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arnoldc wrote:I found this formula from the Roy Gandi, maker of Rega.
0.5/9 ≈ 0.055 ≈ sin(3°)
So, the 0.5" change I mentioned in my previous post will alter the VTA (not SRA) by 3°
But I'm faced with another mathematical problem- if the VTA was altered 3°, what will be the change in SRA?
This does not address my question still...
ps.
9 in the formula above means a 9" tonearm
arnoldc wrote:No. And that is the most common misconception. That's why definition of the SRA and VTA must be clearly understood.
To be clear, check this out from The Analog Depot
Hyperion wrote:Assuming a perfectly stiff cantilever (like a diamond cantilever) and stylus, the relationship is pretty linear since the angle between the cantilever and the stylus (90° + VTA - if the stylus is perpendicular to the record) will always remain the same, i.e. increasing/decreasing the VTA will result into a similar corresponding degree of change in SRA. However reality is not so simple because of cantilever flex (and some of them arent even straight ... ) and usually because the stylus is much stiffer than the cantilever making the relationship non-linear. Still I think it would be safe to assume that the change in SRA will be quite close to the change in VTA.
For stylus perpendicular to record: SRA = 0. SRA = delta VTA.
For stylus less than perpendicular to record: negative SRA. SRA = negative initial SRA + delta VTA (subtraction)
For stylus more than perpendicular to record, SRA = positive initial SRA + delta VTA (addition)
In fact the relationship is exactly: New SRA = Initial SRA + delta VTA
1. That lifting your tone arm's arse will change the VTF, the opposite is not true.
arnoldc wrote:conspicuous, the lateral frequency is the point where your cartridge get excited and vibrates from left to right. The vertical frequency is the point where you cartridge gets excited (literally) and it jumps up and down frantic fashion.
BenC wrote:Hi All,
Just for clarification, if the SRA per the borrowed diagram from t-n-t is more than 90 degrees, is this what we call NEGATIVE SRA? ... Less than 90 degrees, POSITIVE SRA? Thanks!
BenC
zetroce wrote:arnoldc wrote:No. And that is the most common misconception. That's why definition of the SRA and VTA must be clearly understood.
To be clear, check this out from The Analog Depot
Hi Arnold,
The way i understand it is that SRA and VTA are using 2 different points of reference and will have different initial settings. But if we are talking about the angle difference ( delta ) if you may call it, in VTA and SRA as you adjust the armtube and tilt it downwards or upwards, the value should be the same, regardless if your reference is the vertical or horizontal plane.
Tama ba?
conspicuous wrote:arnoldc wrote:conspicuous, the lateral frequency is the point where your cartridge get excited and vibrates from left to right. The vertical frequency is the point where you cartridge gets excited (literally) and it jumps up and down frantic fashion.
arnold, rod (audiophileman2002) - thank you for explaining this. thanks too for this discussion as i, and others i'm sure, am learning more about analog. so far it looks like trigonometry will suffice without having to go into differential equations yet
from the equations for lateral freq i can then deduce that the infamous "grado dance" is due to the relatively high compliance of the cantilever. or is it the other way around? if the cantilever is too stiff (low compliance) then it has a tendency to be excited to do the dance? (the grado dance describes the cartridge vibrating unwantedly from side to side at certain times)
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