have a lot of press fit components that are difficult to dis-assembly. I'm speculating that maybe the RA motor is easier to upgrade or hot rod with better sleeves.
I'll repost my Hurst PB autopsy on this thread and I'll get one of the RA motors and post what I can find out. Hopefully it will disassemble easily.
Cheers,
Jamie
I'll repost my Hurst PB autopsy on this thread and I'll get one of the RA motors and post what I can find out. Hopefully it will disassemble easily.
Cheers,
Jamie
we don't use ball bearings in motors for the same reason we don't use them on platter bearings and that's noise... plain bearings all the way, if a plain bearing is greased/oiled correctly there should be very very little noise as the two surfaces never come in contact and instead ''float'' on a thin film of oil/grease. personally i prefer grease but high quality stuff.
Jamie,
I see what you are saying and it makes total sense.
I don't think that controlling 3 motors is the most complicated thing in the world. High quality DC motors can be had and apparently separate controllers can be bought.
Making the housing for the motors, it's a matter to find a ship that will so it for you!
Pulley maybe I see it a bit harder accordingly to what I hear around.
I just don't know how much this solution can cost but definitely less than the $5K external motor by TW and you bet it is still plain diy!
I see what you are saying and it makes total sense.
I don't think that controlling 3 motors is the most complicated thing in the world. High quality DC motors can be had and apparently separate controllers can be bought.
Making the housing for the motors, it's a matter to find a ship that will so it for you!
Pulley maybe I see it a bit harder accordingly to what I hear around.
I just don't know how much this solution can cost but definitely less than the $5K external motor by TW and you bet it is still plain diy!
Jnoneiliv1:
Bibo is correct that ball bearings are not good for turntable motors because of noise. However you could get away with using a bushing type bearing under the pulley and a ball bearing on the bottom of the motor.
For those who understand electronics I would give a serious look on ebay under Maxon motors and controllers. You can get a good high precision motor and controller ( used ) and sometimes new for about $250 U.S. Maxon has good customer service and they could suggest a motor/controller combination to fit your needs. If buy a new motor from them it will be expensive but worth it IMHO.
Bibo is correct that ball bearings are not good for turntable motors because of noise. However you could get away with using a bushing type bearing under the pulley and a ball bearing on the bottom of the motor.
For those who understand electronics I would give a serious look on ebay under Maxon motors and controllers. You can get a good high precision motor and controller ( used ) and sometimes new for about $250 U.S. Maxon has good customer service and they could suggest a motor/controller combination to fit your needs. If buy a new motor from them it will be expensive but worth it IMHO.
i looked at the Maxon off the shelf DC stuff ages ago and it looks very very nice and fairly well priced. IIRC RS components sell them.
i actually have a cunning plan for a shaft support. i'm going to get a grub screw and fit a sapphire jewel in the indent, that should be much much better than a ball bearing.
i actually have a cunning plan for a shaft support. i'm going to get a grub screw and fit a sapphire jewel in the indent, that should be much much better than a ball bearing.
Bibio:
I see our minds think alike !! If you do a precise fitting of the jewel / shaft it will work.
My turntable bearing uses a 5" long carbide shaft that I brazed a 3/4" piece of bronze that was machined to a cone. I center drilled the bronze cone and installed a 1/4" sapphire ball. I used 2 100lb pull ring magnets where one was installed on the shaft and the other was machined into the base of the bearing housing. I used a 5/8" bronze cup with a Teflon plate installed that screwed into the bottom of the bearing housing which enabled me to screw the cup in to just kiss the sapphire ball of the shaft. This enabled me to totally float my 44lb platter with magnetic repulsion and have a 1lb pressure and a zero reference point on the bottom of the bearing. Worked like a charm !!!
I see our minds think alike !! If you do a precise fitting of the jewel / shaft it will work.
My turntable bearing uses a 5" long carbide shaft that I brazed a 3/4" piece of bronze that was machined to a cone. I center drilled the bronze cone and installed a 1/4" sapphire ball. I used 2 100lb pull ring magnets where one was installed on the shaft and the other was machined into the base of the bearing housing. I used a 5/8" bronze cup with a Teflon plate installed that screwed into the bottom of the bearing housing which enabled me to screw the cup in to just kiss the sapphire ball of the shaft. This enabled me to totally float my 44lb platter with magnetic repulsion and have a 1lb pressure and a zero reference point on the bottom of the bearing. Worked like a charm !!!
heats off to you. I have not really understood exactly everything but it sounds pretty awesome.
I mean having a sapphire on the motor shaft might seems a bit too much if it's hard to get a pulley made well, I can't imagine the difficulty of making a sapphire properly fit on the motor assembly. 😱😱
Speaking of more realistic things perhaps, a very high quality DC motor with no ball bearing nor sapphires ehehe...may seem to be the best solution (?!?)
But where could I have a new pulley made? Any thoughts?
sefanoo:
That depends on your skill level. You will need some hand tools, some files, a hand expandable reamer that will adjust to your motor shaft diameter, drill bit just slightly under the shaft diameter and a saw to cut the aluminum, a dial caliper or micrometer, some different grades of sand paper and patience. Once you have a close estimate as to the size pulley you need you can buy a rod of aluminum slightly larger in diameter. Then cut a piece thick enough for your pulley height, you drill a hole in the center of your pulley blank and ream the hole so it is a snug fit on your motor shaft. Then mount the pulley blank on the motor shaft, turn on the motor and gently put the file and sand paper to the pulley and reduce the diameter to what you need. This way it will concentric to your motor. I will take some time but will work or you can get a small table top hobby lathe ( ebay )and make life a little easier. If you plan on making a number of small precision parts for future projects a small lathe is the way to go. When you see the prices some machinist charge it may pay to invest in some good tools. You will probably have to make more then one pulley to get it perfect.
This kinda makes you think how the clock makers in the 1700's did it. Good luck.
That depends on your skill level. You will need some hand tools, some files, a hand expandable reamer that will adjust to your motor shaft diameter, drill bit just slightly under the shaft diameter and a saw to cut the aluminum, a dial caliper or micrometer, some different grades of sand paper and patience. Once you have a close estimate as to the size pulley you need you can buy a rod of aluminum slightly larger in diameter. Then cut a piece thick enough for your pulley height, you drill a hole in the center of your pulley blank and ream the hole so it is a snug fit on your motor shaft. Then mount the pulley blank on the motor shaft, turn on the motor and gently put the file and sand paper to the pulley and reduce the diameter to what you need. This way it will concentric to your motor. I will take some time but will work or you can get a small table top hobby lathe ( ebay )and make life a little easier. If you plan on making a number of small precision parts for future projects a small lathe is the way to go. When you see the prices some machinist charge it may pay to invest in some good tools. You will probably have to make more then one pulley to get it perfect.
This kinda makes you think how the clock makers in the 1700's did it. Good luck.
hottatoo,
this is just not my cup of tea. I have no experience with what you described, nor any of the tools required.
It would be impossible for me to do that at this point, that is why my initial idea of hot-rodding the hurst was the best bet for lots of people like me who don't have access to that kind of diy.
Maybe another option for people like me, would be to find replacement pulley and motor from another hi end TT and build housing around....or going back to the original topic, since the hurst motor with phase control is not extremely bad, how to hot rod this motor to make it better.
this is just not my cup of tea. I have no experience with what you described, nor any of the tools required.
It would be impossible for me to do that at this point, that is why my initial idea of hot-rodding the hurst was the best bet for lots of people like me who don't have access to that kind of diy.
Maybe another option for people like me, would be to find replacement pulley and motor from another hi end TT and build housing around....or going back to the original topic, since the hurst motor with phase control is not extremely bad, how to hot rod this motor to make it better.
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