Thank you all for the answers, but so far no one have answered directly my question: If I adjusted the VTA by 1 degree, will the SRA change with the same 1 degree?
Thanks
Since I muddled this one up the other day let me clear it up now. The answer is yes- sort of.
VTA generally refers to the angle of the tone arm, although technically it is the angle of the cantilever. Almost always when people say VTA they’re talking about the tone arm. Since the cartridge is fixed in the arm and the arm base is what is adjusted it gets real technical splitting hairs between the two.
SRA Stylus Rake Angle is the angle of the stylus to the record. The idea is to have the angle of the stylus match the angle of the cutter that was just to cut the groove. SRA is the angle that counts.
In a fixed, static, diagrams on paper world if you raise the arm to increase VTA by 1 degree then yes SRA will also change by 1 degree.
The problem is records are cut in an engineering process with a tool similar to the cutting edge on a lathe. The cutter head is powerful and moved back and forth and up and down with great precision.
The way we play them back is a completely different thing altogether. Unlike the cutter head that is held in the same alignment the stylus is at the end of a cantilever that is free to wiggle around in some rubbery donut, at the end of a long arm that is free to move up and down and left and right and this whole contraption is bouncing around all over the place.
The way it works, because of the way its balanced, if you dig into it real close the 1 degree does not translate into 1 degree because the cantilever moves based on VTF and VTF is set at one angle so when the angle changes the VTF changes and this in turn changes the SRA. Not much, hardly any. The point is to understand the Rube Goldberg imprecise wobbly nature of the thing.
Then totally aside from VTF (and warped records) the SRA is still never gonna stay where its set because this whole thing is always moving. Playing a record the groove modulates and this drags on the stylus pulling the cantilever and changing SRA. These angles are simply constantly changing all over the place all the time no matter how carefully aligned or what you do.
Its even worse than this. The stylus doesn’t even trace the groove. Oh sometimes it does. But a lot of the time its bouncing from one spot to another sort of sampling the groove. This is because the groove puts so much energy into the stylus, it travels up the cantilever, reflects back down, and the stylus being the least massive part of the whole thing is like the end of a whip.
The point of my incredibly long-winded dissertation is to drive home the hopelessness of trying to align a cartridge by obsessing on such matters. Its not that they’re a total waste of time. They are, and they aren’t. They are in the sense they get you in the ballpark. They aren’t in that you still need to find your seat.
The one and only way of doing that is by ear. Listening by ear you will be able to hear which is better. How many degrees that is, who cares? The differences we are talking about here are not measured in degrees. They are not measured in arc-seconds. They are not even measured by micrometers.
How could they be? The smallest undulations on a groove are on the order of the size of some large organic molecules. Tracing such incomprehensibly small undulations with a stylus that on that scale looks like a boulder, and a boulder bouncing from wall to wall to boot, is as Peter Ledermann loves to say something that should not work.
Yet it works phenomenally well. Especially when tweaked to perfection by ear.
