Fun with vinyl measurements

[watchnerd]

I'm interested in how a laser record player measures. I owned a Lineal in the last century and it certainly performed better than my stylus record players with scratched or worn records, particularly 78s but the sound quality didn't scale with price.

I would assume it would be similar to other TT's with the same drive mechanism.

I don't see how the laser would matter much.

 

[Prep74]

I would assume it would be similar to other TT's with the same drive mechanism.

I don't see how the laser would matter much.

Well the cart combo would be different. Less IGR for a start, maybe better FR and SNR due to less friction on the grooves and the ability to read deeper into them.

 

[watchnerd]

Well the cart combo would be different. Less IGR for a start, maybe better FR and SNR due to less friction on the grooves and the ability to read deeper into them.

Oh, I thought you were just talking about W&F.

Does a laser read deeper into a groove than an advanced stylus shape?

Not so sure about that.

 

[Prep74]

Oh, I thought you were just talking about W&F.

Does a laser read deeper into a groove than an advanced stylus shape?

Not so sure about that.

Yep, laser TTs are better for transcribing 78s for that very reason. I think it is not only that it reads deeper, but that it follows the groove undulations better than a stylus, particularly a conical stylus. I know that I could play worn or damaged 78s that were unplayable on regular players.

 

[watchnerd]

Yep, laser TTs are better for transcribing 78s for that very reason. I think it is not only that it reads deeper, but that it follows the groove undulations better than a stylus. I know that I could play worn or damaged 78s that were unplayable on regular players.

78s are mono and have much much fatter grooves than micro-groove stereo 33 1/3 RPM records.

78s were designed for use with simple fat styli and a big fat laser dot can fit into that big fat groove.

An advanced Shibata stylus, on the other hand, was designed for 4 channel quad and can read into the ultrasonic.

 

[Balle Clorin]

Performance after starting one early morning, the first 10-20 seconds the speed is not stable until oil is pumped to the bearing.

 

[watchnerd]

Performance after starting one early morning, the first 10-20 seconds the speed is not stable until oil is pumped to the bearing.

View attachment 153836

Good to see this measured, as I could always just tell by sound.

What kind of oil are you using?

 

[Balle Clorin]

same as Michell, Mobile 1 0w-40

 

[Balle Clorin]

Updated with speed histogram plot with 3150 Hz and 33.33 peak with same x axis range as HifiNews( 3100-3300 Hz or 95-105%).... far right...
Speed deliberately set at 33.38 to match 33.33 with needle in groove. Speed stable from day to day now(within 0.03%)

Speed variation during ONE revolution,, is guess there is some noise in the speed data? Sampling frequency 500 Hz( every 2 milliseconds).
That is 900 samples per platter revolution. Black line is mooving average of 25 samples or 50mSec= 10 degrees rotation

 

[JP]

@Balle Clorin can you provide a recording of the W&F track?

 

[Balle Clorin]

There is no recording in analog sense. Shakenspin is a rotational recorder based on a 6 axis sensor that logs data(revolution speed rpm) every 2 millisecond.( every 0.4degre or 1/900th rotation)
What is recorded is 4000 samples of RPM for 8000 msec period. Here is snapshot of the data. raw value blue, green low pass filtered, blue 25 point mooving average. I can share the file by mail if you like

Here is how 150 datapoints or 0.3secconds or 60degree or 1/6th rotation look like

 

[JP]

There is no recording in analog sense. Shakenspin is a rotational recorder...

Yes, I know how the Shakenspin works. Perhaps I should've said "a" instead of "the".

 

[stereoplay]

Here are some Wow&Flutter measurements done with my best record regarding speed stability (Tacet).

We see a Thorens TD180, Dual CS731Q and Pioneer PL-L 1000.

Greetings
Frank

 

[Thomas_A]

Here are some Wow&Flutter measurements done with my best record regarding speed stability (Tacet).

We see a Thorens TD180, Dual CS731Q and Pioneer PL-L 1000.

Greetings
Frank

Nice software. What is it?

 

[stereoplay]

It's a self-written software.

 

[stereoplay]

I have quiet a lot of speed measurement test records. Some time ago, I put them on a Grundig PS4500 (Aka Technics SL-Q2) to see what happens: All of them showed different values.
So what I can say from my side of view: Be careful with the test records you are using to measure speed.

 

[Balle Clorin]

Very nice plots Which program/software do you use?

 

[stereoplay]

Hello,

As I said before, it is self written.

Currently I am working on an improved measurement technique with an encoder disc.

 

[Balle Clorin]

Fantastic skills!! Impressive

The «Ultimate Test record” and Tacet seem decent

! keep it coming, great work thanks

 

[Balle Clorin]

just needed a place to put my last presentation of W&F