Fun with vinyl measurements

[Thomas_A]

Did AI come up with this? It cannot be that simple.. ? The phase diff will vary with frequency. , tracking error does not

It was only for 1 kHz, another answer was that it scales with frequency. 10x higher at 10 kHz.

 

[Thomas_A]

Been playing around tonight, realigned, measured etc, and this is my final vote what I get from the AP 1 kHz track. Around 3.5 degree phase error.

 

[Balle Clorin]

Good to know that the script does detect changes to the alignment, the suspicious thing is that 1 degree phase error is A quite large alignment error yaw/zenith/hat or whatever we call it.. so I am note sure how accurate the result is in a absolute value,,

 

[Thomas_A]

Good to know that the script does detect changes to the alignment, the suspicious thing is that 1 degree phase error is A quite large alignment error yaw/zenith/hat or whatever we call it.. so I am note sure how accurate the result is in a absolute value,,

I am still trying to figure out calculations of theoretical inter-phase difference. At 1 kHz and 7 cm/s. Last calc from AI gave 2 degree in outer groove with some error estimate betwen 2-4 degree.

 

[Balle Clorin]

My effort to calculate it is in post 2265

 

[Balle Clorin]

Relation tracking error and phase difference

 

[Thomas_A]

Relation tracking error and phase difference

Where does level come in?

 

[Balle Clorin]

Modulation swing is not included. That would become too complex for me, simplified to simple linear path

 

[Thomas_A]

A test with the 7 stereo track 1 kHz signals from the CA-TRS1007 record. There was a 360 and 720° phase shift in the software for the 4-5 and 6-7 tracks, respectively (needed to cut away the irrelevant tracks). The tracking error given in pink at approximate distance (red) and the inter-channel phase difference in blue (minus the 360/720°). IC phase difference does not vary more than 1 degree between outer groove and middle grooves. I estimated distance and tracking error and null ends up at between just below 122 mm vs. theoretical 121.754, so I am quite good at measuring the distance here.

According to this record I am off by -1.25 degrees at stylus/geometry if I should hit 121.754 mm with zero phase diff. Or 1.25°/2 = 0.625° because stereo walls? Clear is that this is a very different result vs. the AP record. Now how to calculate the direction of the turn; positive R leads L? If I think correct, R lags behind so that would be CCW turn. 1.25° or rather 0.625° not easy to dial in manually though.

 

[Balle Clorin]

Dis you use my equation to calculate tracking error from phase difference?

 

[Thomas_A]

Dis you use my equation to calculate tracking error from phase difference?

I tried but had a lite problem with your handwriting...


so I got a bit wacko values.

 

[Balle Clorin]

I have a problem withmy handwriting Myself …Igbo k I got too high errors on the angle

 

[Balle Clorin]

Relation tracking error and phase difference

@Thomas_A aboute Alpha tracking erroe and these difference Phi, AI gives this.. so I think my formula may be correct (180/PI is radian to degree conversion)



I asked : vinyl record playback. The horisontal tracking angle HTA error caused by the pivoting tonearm will cause a misalignment and time difference between the right (outer )channel and the left(inner) channel. at a given frequency thei time difference is represented by phase difference between the right and left channel. Can you give me a formula to calculate the angular HTA error as a function of the phase difference?. I assume the equation need to incorporate both frequency and the cartridge radial position and record rpm
Answer:

 

[Thomas_A]

I don't really get it. Are you calculating tracking error or inter-channel phase difference?

 

[Balle Clorin]

My script calculated the inter channel phase difference, the equation converts the inter channel phase difference to tracking error ar a given radius, Ai calculates in radians so the last term 180/pi converts from radians to degrees and is not required if your calculator thinks in degrees.
Ithe script have no way of knowing at which radius and their by velocity the race in the groove so that’s why I have to use this formula to find the tracking error. But I thought the formula was wrong since I got so large errors that’s why I did not post it before.

 

[Thomas_A]

Is it possible to plot the tracing error and inter-channel phase error in the same graph? As I got with the 1 kHz signals from the CA-TRS1007 the phase error is within 1 degree or so while tracking error is varies 3 degrees within the range 146 mm to 98 mm. When time allows I will twist the cartridge slightly and redo the analysis with a goal of getting the zero crossing the same for both.

 

[Balle Clorin]

Should be possible but I have not worked out how to get the script find the radius vs time ( radius give V groove velocity at RPM) , I am missing the groove spacing..

 

[Thomas_A]

Should be possible but I have not worked out how to get the script find the radius vs time ( radius give V groove velocity at RPM) , I am missing the groove spacing..

Is d(w) groove width, which is correlated to cm/s?

 

[Balle Clorin]

Dw is groove width yes, I use Groove velocity V that is 2PiR /1.8sec for 33 rpm. Modulation or signal level in cm/s is not used in the calculation

 

[Balle Clorin]

I got this record today ( record 51 of 300! Direct metal master) my purpose was to evaluate distortion across the record - for HTA error evaluation as Korf tried -( without seen the text book response).

But in this video the company stated that azimuth affect channel balance , something I have not observed in any if my testing…
You my question to you is, does Azimuth really affect channel balance is shown here ?