Fun with vinyl measurements

[Balle Clorin]

A fresh crosstalk/azimuth investigation today as I explore AnalogMagic V1, yes the -53db is true, I got repeatable values around -50db
I am using a Michell Clamp, it comes with a felt pad to put under the record around the spindle
Cartridge is Shure V15-iv with Jico SAS B, Azimuth set by Toshiba record 36/36

Spoiler: details

Toshiba track is 440Hz and too short for AM to analyse, but the crosstalk can be found form the plot values mV

 

[morillon]

signal at what level on analogmagick?

 

[Balle Clorin]

AM reports with Puffin Digital out to PC : AP Ultimate analog 127mV, Ortofon 118mV, AM 172mV rms all at 39db RIAA gain

 

[morillon]

annconced at ?cm/s
seem important...
impact your results....

 

[USER]

Yes. Always a bit difficult to do perfect but this is at least one try.

View attachment 416956
View attachment 416957

Nice measurements. I too have not noticed much of a difference when it comes to VTA adjustments and FR. If you guys can come up with any lessons learned (or questions/experiments to investigate further) let me know and I'll add a section to the measurement library user guide on page 1.

 

[JP]

 

[Balle Clorin]

annconced at ?cm/s
seem important...
impact your results....

No cm/s given, you can back calculate it maybe from AP Ultimate disc info

 

[JP]

Nice measurements. I too have not noticed much of a difference when it comes to VTA adjustments and FR. If you guys can come up with any lessons learned (or questions/experiments to investigate further) let me know and I'll add a section to the measurement library user guide on page 1.

For relationship to FR you'd likely need to look at inner grooves and line contact types with larger minor radii, but you're really talking about geometric issues akin to IGD (as a family). Seems distortion is where it'd be, but better investigated with spots than sweeps; for a 20-20k log sweep, 10kHz is present for about 0.1s, and 20kHz for about 0.05s. We can see larger distortion trends, but minute stuff would be a real chore.

 

[Balle Clorin]

from memory, on hungaroton, and at155.."41/41" but on a 8cm (35 with denon "1k ref" but must be a 5 or 3.54cm to check)

Ultimate Analog …you do the math

Cartridge gives 2.65mV at 7cm/s UA track above

 

[Thomas_A]

For relationship to FR you'd likely need to look at inner grooves and line contact types with larger minor radii, but you're really talking about geometric issues akin to IGD (as a family). Seems distortion is where it'd be, but better investigated with spots than sweeps; for a 20-20k log sweep, 10kHz is present for about 0.1s, and 20kHz for about 0.05s. We can see larger distortion trends, but minute stuff would be a real chore.

Are there any test records with high level HF test signals at inner grooves?

 

[rwortman]

So where are the great frequently change everybody is talking about when changing arm angle VTA? … more bass more treble …

Always seemed like BS to me. Hugely audible change from .1 degree change in VTA. Yea, sure. Probably need to have THC enhanced hearing.

 

[Balle Clorin]

Somethings change with VTA , I played with AnalogMagik VTA test track today, and managed to get IMD distortion from 3 to less than 1.5% . I simply removed my 2mm platter mat ( Michell Gyro are supposed to run without mat) , I further optimised by increased VTF from 1.25 to 1.5 gram. Low VTF gives better crosstalk but higher distortion in the AM VTF track , anyway recommend range is 1.25-1.75g

The AM software can interpret the VTA track on AP Ultimate Analog test record too… there I got less response but IMD went from 2.5% to 2.3% ..the VTA change was 2mm lower at the stylus.

I have yet to listen for the effects

AM is actually a useful toy

 

[morillon]

it is the use of MI of virtins...
it was just made for analogmajik a w&f module (which for obvious commercial reasons is only on the most expensive version of MI) ....
but a function now present on multitones, very adapted for such a function... no longer of interest "in real life", especially since we can couple to the approach via gyro and telephone also an interesting approach "without the limits" of the disk...
or the specific software python from here... ;-)

 

[JP]

Somethings change with VTA , I played with AnalogMagik VTA test track today, and managed to get IMD distortion from 3 to less than 1.5% . I simply removed my 2mm platter mat ( Michell Gyro are supposed to run without mat) , I further optimised by increased VTF from 1.25 to 1.5 gram. Low VTF gives better crosstalk but higher distortion in the AM VTF track , anyway recommend range is 1.25-1.75g

The AM software can interpret the VTA track on AP Ultimate Analog test record too… there I got less response but IMD went from 2.5% to 2.3% ..the VTA change was 2mm lower at the stylus.

I have yet to listen for the effects

AM is actually a useful toy

Maybe. You changed several things at the same time.

 

[Balle Clorin]

Kind of consistent.. Removing platter mat = increase VTA by +2mm (0.5degree) reduces %IMD within VTF range

NExt is a sweep check . RED= +2MM VTA at 1.5g VTF. Conclusion +2mmVTA (platter mat removed) top end of L&R seem better balanced, but Azimuth / slightly crosstalk worse..
LEFt VS LEFT, Somewhat LOWER TOP END

Right channel comparison

+2MM VTA L and R

Reference VTA (with patter mat)

 

[Thomas_A]

Somethings change with VTA , I played with AnalogMagik VTA test track today, and managed to get IMD distortion from 3 to less than 1.5% . I simply removed my 2mm platter mat ( Michell Gyro are supposed to run without mat) , I further optimised by increased VTF from 1.25 to 1.5 gram. Low VTF gives better crosstalk but higher distortion in the AM VTF track , anyway recommend range is 1.25-1.75g

The AM software can interpret the VTA track on AP Ultimate Analog test record too… there I got less response but IMD went from 2.5% to 2.3% ..the VTA change was 2mm lower at the stylus.

I have yet to listen for the effects

AM is actually a useful toy

How does it interpret the AP record lateral IMD test?

 

[Balle Clorin]

Cannot see any lateral Test on AP, the AP VTA test is stereo.
hard to see any clear response to 2mm VTA change

But AP Ultimate prefers +2mm VTA ( no platter mat for crosstalk/Azimuth)

 

[Thomas_A]

Cannot see any lateral Test on AP, the AP VTA test is stereo.
hard to see any clear response to 2mm VTA change
View attachment 418059

It should not give any clear results for VTA though since it is not cut that way.

 

[Balle Clorin]

Ultimate Analog is cut stereo IMD same as Analog Magik but 60/4000 not 60/7000 as AM that is why IMD result with AM software on Ultimate fails

 

[Thomas_A]

The VTA - VTF relationship. I've been in a discussion on SHF regarding dynamic VTF, and wonder what you say about the following:

A typical cantilever is 6 mm long and if 20° VTA, loaded with 20 mN, and compliance of 20 µm/mN will give a VTA decrease of ≈1° during average drag. This means that the corresponding yield of stylus height to record surface at headshell/stylus pivot goes from 2.05 to 1.95 mm, i.e. 100 µm, corresponding to an increased load of 5 mN or 0.5 g.

Correct calculation? If so, quite much.