Doug, I'll take that remark as a compliment? (unless informed otherwise.) Actually, this thread was partly inspired by the beautiful stylus pics you posted, plus people keep asking me how to do this. I know you adjust your SRA a lot, and I wish I could too, but the SME V was apparently designed in the "set it and forget it" days. I keep mine at 1.4 degrees which seems to work well for most recordings, but if anyone out there has an xtra Tri Planar for sale cheap, I'd be interested ;~))
Dan, I don't blame you for asking. It's quite simple really, and just a matter of geometry as you will see. Unfortunately, it would be a lot easier to draw it for you, but I'll try and explain it in words first, and maybe later I'll have time to make a diagram and post it. So please leave a post to let me know if the following makes sense to you:
A typical 9 inch TA measures 23 cm (or 230 mm) from the vertical bearing to the stylus tip. Imagine now that you lift your TA with the finger lift, but instead of setting it on the record, you just keep lifting it (magically of course) up and over the back of the turntable base, and continue under and up through the base to the armrest again.
OK? So you've just made a circle with the stylus tip; so far so good? The length of this circle's circumference (in millimeters) is PI times the diameter of the circle. The radius of the circle is 230 mm (the TA length) so the diameter is 460 mm. PI is 3.1416, so PI x 460 = 1445 mm (the length of the circumference traced by the stylus).
There are 360 degrees in a circle. So each (pie-shaped) degree of our circle would contain one three-hundred-and-sixty-eth of that 1445 mm circumference. Divide 1445 mm by 360 = 4 mm.
So if you raise the stylus end, OR THE BEARING END (which is what we need to do to create SRA at the stylus end) you are going to tilt the tonearm AND THE STYLUS (which is attached to it) exactly one degree!
If you have a cool tonearm like Doug's Tri Planar, you just dial up however many degrees (times 4mm) you want. If you're stuck with something less accomodating, I've found the best way is to use a stack of automotive feeler gauges to achieve the height you want.
Dan, I don't blame you for asking. It's quite simple really, and just a matter of geometry as you will see. Unfortunately, it would be a lot easier to draw it for you, but I'll try and explain it in words first, and maybe later I'll have time to make a diagram and post it. So please leave a post to let me know if the following makes sense to you:
A typical 9 inch TA measures 23 cm (or 230 mm) from the vertical bearing to the stylus tip. Imagine now that you lift your TA with the finger lift, but instead of setting it on the record, you just keep lifting it (magically of course) up and over the back of the turntable base, and continue under and up through the base to the armrest again.
OK? So you've just made a circle with the stylus tip; so far so good? The length of this circle's circumference (in millimeters) is PI times the diameter of the circle. The radius of the circle is 230 mm (the TA length) so the diameter is 460 mm. PI is 3.1416, so PI x 460 = 1445 mm (the length of the circumference traced by the stylus).
There are 360 degrees in a circle. So each (pie-shaped) degree of our circle would contain one three-hundred-and-sixty-eth of that 1445 mm circumference. Divide 1445 mm by 360 = 4 mm.
So if you raise the stylus end, OR THE BEARING END (which is what we need to do to create SRA at the stylus end) you are going to tilt the tonearm AND THE STYLUS (which is attached to it) exactly one degree!
If you have a cool tonearm like Doug's Tri Planar, you just dial up however many degrees (times 4mm) you want. If you're stuck with something less accomodating, I've found the best way is to use a stack of automotive feeler gauges to achieve the height you want.