Turntable Wow and Flutter "Polar" Plot Script

[JP]

Something like this. I used a helping hand to hold the ruler stationary.

 

[Balle Clorin]

The problem still is where to push/adust? Do you do that while spinning or manually turning platter?

 

[JP]

Manually. Adjustments are made perpendicular to the groove where the stylus is.

 

[morillon]

By sticking a piece of tape (typically 0.04mm thick sometimes less) on like 1/3 or 1/4 of the axis and trying different positions of the disc, would that work?

 

[SeriousSeri]

Depending on how accurate you want to be, just use an App like "RPM Speed and Wow".
I have a 360° Disc that i used in the past. I just put it on the record, push the LP to the Pin in the 0° Position and make a measurement. Then you do 90° Steps and do the newton iteration from there (always take the half angle of what you measured best before).

This will give you the best general degree for the record, but ofc this can still mean you're out of center, but as a start thats easy.

ofc you can also go crazy and use something like a DS Audio ES-001 Eccentricity detection stabilizer.

 

[Digital1955]

I'm thinking about checking and adjusting the BSL motor gain and dc offset settings on my 44 year old Sony PS-X50. Before pulling it apart I've been messing around with this script to try to get some before and after. I don't have any LPs with the official 3150hz tone. I was going through what I do have, and this was the best I could find. Here is what I got with the stock script. I also modified the script so that the radial axis is scaled from the min to max values for a different perspective.

 

[JP]

Updated first post to reflect that the script code is now located at https://ttpolarplot.com. Issues that require code changes should also be reported there.

 

[Timmy]

my 44 year old Sony PS-X50

Great! Mine is a PS-X60.

Just did a »measurement« using one of those smartphone apps. Not sure if there’s any need now for me to go into deeper survey ...

 

[morillon]

what is delicate is really the centering balancing of the phone on the plate as best as possible...
it is likely that after some effort you will gain some 0.0*%... (see effortss on the refreshing of the electronics..and a care on the lubrication..... if not do)

but 0.05% in sigma2 for an old lady is already good
;-)

 

[morillon]

you can try "rpm wow"... to the more detailed result...not only 2sigma ;-)

 

[Timmy]

you can try "rpm wow"... to the more detailed result...not only 2sigma ;-)

Found no way to do that with the given app: »RPM Speed and Wow«.

Here’s a 45 rpm measurement result:

 

[morillon]

for android

 

[morillon]

Comparing the two applications is interesting anyway

 

[ban25]

Found no way to do that with the given app: »RPM Speed and Wow«.

Here’s a 45 rpm measurement result:

View attachment 390109

Also don't forget to check the graph.

 

[USER]

Thanks for the updated script, @JP.

I have a couple of questions regarding some of the changes.

1. As rev offset is off by default, what would be a good reason to use it?
2. I am getting very different results in the mean frequency legend. Am I missing something (see below)?

The following are results on the new script with the legend and revoffset settings vs the results on version 5C of the script (with minor aesthetic changes).

 

[JP]

1. As rev offset is off by default, what would be a good reason to use it?

Where you want to plot a small number of revolutions deeper in to the test track - easier than editing the file. Also good for low frequency measurements were the filter takes a few revolutions to settle.

2. I am getting very different results in the mean frequency legend. Am I missing something (see below)?

Strange. Don't think I've touched that since Scott added it.

 

[USER]

Strange. Don't think I've touched that since Scott added it.

Maybe this will help locate the issue. It works when pltpolar is turned off.