Triplanar Problem

Doug, you wrote, "2.a. that adjustment beneath the VTA tower was mis-set by the manufacturer or altered by somebody. This is a job for Tri-Mai unless you're feeling brave. There's only one correct position and it's unclear to me (doing this from memory) how to measure or describe it. Even rotating to the correct spindle-to-pivot dimension might be wrong, if 2.b were also off."

I agree that there is only one correct position, but the qualification is that there is only one correct position for a given set of three mounting screw holes. Swinging the arm pivot with respect to the VTA tower could be corrected for by drilling a new set of mounting screw holes. I almost had to mess with that screw under the tower myself, because the lucite jig that Tri sold me was slightly inaccurate. (As you say, Tri told me NOT to do it.) I found that my older metal jig, that locates the tonearm by fixing the location of the pivot point, was more accurate. Anyway, I don't see why or how one could ruin the tonearm by rotating the VTA tower, but it's not for the faint of heart to do that. By the way, measuring twice with an inaccurate mounting jig will not help much.

I think there may be too much play in the lucite jig, especially when the tonearm mounting platform is significantly below the plane of the platter/spindle. Anyway, that seemed to be the source of the inaccuracy of my jig. Sorry if I was redundant; I do see your point.

Thankfully, Tri can still supply the metal one, originally designed and supplied by Herb Papier, which locates the tonearm via the spindle to pivot distance directly (at least Tri was able to send me one, after I lost mine). That's probably the one to use.

Thom et al, Since I am thinking of re-mounting my Triplanar on a new tt, I have just re-read this thread. I came to Thom's post, where he says the following: "My point is that even the metal jig should not be trusted, because of sample to sample variance in the mounting flange's orientation." The metal jig that I own has at one end a tiny spring-loaded inverted cup that fits over the bearing screw, right at the pivot point, and at the other end it has a hole that fits over the spindle. It would seem to me that this device eliminates any issues related to the variation in the orientation of the mounting flange. All one needs to verify is that the distance between the geometrical center of the cup at one end and the spindle hole at the other end is equal to 233.5mm (which I surely plan to do). What am I missing?

Yes, I agree it is difficult to locate all 3 holes at once and then position the arm as one would like it. In fact, I am skeptical that I can do the setup within 0.5mm error, but I will certainly try. Having a little play in the screw holes helps, I guess, to get it right at the end. FWIW, the metal jig I describe above was sold to me by Tri, because I lost the original one that was once made by Herb Papier and supplied with every tonearm he sold.