When using arc tractor, ideally the VTA should be set up exactly as you have it set up with your favorite record. Any discrepancy will add some level of distortion. This is illustrated in the link below. http://cgim.audiogon.com/cgi-bin/vs.pl?vdone&1206403705&viewitem&o24 |
In case anybody wonders how I got the offset number: I modeled a hypothetical tonearm of 240mm in effective length. I marked a point where the stylus meets the record with the VTA being horizontal to the record plane. Another plane was added, which is 1mm higher than the original setup. This new plane represents a thicker record. I then measured the vertical projection of the stylus sitting on the plane that is 1mm higher. The overhand is now longer by 0.032485mm without VTA correction. I don't know how relevant this number is in reference to distortion. This offset probably won't affect the sound much, but it will increase as the VTA increases or decreases from the original overhand setup using the arc protractor. There is an excel file in this link at the bottom of the page. One can use it to verify distortion in reference to overhang. http://www.enjoythemusic.com/freestuff.htm |
