VTA or SRA?


#1

Like I’m sure many of you, I’ve become aware of “stylus rake angle” (SRA) as an improvement of the venerable measurement of VTA as promoted by Michael Fremer.

https://www.analogplanet.com/content/how-use-usb-digital-microscope-set-92-degree-stylus-rake-angle-sra

I’ve done some experimenting with it using the macro lens of my Olympus mirrorless camera and I must say I’m not overly impressed. Fremer recommends an optimal SRA of 92 degrees to mimic the angle of the record lathe while cutting. I find SRA to be frought with measurement error. You have to get the USB microspcope/camera exactly perpendicular to the cartridge which is a little tricky. Then you have to make sure that the scope/camera is perfectly level, which is a hassle. Third, your line of sight has to be exactly level with the tip of the stylus. Furthermore, it’s very hard to get styli with eccentric contact zones measured correctly. I have two carts and both have irregular stylus contact points in the Shibata stylus of the Ortufon 2M Black and contact line stylus of the Soundsmith Zephyr MIMC Star. Plus, the SRA changes as the record plays (increased friction flattens cantilever and SRA) so a static measurement isn’t a real world scenario, honestly. Now I just get the cart and tonearm level using a spirit level and then drop the tail of the cart a couple degrees and then use a couple tracks with a lot of treble to adjust by raising the tail until it sounds right. For reference I’ll check with digital files that are EQ’d closely to the vinyl. I find this method superior to trying to do this by means of SRA. Maybe I would benefit from a USB microscope to do this more accurately, but I don’t want to spend the $200 necessary to get a decent one. What are you guys experiences with this??


#2

I adjust the VTA on my VPI by judging the angle between the arm and the surface of the record and fine tuning that by ear. Since every LP is different, I’m not going to spend more that an few seconds fiddling with VTA.

If you get a ‘scope, consider prioritizing the ability to examine you stylus’ diamond for wear over the ease of measuring the constantly changing angle of stylus.


#3

What I don’t understand, and I may lose my audiophile membership card for asking this.

How can they be two separate measurements? I mean when you adjust the Vertical Tracking Angle, doesn’t that change the SRA? I have read enough Fremer reviews to know they are supposedly two separate adjustments, but can’t understand how you can do them both. I set up my cartridge, before I was aware of SRA, and with my arm I am not aware of any azimuth adjustment. I do know azimuth has nothing to do with my question. I have messed around with anti-skate to balance the channels, as I remember from past cartridges that the setting does not always match up with tracking weight.

When it comes to setting up arms and cartridges, I don’t have all that much experience. I have only owned 6 tables in 47 years, and one I had for less than a month.

Can someone explain how you do both VTA and SRA?

Let me know where to turn in my card, he said feeling quite bashful and humbled.


#4

IMG_2985.JPGI wouldn’t worry about VTA. Here’s a link to SRA & VTA on tnt

TNT

this picture is from the article.

Even setting the ‘correct’ SRA can be a challenge.

IMG_2984.JPG