Pickup SRA - starting from a 500x microscope


I am not sure if my Lyra Atlas has the right SRA. Can other owners contribute? I have bought a 500x usb microscope, but it remains hard to find the exact angle. It is easy to get the angle of the record (or platter - I use a mirror), but very hard to get the angle of the stylus. I use the Cooling Tech software but it does not solve my problems. Trying to estimate the angle I cannot set the crosses sufficiently exact, and end up with values like 88, 90, 94 - varying all over the place.
I have only taken a few pictures so far, and could perhaps improve them. Tips and info welcome.
Ag insider logo xs@2xo_holter
Thank you, JCarr, much appreciated. Ever since I bought my first Lyra, a Clavis, I have adjusted by ear, and your text confirms that this is (still) the main way to go. Happily the microscope wasn't a big investment. Obviously, some find it useful, including Michael Fremer. I wasn't aware of the strong feelings (or obsessions) in this area. Now, I will go back to my traditional method. All measures set as suggested in the Atlas instructions. Then, lights off, on with some favorite music. Listen, try a tiny bit up, listen again, a tiny bit down, etc. When I no longer think about it, because the music grips me - thats where it stays. If I end up with a weird SRA, OK, I'll let you know!
Hi Ralph: No, I missed that post of yours, but it is a good one. Much of my knowledge of the LP cutting process comes from Takawa-san and his boys who were responsible for all of the King Super Analog series, and also Joe Harley, who has produced many a LP, but it is nice to be able to check my information against yours.

Guys, Ralph owns and operates an LP cutting lathe, and when he writes something about LPs and the LP mastering and cutting process, his words are based on first-hand experience!

BTW, I have absolutely no desire to dissuade anyone from using a USB microscope. As a firm believer in the importance of correlating objective measurements with subjective listening impressions (or at least seriously trying), I strongly encourage the use of azimuth checkers, digital scales, USB microscopes and anything else which can attach numbers to what we hear.

My prime suggestion in this case is that the ear be used as the principle guide, and the microscope used to translate the optimal setting into numbers that can be replicated or independently confirmed.

I'd love to see a database containing the SRA findings of hundreds of audiophiles. The greater the number of SRA reports, the more the outlier cases will be down-prioritized, leading to more meaningful results for us cartridge manufacturers. It would also be nice to have cantilever rake angles (which the microscope software should be able to supply) as well as the SRA, since the cantilever rake angle must also affect how the cartridge responds to the LP groove (as I wrote in my previous post).

kind regards to all, jonathan
Some months ago an audo friend of mine, visiting and listening to my system, adjusted my SME V arm upwards - he felt that the Atlas sounded better that way. It went as far up as possible, 6-8 mm in my case (Hanss T30 player). I thought, well perhaps he is right, at least it does not sound worse. Today I tried again, adjusting the arm down to parallel, listening, a bit up, listening again, and then up to the highest postion. Well yes, vaguely (my old non-golden ears), once more I did prefer the highest position, quite a bit above parallel. Now, what I should do (before I throw away my microscope), is to take some good pictures. Since my friend borrows it, they will come, later. Perhaps a core matter here, is that the Lyra pickups are made to be fairly - dare I say it - robust regarding VTA/SRA? In a sense, their "goodness" is their own worst enemy? I mean, if any of these adjustments had sounded BAD we would all have heard it, right, including Michael Fremer, who reviewed a lot of equipment with his Lyra Titan FAR TOO LOW on his LPs. I have a Meade telescope. It "clicks into place" when the focus is right. There is no question, one thing is RIGHT, all the rest is WRONG. My impression of Lyra pickups, unless you are really out of tune, there is seldom a WRONG, there is only a QUITE GOOD. And this often sounds mighty good too. So I am not sure if the "click into place" applies. Although I do believe in getting the best possible - going most of the way.
Hi O_holter. When you raise the SME pivot by 6-8mm, you are not only changing the SRA, you are also increasing the VTF, and reducing the overhang along with the tonearm effective length.

In order to isolate your findings to SRA only, you need to compare the VTF before and after raise and add the difference in VTF to the before raise position, or subtract the difference in VTF from the after raise position.

Also, you need to quantify how much the stylus position has moved and either pull the Atlas back a skosh in the before raise position, or nudge it forward a skosh in the after raise position.

I am not poo-poohing your findings at all, but good science demands that only one variable is changed at a time - even though you will have to fight the tonearm design to accomplish this.

Once you have confirmed the above and hopefully pinned the reason for the sonic improvement down to SRA increase and nothing else, I would be very interested in knowing what SRA and CRA (cantilever rake angle) your USB microscope reveals.

kind regards, jonathan