The W&F Analyzer Project, Uberrimus

[Thomas_A]

There is unfortunately, that I know of, not a better replacement belt for the Linn Axis (or LP12). I had hopes for the Thakker belt but the 0.5 and particularly the 1.0 Hz component increased significantly. I also think the Thakker belt was slightly longer than the Linn Belt. Values below are for just visual centering without the USB camera, so the 0.55 Hz component is a bit different. The point is though that the 0.5/1.0 Hz is huge on the Thakker belt. So no cheap alternative yet.

Thakker belt, new:

Original Linn belt 3 years old:

 

[Balle Clorin]

That was A horrible belt… most 3rd part belts are

 

[Thomas_A]

That was A horrible belt… most 3rd part belts are

I've tested a cheaper and even worse though, posted in the "Fun thread" in February 2023. It was the same time I acquired a new Linn original belt (the old belt was significantly stretched when comparing them).

At least the Thakker belt had the same dimensions (1 mm thick, 5 mm wide) as the original, but it might be some mm longer. So I had hopes for it. But I do not think it is the same material and compliance and it seems to be poor.

Now what is the lifespan of a belt? Should I buy a new Linn belt for €80 and test against the 3- year old one? If no difference I can just save it until it is time for change. I think Linn says 5 years.

 

[Thomas_A]

Now for something suprising. The old Linn belt vs. a completely new original Linn belt. Perhaps there is a first timer for a "run-in"? My hope this is an original Linn belt...

The old belt:

The new belt:

Old belt again:

 

[Thomas_A]

Spent an hour to more precisely adjust the inner chassis to align the pulley with the inner platter. Running in the new belt like this and I will measure again after a months regular use.

 

[Thomas_A]

Taking a break for a couple days from this. Hung out with a friend on Thursday who's in the industry, and one of the outcomes was the idea to simulate W&F profiles for listening tests so people can understand their sensitivity. I made a script that uses the 16 peaks from the FM demodulated plot data from wf_core to build a profile. You can then use that profile to apply simulated wow and flutter at different DIN metrics to audio files.

Here's an SP-10MKII FG profile simulated from 0.05% to 1.5% in 16 increments. The test is to choose which is the reference file vs. the higher W&F files.

acidtest.io listening tests

I thought I saw the spectrum of the FG in this thread, but now cannot find it. Will try a bit more serious to see my limit. A steady synth tone may be more audible than a piano that may contain some wow in sustain.

 

[Balle Clorin]

Here recorded 1000hz track from Technics SFC TR-100,, simultaneously as I made Shaknspin data collection.

on 2 turntable belt and DD. zoom in for details… Record quality matters a lot, but record also show other things than just speed, vibrations etc.

Spoiler: vibrations recording

Belt simulator

'

 

[morillon]

The belt should be stored in both directions, turned over, to see which is the best orientation?
;-)

 

[Balle Clorin]

what do you mean ? it is a round belt , no onside or outside. I have 3 grooves in platter, so i can choose the best. Groove choice and time since talcum treatment affect both speed and vibrations, as do motor position and pulley size. A belt drive keeps me busy.. that is part of the fun, I use DD when I am tired of belt hazzle

 

[Balle Clorin]

can we elderly get more contrast?, it is hard to read the axis valaue and metrics.. small letters and grey-on-black, in Black mode.. is there any White mode ?

Not so much and iissue on the webpage, but when cutting and pasting snapshots they soon become hard to read if not made full page

 

[Erogen]

Measuring the parameters of the Victor QL-A95 turntable using a smartphone app placed on the platter's axis.
The turntable is a Japanese import. The measurements were taken right out of the box, without any service, and as received.

Perhaps this measurement will be useful to someone.

 

[Balle Clorin]

Congratulations!

 

[dougi]

This is fantastic and much appreciated. What is the best test record for it though? I have the Elipson one which has 3150 Hz, but the centre hole is so big I get really bad results. E.g. on my vintage Denon direct drive I get 5-8 times worse than an app. Mostly 0.55 Hz so centering, but also a seemingly large 7 Hz component, which seems strange.

 

[Thomas_A]

This is fantastic and much appreciated. What is the best test record for it though? I have the Elipson one which has 3150 Hz, but the centre hole is so big I get really bad results. E.g. on my vintage Denon direct drive I get 5-8 times worse than an app. Mostly 0.55 Hz so centering, but also a seemingly large 7 Hz component, which seems strange.

If you get a slippery felt mat you can easily center your record by lightly tapping it while it's running. I watch the run-out groove with a USB microscope while doing it.

 

[Balle Clorin]

I must be doing it wrong .. when I try that I miss the correct tapping spot/ timing and cannot get it properly centered. The results are all over the place..

I end up shifting the record stationary in different clock positions/directions and trial and error.. I feel I may miss the optimal point somewhere

I have a Delrin platter which allow some movement, but maybe felt mat is better

 

[Thomas_A]

I must be doing it wrong .. when I try that I miss the correct tapping spot/ timing and cannot get it properly centered. The results are all over the place..

I end up shifting the record stationary in different clock positions/directions and trial and error.. I feel I may miss the optimal point somewhere

I have a Delrin platter which allow some movement, but maybe felt mat is better

It is a bit of a learning curve to tap it at correct place while watching the spinning inner groove. A felt mat helps since it allows quite small movements during light tapping. I usually do the process under a minute but then I know where to tap and how much.

 

[somebodyelse]

I guess that only works with an oversize hole, or a removable centre pin I vaguely remember - was that on the Roksan Xerxes?

 

[Balle Clorin]

GitHub - FidelisAnalog/AES6-Wow-and-Flutter: AES6-2008 / DIN / IEC Wow and Flutter Meter

AES6-2008 / DIN / IEC Wow and Flutter Meter. Contribute to FidelisAnalog/AES6-Wow-and-Flutter development by creating an account on GitHub.

github.com

Use fg_analyze_vectorized.py

which file shoud we use now?," fg_analyze_vectorized.py" is gone..
what to do with what were in this github thing is not obvious to me..will there be a for dummies guideline how to implement this stuff? or are we dummies to use the webapp?

edit ,, feel even dumber now..

copied wf_core to my pythn folder and got this

 

[JP]

The readme that displays automatically below the file list is insufficient?

 

[Balle Clorin]

No it is 85% Greek to me. I did not understand command line before 30 minutes ago. I will try more tomorrow