Fun with vinyl measurements

[Thomas_A]

Which one do you mean ?The Sperling or Clearaudio?

Sperling

 

[Balle Clorin]

Very curious what inter channel phase difference you get. I cannot get below max deviation of - 2 . And I cannot adjust my cartridge more . I need to set up my experiment TT with my AT VM540ML

 

[Thomas_A]

Very curious what inter channel phase difference you get. I cannot get below max deviation of - 2 . And I cannot adjust my cartridge more .

Yep. I want to cross-correlate that to the CA-TRS1007. If you record the first 1 kHz pilot tone of CA-TRS1007 what do you get?

 

[Balle Clorin]

CA TRS-1007 and my Sperling is in the same ball park..here compared with your data on CA TRS-1007. Not sur why my OC9ML2 is so far off, does not look bad in microscope...Maybe the fact that it goes though a SUT has an effect?

Ultimate analog phase diff:

finlally a single L&R 70uS test pulse from Toshiba record

 

[Thomas_A]

Odd. Is the arm mounting distance pivot to platter center perfect as well?

 

[Balle Clorin]

Tried to shift the SME V sledge back and forth- changing pivot-spindle change-,, about 4 steps of 4mm each.. best result with almost max overhang/ minimum pivot-spindle which is clearly off from both SME aligment tool and a normal protractor.

I THINK i made the correct conversion from phase diff to HTA error, AI agreed with me , but I am not sure

 

[Thomas_A]

Hm. I remeasured mine today since I've fiddled with a new better shim. Now goes from +0.4 to about -0.4°, there is a slight turn counter-clockwise in the headshell. I should perhaps increase antiskate a tiny bit, it does seem to correlate with the distortion graph.

 

[Thomas_A]

Check the SUT perhaps. Would not suspect it but you never know. Still suspect the stylus. Not easy to get the contact facets clear on a photo.

 

[Thomas_A]

@Balle Clorin,

is your arm pivot to platter center 215.35 mm? Just checking.

 

[Balle Clorin]

Just now 214mm , but tried variation 210-225 without success, SME spec is 215.35 for 9.5mm from stylus tip to mounting holes

 

[Thomas_A]

Just now 214mm , but tried variation 210-225 without success, SME spec is 215.35 for 9.5mm from stylus tip to mounting holes

I am out of ideas. Something is off though.

 

[Balle Clorin]

Even stranger the SUT is in bypass mode . Have to experiment a different system to see how system respond to more dramatic changes

 

[Thomas_A]

Even stranger the SUT is in bypass mode . Have to experiment a different system to how system respond

I can only think of zenith error.

By the way, I think Wallytools may be right regarding zenith correction. Ater twisting the cartridge to reduce zenith there may be a bit of more detail and coherence to the sound, less smearing. All subjective of course. Systematic testing for it would be quite exhaustive.

 

[ElectricWarrior]

Just now 214mm , but tried variation 210-225 without success, SME spec is 215.35 for 9.5mm from stylus tip to mounting holes

what's your effective length?

 

[Balle Clorin]

233.15 if I recall correctly ,SME V

 

[ElectricWarrior]

233.15 if I recall correctly ,SME V

that's what they specify. If you knew the actual effective length you could calculate the correct mounting distance.

 

[Balle Clorin]

Audio Technica ATOC9MLii stylus distance 8.75mm stationary. Maybe 9mm spinning? VS SME V that is based on 9.5mm mounting hole to tip distance. So I am about 0.5-0.7 mm less than the 233.15 spec effective length.

 

[ElectricWarrior]

With your effective length being approximately 232.65 mm, you need 214.82 mm pivot to spindle distance and 17.83 mm overhang to reach the Löfgren A null points. It's funny that it would require so much more overhang.

The pencil leads look misaligned on the outer null, too..

 

[Thomas_A]

Played around with the Sperling record yesterday, will continue today and report. First impression is that my original geometry seems basically correct (curve shape) but there is a need for zenith correction. It was a bit of a pain to correct it though; and I am on the learning curve for very very fine adjustments.

 

[morillon]

With your effective length being approximately 232.65 mm, you need 214.82 mm pivot to spindle distance and 17.83 mm overhang to reach the Löfgren A null points. It's funny that it would require so much more overhang.

The pencil leads look misaligned on the outer null, too..

Just a quick reminder, among all the adjustments, protraction on our pivoting arms is one of the most relative... ultra-precision to a tenth of a millimeter, or even a millimeter, is laughable...
It's quite fundamental not to forget that...
;-)