Here's a write up by Jon Risch on VTA/SRA. I only wish I could find the picture that makes this all obvious. Basically the pointy sidewall of the Shibata stylus as to align perfectly with the angle of the cut in the record groove. Listen to high frequency tones for this, like triangles and vibes. When that aligns properly all should lock in, including the bass.
"Getting the stylus contact line to line up with the HF modulations of the groove wall is similar to aligning a tape haed to the recorded waves on the magnetic tape: you want them to be totally parallel with one another. When a fine line stylus is not aligned with the groove wall in terms of matching the SRA to the record walls groove angle as cut by the cutting stylus, then the footprint of the stylus will be riding over more than a single HF groove wiggle at a time. This results in a loss of HF's, and a blurring in time of the recovered signal, just like on a tape deck. If that was all that occurred, then incorrect SRA would be rather benign.
However, the situation for the groove wall is not like that of the tape deck, the groove wall and stylus are a mechanical interface whereby the groove wall modulations can torque on the stylus edge as it passes over the modulations at a rake angle that is not the same. This tends to generate spurious signals that are not harmonically related to the original signal, and the torquing tends to cause the intrisnic cartridge cantilever/moving system resonances to be excited and stimulated. The result: hash and HF frazzle that reaches surprisingly low in the audio band due to intermodulation with the signals being recovered from the record groove."
"Getting the stylus contact line to line up with the HF modulations of the groove wall is similar to aligning a tape haed to the recorded waves on the magnetic tape: you want them to be totally parallel with one another. When a fine line stylus is not aligned with the groove wall in terms of matching the SRA to the record walls groove angle as cut by the cutting stylus, then the footprint of the stylus will be riding over more than a single HF groove wiggle at a time. This results in a loss of HF's, and a blurring in time of the recovered signal, just like on a tape deck. If that was all that occurred, then incorrect SRA would be rather benign.
However, the situation for the groove wall is not like that of the tape deck, the groove wall and stylus are a mechanical interface whereby the groove wall modulations can torque on the stylus edge as it passes over the modulations at a rake angle that is not the same. This tends to generate spurious signals that are not harmonically related to the original signal, and the torquing tends to cause the intrisnic cartridge cantilever/moving system resonances to be excited and stimulated. The result: hash and HF frazzle that reaches surprisingly low in the audio band due to intermodulation with the signals being recovered from the record groove."