Servo Controlled Arm

What is the microprocessor, and the servo system, using for sensor feedback? It has to know where it is in the groove at all times. I'm betting the sensor I'm looking for is the stylus which is then sending minute pressure changes, most likely to an A/D, then into the microprocessor. Yes, it is hunting/reacting constantly even if it isn't audible.

At some level the hardware or programmer implements some kind of thresholding on both the lower and upper bounds. (You never want the arm to suddenly jump across the room. ;-)) In the mean time the stylus is plowing along hitting the snow banks on both sides just like a snow plow. All that has been accomplished is digitized following, not tracking.

I'm not saying it can't sound good, maybe very good. I just don't see the need to complicate something as simple as tracing a groove when there are several tonearms available today that have exceptional bearings, that can be set up repeatably and don't need the help to track most any grove. I'll just remain optimistic, but skeptical.

BTW, I'm proud to say I'm not an audiophile. :-)

I have my suspicions about this approach. The easiest way to "break" this concept is to put on an LP that is not perfectly centered. Each time the eccentricity comes around the stylus gets slammed from one side to the other because the servo cannot react properly. Now it may very well play perfectly pressed LPs beyond amazement, but the design does seem to limit what LPs could be enjoyed.

What arm would that be? I don't know of any arm that doesn't self correct based on stylus position in the groove. Granted, some may do it better than others.

If I want to go down stream in a kayak, do I handle the paddle myself? Or do I through a line to two friends, one on either side of the river, and have them steer my kayak for me?

IMHO, of course. :-)

Again, why do it at all? I would file this under "gimmick". That's all I'm saying.

I do understand those points, but it is still constantly hunting for the correct groove position based on reaction to what has already occurred. I just don't understand the "why do it at all". Perhaps there are others, but the only reason I can think of is that the designers have made the assumption that no conventional arm can track as well as this feedback control servo mechanism.