If you're using an oscilloscope to set azimuth you are well aware of the math hassles involved. First you have to convert the derived voltages into dBVolts then you have to subtract the smaller number from the larger to determine the crosstalk and you have to do it twice: L-R, R-L.
While the name "shaknspin" may sound like a child's toy, the device is anything but, though it does make child's play of measuring turntable speed, calculating wow and flutter, jitter and more, graphically representing speed variations as histograms by frequency and speed distribution and even mo
I once lived on the second floor of an old farmhouse with a springy floor. How it got in my pants, I'll never know! I had a VPI TNT turntable at the time, on a VPI stand that had been filled with leadshot and sand. It was heavy! But the stand still bounced and the 'table's suspension couldn't deal with it and so the stylus bounced around in the groove.
To continue the discussion of whether or not using a USB microscope to set stylus rake angle is a good or bad idea, please look at the drawing accompanying this post.
If you own and use a Fozgometer to set azimuth you must calibrate the unit or your results will not be accurate. I had stopped using my Fozgometer and instead was setting azimuth using a digital oscilloscope, which is 100% accurate and also gives you precise crosstalk voltages.
The stylus rake angle is the angle the stylus’s “contact patch” makes to the record surface. If you have a relatively inexpensive cartridge with a spherical stylus you don’t have to worry about SRA because the contact area remains the same regardless of arm height. On the other hand, elliptical styli along with the more severe “line contact,” Shibata, Geiger, Ortofon and other long, narrow contact patch “cutting edge” (poor metaphor!) stylus profiles require careful SRA setting to perform as designed.
Obviously those lucky enough to own a $6000 tonearm are few, but we don't discriminate here against the 1%. So if you own a 4 Point and over time as you've switched headshells to use different cartridges, perhaps you've accidentally pulled out from the arm tube opening the tonearm wire so you now have excess.
The animated graphic here is taken from the DVD "21st Century Vinyl: Michael Fremer's Practical Guide to Turntable Set-up". The gauge is similar to the kind supplied by Pro-Ject and other turntable manufacturers. It's accuracy is predicated upon the correct pivot-to-spindle for the particular tonearm.
I just spoke with Soundsmith's Peter Ledermann. He confirmed that the contact patch is as seen in the above photo. But note that this is with VTF of zero. He made a few observations about this discussion we're having here on Analogplanet.com.
Vinyl fans tend to be obsessive (no news here!). So when you properly install a new cartridge and after the initial break-in, there's a period of calm and satisfaction knowing the stylus is fresh, the sound is spectacular and your records will be well cared for.
How did this one get neglected? Take a look at the photo supplied by WAM engineering. It shows a stylus in a cantilever. Notice it has been affixed into the cantilever at an angle instead of being parallel to the cantilever. If you use the cantilever to set the zenith angle on this cartridge, which is what I and everyone else recommends, the stylus will not be tangential to the grooves at the null points though it might accidentally be so somewhere else.
"Azimuth" is generally defined as the perpendicularity of the cantilever to the record surface. Some tonearms, including most (but not all) gimbaled tonearms (ones with fixed bearings like Rega and fixed head shell SME's don't allow you to adjust that parameter. You are at the mercy of the cartridge manufacturer, but that doesn't mean you shouldn't check your cartridge's performance even if you can't adjust it.