Fun with vinyl measurements

[Balle Clorin]

Must be very hard to oberve where to push the record, I cannot manage that I think..

 

[thewas]

A human Nakamichi Dragon CT / TX-1000!

 

[Thomas_A]

Must be very hard to oberve where to push the record, I cannot manage that I think..

Requires a slip or felt mat. It works quite well once you get the feeling for it. This will however be only for setting the 3150 Hz track for comparison of wow and flutter. I have the Linn Axis which have a 1050 g outer aluminum platter. I haves soon have the 2500 g LP12 alloy outer platter here to compare with. Significant increase in moment of inertia...

 

[Balle Clorin]

My Clearaudio Trackability test record has a side 2 with a endless 3150hz and groove at the outer edge to observe the cartridge sideways movement , but it is still very hard to judge where and how much to adjust the record… I am rarely successful

 

[Thomas_A]

A human Nakamichi Dragon CT / TX-1000!

Haha. yes... but the idea with a USB microscope is not new. @scott wurcer have done it on the cartridge, I believe.

 

[Thomas_A]

My Clearaudio Trackability test record has a side 2 with a endless 3150hz and groove at the outer edge to observe the cartridge sideways movement , but it is still very hard to judge where and how much to adjust the record… I am rarely successful

Watching the cartridge is also a method but I am a bit worried to damage the cart when doing the correcting pushes. The USB microscope on the lead out groove just needs the record spinning.

 

[Thomas_A]

It gets quite circular when aligned (although some variations are there, but that seems normal for my standard Linn Axis). Also need to adjust speed - I managed to fix the PCB finally, but have not adjusted the pots yet.

 

[JP]

Bit less precise but works good enough:

 

[Balle Clorin]

It gets quite circular when aligned (although some variations are there, but that seems normal for my standard Linn Axis). Also need to adjust speed - I managed to fix the PCB finally, but have not adjusted the pots yet.
View attachment 312696

Can you please post the polar script here? I did something to mine and it does not work anymore. Something with Home/File directory I suspect. I tried to put script and wav file in same folder but still not working..

 

[USER]

Not sure it is the latest version but here is 5C:

MM vs MI vs MC

@JP , this "HOME" thing is drving my crazy I cannot get the file or folder path to work , How can I fix this? This is the Polar RPM plot script

www.audiosciencereview.com

 

[Balle Clorin]

My Clearaudio LPT43039 Trackabilitt test record side 2 3150Hz give this today with n 0.5mm offcenter movement at the run out groove, Audacity WF addin .Denon DP-51F

Shaknspin

I will try my B&K QR2010 3150Hz next. EDIT: her is is . Half the wow compared to Clearaudio. I thing Shaknspin is the tool to use..
The B&K speed is way off, my DENON is spot on with the KAB strobelight( EDIT had the wrong ref speed 3000 not 3150)

Conlcusion: test record are crap use gyro/accelerometer for W&F, and strobedisk for absolute speed..

But you can get lucky.. her o pushed theQR2010 record towards me on the platter

 

[Balle Clorin]

My Michell Gyro Belt drive on a good day vs Denon DP-51F Direkt drive. Belt is less consstent av vary more, during play, song , hour ,day. DD is the same all the time.
Tried to center record, this was the best I got on both tables,

 

[Thomas_A]

My Michell Gyro Belt drive on a good day vs Denon DP-51F Direkt drive. Belt is less consstent av vary more, during play, song , hour ,day. DD is the same all the time.
Tried to center record, this was the best I got on both tables,
View attachment 312821

A good direct drive always beats a belt drive in consistency, but LPs are always prone to wow (0.56, 1,1 Hz), unless you center all of them before play. I wonder about the peaks in the 3-20 Hz range though.

 

[Thomas_A]

First test with Tacet record (aligned with USB microscope). Linn Axis with the light aluminum platter. Know it is too slow but will adjust. Mostly 1.1, 2,2 Hz.

 

[Balle Clorin]

Nice explanation here.Seems like the lower right plot is the raw data and the needle is the thing affected by the choice of methods

https://reflectiveobserver.medium.comwow-flutter-explained-31cc9495d24

 

[Thomas_A]

Nice explanation here.Seems like the lower right plot is the raw data and the needle is the thing affected by the choice of methods

https://reflectiveobserver.medium.comwow-flutter-explained-31cc9495d24

Can’t open link.

Ah ok that link, found it. It is very useful info.

 

[Thomas_A]

@Balle Clorin did you try the logger and extract the data over time? It extract the values every 1 s window and writes it to a text file. Since values fluctuate it would be interesting to follow the values from start to end of the track. I will try visualising that during the week.

 

[Balle Clorin]

Logger is useful for beltdrives since they drift. With DD it is rock stable for me. Not sure why the link fails now

Try again

Wow & flutter explained

Wow & flutter and how to measure it.

reflectiveobserver.medium.com

 

[USER]

I need to find a good stand/holder for the microscope so this is not optimized, but not too shabby for 40+ year old Sony PS-X50.

@Thomas_A: does that peaking at 50Hz mean anything to you? This is a direct drive.

 

[Thomas_A]

I need to find a good stand/holder for the microscope so this is not optimized, but not too shabby for 40+ year old Sony PS-X50.

View attachment 313178View attachment 313179


@Thomas_A: does that peaking at 50Hz mean anything to you? This is a direct drive.

Not sure what you mean. Can’t see 50 Hz in your spectrogram.