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Helping a DC motor

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jupiterboy View Drop Down
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    Posted: 06 Jul 2022 at 7:01pm
I've got a turntable in the house, and I'm waiting on the tonearm to be finished/shipped. I'm trying some different bearing oils and power supplies to establish a baseline of performance.

Measuring wow and flutter is not well standardized, but I have used some apps like RPM in the past to establish a baseline so I could quickly check and see if belt slippage or other possible issues are deteriorating performance. 

My power is pretty basic—20 amp dedicated line with a ZeroSurge unit for filtering and protection (big caps rather than MOV). I've got a power strip running off the ZeroSurge with a bunch of source components and wall warts. 

I'd like to improve the power to the table with the goal of making it easier on the motor and possibly improving the measured wow and flutter. Maybe the cheapest way to wade in is to add a ferrite core, but what size, what materials, how many wraps, where on the power wire do I place it? Seems like too much experimentation. I don't have O scope. Are there any basic guidelines or ways to measure that I might not know of?

The power supply look like a basic switching wall wart—12V, 420mA. This low current appears to be be below what most LPS solutions can provide, and I'm thinking it needs to be current limiting as the back of the table specifies "less than 500mA".
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Fatmangolf Quote  Post ReplyReply Direct Link To This Post Posted: 06 Jul 2022 at 8:29pm
How are you controlling the speed?
Jon

Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jupiterboy Quote  Post ReplyReply Direct Link To This Post Posted: 06 Jul 2022 at 9:30pm
It has a speed selector switch and two trim pots for 33 and 45. 

Seems to start a little fast then settle down. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jupiterboy Quote  Post ReplyReply Direct Link To This Post Posted: 07 Jul 2022 at 12:10am
I could probably run it off an Enigma, but I don't fully comprehend how the whole motor circuit works and if this would be starving it of current or be just fine. 
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Post Options Post Options   Thanks (1) Thanks(1)   Quote patientot Quote  Post ReplyReply Direct Link To This Post Posted: 07 Jul 2022 at 1:44pm
AFAIK Measuring wow and flutter professionally is done with a lab grade test record and a wow and flutter meter. That can be expensive, so might not be practical for home testing unless you know someone with the gear already.

Some folks have had success with the program WFGUI here:


However the downfall of this program is obtaining a flat, well centered test LP. Results will entirely depend on that test LP and many commercially available test LPs for audiophiles might not be well centered. If you can find a well centered one with a 3150Hz or 3000Hz test tone that would work.

There is a guy out of Europe that designed this device, which if it works would be a useful tool and worthwhile investment for those that use BD type turntables.


I can't say I'm a fan of those smartphone apps as they have a number of issues. They are only as accurate as the phone's gyroscope, which can vary a lot, and they require precise placement of the phone on the center of the turntable's spindle to achieve accurate results. I've seen many examples of bunk results with those things.

Personally I'm glad I don't have to worry about W/F too much. My turntable has a sophisticated computer system built in. Putting it into service mode and then running the speed program spins up the platter automatically and runs a bunch of different speed tests which calibrates things for me. This is done at the factory already but I did it myself for amusement.


Edited by patientot - 07 Jul 2022 at 1:45pm
Reflex M + PSU-1 used with AT150-40ML, AT VM95ML, Stanton 680mkII + Ogura, and Shure M35X cartridges.
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jupiterboy View Drop Down
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Post Options Post Options   Thanks (1) Thanks(1)   Quote jupiterboy Quote  Post ReplyReply Direct Link To This Post Posted: 07 Jul 2022 at 2:25pm
Originally posted by patientot patientot wrote:

AFAIK Measuring wow and flutter professionally is done with a lab grade test record and a wow and flutter meter. That can be expensive, so might not be practical for home testing unless you know someone with the gear already.

Some folks have had success with the program WFGUI here:


However the downfall of this program is obtaining a flat, well centered test LP. Results will entirely depend on that test LP and many commercially available test LPs for audiophiles might not be well centered. If you can find a well centered one with a 3150Hz or 3000Hz test tone that would work.

There is a guy out of Europe that designed this device, which if it works would be a useful tool and worthwhile investment for those that use BD type turntables.


I can't say I'm a fan of those smartphone apps as they have a number of issues. They are only as accurate as the phone's gyroscope, which can vary a lot, and they require precise placement of the phone on the center of the turntable's spindle to achieve accurate results. I've seen many examples of bunk results with those things.

Personally I'm glad I don't have to worry about W/F too much. My turntable has a sophisticated computer system built in. Putting it into service mode and then running the speed program spins up the platter automatically and runs a bunch of different speed tests which calibrates things for me. This is done at the factory already but I did it myself for amusement.


Might have to set up a Windows OS on a partition to run software. I can't tell if the shaknspin app is Apple friendly.

My take on the phone apps is that, yes, the w&f is largely useless. That said, I've center drilled a sponge the size of my phone, so that goes over the spindle and under the phone. I'm getting repeatable results, even if less than accurate, so it is a sort of baseline. I still think the phone weight can't be centered, so it probably punishes some bearings more than others. 

Thanks for the leads.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote patientot Quote  Post ReplyReply Direct Link To This Post Posted: 07 Jul 2022 at 2:30pm
Originally posted by jupiterboy jupiterboy wrote:

[
Might have to set up a Windows OS on a partition to run software. I can't tell if the shaknspin app is Apple friendly.

My take on the phone apps is that, yes, the w&f is largely useless. That said, I've center drilled a sponge the size of my phone, so that goes over the spindle and under the phone. I'm getting repeatable results, even if less than accurate, so it is a sort of baseline. I still think the phone weight can't be centered, so it probably punishes some bearings more than others. 

Thanks for the leads.



^I think that will work for your apple device? Note that the SNS device is doing the actual measurement, it's just sending info to the app.
Reflex M + PSU-1 used with AT150-40ML, AT VM95ML, Stanton 680mkII + Ogura, and Shure M35X cartridges.
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