Frequency Response Test Records

[Balle Clorin]

Sweep below 800hz is not an issue. See Clearaudio ca trs-1007

 

[mischa]

Will the skating force decrease towards the end of the record ?

 

[Heinrich]

Will the skating force decrease towards the end of the record ?

No, but yes. Antiskating is related to the tonearm’s offset angle and to friction. The latter varies mainly with groove modulation, not so much with linear speed as a function of groove radius. Antiskating—like almost everything in vinyl playback—is only an approximation. Obsessive over-optimization is an expensive hobbyhorse, and compared to digital the results will be a letdown anyway.

 

[Balle Clorin]

Skating force is simple.it is F*u*Sin( Alpha)

Where Alpha is offset angle +tracking error.Set antiskate force at 12-13% of VTF and you are good. Most of tonerarms manuals recommendedtions applies 10-15%when used as recommended.
This means the skating force follows the tracing angle error shape across the record

 

[mischa]

No, but yes. Antiskating is related to the tonearm’s offset angle and to friction. The latter varies mainly with groove modulation, not so much with linear speed as a function of groove radius. Antiskating—like almost everything in vinyl playback—is only an approximation. Obsessive over-optimization is an expensive hobbyhorse, and compared to digital the results will be a letdown anyway.

Tank you!
So the friction is not so speed related.

Skating force is simple.it is F*u*Sin( Alpha)

Where Alpha is offset angle +tracking error.Set antiskate force at 12-13% of VTF and you are good. Most of tonerarms manuals recommendedtions applies 10-15%when used as recommended.
This means the skating force follows the tracing angle error shape across the record

Thank you!
I was able to measure the antiscate force with a cheap digital
stylus force scale gauge.
I don`t know how acurate this is,
but it was almost as the recomendet force for the tonearm.
VTF 1.25g
technics sl 1410mkII turntable antiscating scale at 1,6 is 1,3g antiscating force.
Ortofon Test record at 60µm peak was OK.

EDITH : 0,13g antiskating force not 1,3g.

 

[Thomas_A]

Tank you!
So the friction is not so speed related.


Thank you!
I was able to measure the antiscate force with a cheap digital
stylus force scale gauge.
I don`t know how acurate this is,
but it was almost as the recomendet force for the tonearm.
VTF 1.25g
technics sl 1410mkII turntable antiscating scale at 1,6 is 1,3g antiscating force.
Ortofon Test record at 60µm peak was OK.

If you can use a blank space at the runout section you can also confirm. At that large antskate force, 1.3 g, it should skate outwards when stylus is put down on a blank space. At VTF 1.25 your antiskate force should be 0.16 g not 1.3 g. Something is wrong.

 

[sergeauckland]

As has been said above, antiskate bias is an approximation, so there's no precise number. However, I prefer to underbias rather than overbias, as with any record that may have some groove damage or pieces of dirt...in other words, all of them...overbiasing will mean that the stylus may skip and stick as the arm will be pulled outwards, whist mild underbiasing means that the arm will stay in the groove once the obstruction is passed.

It is said that a blank disc was the wrong way to set bias, it should be set using a heavily modulated test LP and set for equal mistracking on left or right. Whilst that's probably technically correct, for the reasons above, I prefer to set it using a blank disc and that has worked for me. As long as it still tracks acceptably well, I'm happy to do it that way.

S.

 

[mischa]

If you can use a blank space at the runout section you can also confirm. At that large antskate force, 1.3 g, it should skate outwards when stylus is put down on a blank space. At VTF 1.25 your antiskate force should be 0.16 g not 1.3 g. Something is wrong.

Sorry my mistake.
The Antiscate force is 0,13g not 1,3g.

 

[Balle Clorin]

About cbs str-100 test record from page 52

https://www.worldradiohistory.com/Archive-IRE/60s/Audio/IRE-Transactions-On-Audio-1962-03-04.pdf

And 109 .. calibration data for cbs str-100 test record

https://www.worldradiohistory.com/Archive-IRE/60s/Audio/IRE-Transactions-On-Audio-1962-07-08.pdf

 

[JP]

Good find.

 

[Balle Clorin]

CBS STR-120 OUTER LEFT AND RIGHT

3 DIFFERENT BAND OUTER- center and inner grooves
EDIT added Right channel too

 

[MaxwellsEq]

CBS STR-120 OUTER LEFT AND RIGHT
View attachment 504878

View attachment 504903

3 DIFFERENT BAND OUTER- center and inner grooves
View attachment 504915

Distortion rise is really noticeable for mid as well as inner groove. I'm not shocked at the inner groove distortion (who hasn't experienced it on complex music), but I'm surprised that the mid groove distortion is almost as bad.

 

[EERecordist]

CBS STR-120 OUTER LEFT AND RIGHT
View attachment 504878

View attachment 504903

3 DIFFERENT BAND OUTER- center and inner grooves
View attachment 504915

People like the look of radial arms, but the above graph is why I prefer a linear arm. For today's minimum distortion in electronics, and seeking low distortion speakers as measured by the Klippel, radial tracking distortion is significant.

Tone arm geometry and tracking distortion (longish) - Klaus - Vinyl Asylum

Tone arm geometry and tracking distortion (longish) - Klaus - Vinyl Asylum

www.audioasylum.com

and

Tracing Distortion on Vinyl LPs, Vladan Jovanovic

AES Journal Forum » Tracing Distortion on Vinyl LPs

The AES Forum is where our members get to interact with each other in between conferences and section meetings.

secure.aes.org

 

[Balle Clorin]

People like the look of radial arms, but the above graph is why I prefer a linear arm. For the minimum distortion in electronics, and seeking low distortion speakers as measured by the Klippel, radial tracking distortion is significant.

Tone arm geometry and tracking distortion (longish) - Klaus - Vinyl Asylum

Tone arm geometry and tracking distortion (longish) - Klaus - Vinyl Asylum

www.audioasylum.com

I was surprised too,,,,but I believe it has more to do with radius/wavelength in the groove than tracking error. The tracking error in the outer track is not much worse than the middle track.. Like Korf I do not see the HTA tracking error reflected in any measurements, when measuring distortion across the record.

here is the midway track plot

by the way the AES link is dead. this may work better https://aes2.org/publications/elibrary-page/?id=22236

 

[aaaakkkk]

Comparison of X-talk on test recordings
CA-TRS1007 and Ortofon-TR, depending on SRA.

Body - AT440 MLa
Conical stylus - VM95C (tracking force 2.0 g)
diamond, mounted on 85 SRA



X-talk @1kHz:

CA-TRS1007 85 SRA = L -25.88dB, R -25.59dB
CA-TRS1007 88 SRA = L -24.23dB, R -24.41dB
CA-TRS1007 90 SRA = L -23.15dB, R -23.09dB
CA-TRS1007 92 SRA = L -22.07dB, R -21.9dB

Ortofon-TR 85 SRA = L -26.84dB, R -34.5dB
Ortofon-TR 88 SRA = L -28.85dB, R -37.02dB
Ortofon-TR 90 SRA = L -30.5dB, R -37.98dB
Ortofon-TR 92 SRA = L -37.94dB, R -37.26dB (tracking force 2.9 g)

 

[Balle Clorin]

I think I read somewhere that conical do not care about SRA , so what we see from your with conical test is the probably VTA effect?.. my cheap AT MM ( 3600, 95E, 91R) also seem to have a too low SRA— your photos look very familiar

I find it very difficult to measure the actual VTA since the pivot point is not visible. How do you do it? I used the cantilever angle and compared with your 25.5VTA, then it seems VTA is cantilever angle 21.5C+4=your VTA. it looks kind of reasonable..

 

[Balle Clorin]

Distortion rise is really noticeable for mid as well as inner groove. I'm not shocked at the inner groove distortion (who hasn't experienced it on complex music), but I'm surprised that the mid groove distortion is almost as bad.

R looks more like expectd, crosst talk is a bit unbalanced in outer track , maybe that is som connection with distortion behavior too..

LOW FREQUENY 10-500HZ at-oc9ml2 SME V LEFT AND ROGHT CHANNEL

DENON 51F +Shure V15-IV+Jico SASB with q damping 1.5 and 2.5, same bump at 80-90hz so that is probably from the record itself

 

[aaaakkkk]

I think I read somewhere that conical do not care about SRA , so what we see from your with conical test is the probably VTA effect?.. my cheap AT MM ( 3600, 95E, 91R) also seem to have a too low SRA— your photos look very familiar

I find it very difficult to measure the actual VTA since the pivot point is not visible. How do you do it? I used the cantilever angle and compared with your 25.5VTA, then it seems VTA is cantilever angle 21.5C+4=your VTA. it looks kind of reasonable..
View attachment 505192

I measured the length from the stylus to the pivot point; it's about 2500 pixels. I'll try changing the angle of the stylus relative to the cantilever and take another series of measurements.

 

[Thomas_A]

It is quite time-consuming changing VTA and it sems that large changes are needed to find the minimum for each record. To me it seems that the Ortofon is somwhere between 20-25 degrees but the CA-TRS1007 still a bit of mystery. 15-20 degrees?

 

[aaaakkkk]

I think I read somewhere that conical do not care about SRA , so what we see from your with conical test is the probably VTA effect?.. my cheap AT MM ( 3600, 95E, 91R) also seem to have a too low SRA— your photos look very familiar

I find it very difficult to measure the actual VTA since the pivot point is not visible. How do you do it? I used the cantilever angle and compared with your 25.5VTA, then it seems VTA is cantilever angle 21.5C+4=your VTA. it looks kind of reasonable..
View attachment 505192

I re-glued the stylus. According to my calculations, the SRA is 94 degrees. Is that accurate? How much would you calculate based on this photo?