Pivot to Spindle distance

Lofgren and Baerwald published their papers on tonearm alignment in around 1940, when the only records were made of something other than vinyl and all were mono 78s. And most people still owned wind-up Victrolas with megaphone speakers.

Elliot, In the end, it's effective length that counts, along with headshell offset angle.  Since effective length is the sum of P2S + overhang, since different designs feature different headshell offset angles, and since there are at least 3 different commonly used geometries that all result in two null points on the surface of the LP (and actually a myriad of such solutions that just haven't been associated with the names Stevenson, Baerwald, or Lofgren), there are many "solutions" to the problem.  Depends where you want to place the two null points (closer to the spindle or closer to the outermost grooves, for example) and how much tracking angle error you are willing to tolerate when the stylus is NOT on a null point.  And I am as bored as anyone else with this topic.

fsonicsmith, I admit to being overly inquisitive at times, in my search for clarity, but on this thread, all I asked for was the OP to explain the very vague term he used to indicate he was satisfied with his alignment despite the known 5mm error in P2S ("pretty good"). I am an alignment nihilist, almost like MC, but I do make the effort to get it right, once. After that, I just listen. Like the OP, I have had the experience of accidentally discovering after the fact (and after listening to LPs for hours and hours) that I made an error in P2S distance. On that occasion, I fixed the problem and thereafter could hear no increase in my already high level of listening pleasure, compared to the hours I had spent with the misalignment. But I felt better.

To MC’s point, how many posts do we see where some guy describes a mysterious problem with his phono SQ? Those posts are almost invariably followed by suggestions that he check his alignment parameters. This is evidence that most of us are true believers. Conversely, when said complainant goes off stage and "fixes" his alignment, he almost invariably comes back to us to say how wonderful his LPs now sound, thanks to his having tweaked his alignment. I don’t know whether this is evidence for or against MC’s hypothesis. As you know, I am a big believer in subconscious bias that affects our listening.

Mark, You wrote, "My P2S distance is off by about 5 mm (over). But my cartridge seams to be aligned pretty good."  Define "pretty good".  Thanks.