Why do it at all? Because a conventional 8.5" or 9" tonearm can have a tracking error up to 3 degrees compared to the linear arm error of less than 0.5 degree. So the "gimmick" would be to lower harmonic distortion. As for the comment on servo damping, dan_ed makes it sound more complicated than it is. The tonearm, cart/stylus, LP groove form a sytem which will resonate at one particular frequency which is variable. Detection of resonance is easy and almost instantaneous due to a very large increase in amplitude. With the servo detecting and changiing some variable, it keeps the sytem away from the resonance point. Theoretically, it should produce cleaner sound.
Servo Controlled Arm
I've purchased a JVC QL-Y3F Turntable )bought originaly in 1983) with servo controlled arm. As I've been reading about tonearms and compliance it has made me curious why the servo controlled arm didn't catch on. I have a Denon DL160 cartridge and it hasn’t even considered skipping. Now that I've listened for a considerable length of time I'm curious what other people have to say.
Sincerely,
Sincerely,