Why Linear Tracking never took off?

Willster...Your PS X800 is obviously broken. This happens to the best of equipment after 25 years. How it sounds probably has more to do with the pickup used. Most of the time mine was used with a Shure V15MR, and that particular pickup never sounded, or tracked, better. If you have given up on this TT you should sell it. You might be surprised what they sell for.

I also have the Sony PSX-800 with linear tracking biotracer arm, and find that it performs flawlessly. For example, it will play records so badly warped that an ordinary arm gets tossed completely out of the groove.

The reason that I bought it was because I attended a seminar at a High End audio shop on the subject of how to set up a conventional pivoting arm. I never realized how many angles and tracking forces were involved, and how many of these errors can only be approximately corrected because things change as the arm tracks the record from outside towards the spindle.

I think that most linear tracking arms failed because they relied on virtually frictionless bearings so that the arm would move with a very tiny sideways force from the stylus.
The Sony Biotracer arm uses servo motors to move the arm (side to side and up and down) so as to keep all those troublesome angles down to about 1/10 degree. Stylus downforce is also applied electronically, a nice feature which lets you adjust the force while a record is playing so that the sonic effect can be heard.

Henkaudio...The servo system that moves the arm pivot assembly quickly along the track, lowers the arm at the outer groove and picks it up when the record is finished is separate from the system that controls movement during play. I don't think that cleaning or lubricating the arm track will help, especially since you say that the arm plays OK once it gets going. If you try cleaning the track be careful not to use anything that would leave a sticky residue. I think that your unit may need some adjustment to the fast arm movement servo. Sony service centers (one of two in the USA is near Boston) claim to be able to work on the PSX800...I wouldn't let just anyone try. I have a copy of the service manual and let me tell you this is one complex piece of electromechanical hardware, and software. Yes the thing has several microprocessors in it.

This player is a technical masterpiece (I think they must have sold it at a loss) and I would ship mine back to Japan if necessary to get it fixed. In these days of the global marketplace, shipping to Japan wouldn't be much different from shipping across the USA.

I just fired up the old Sony PSX-800 for a quick listen. The old Shure V15 pickup tracks perfectly over the complete disc at the minimum downforce setting of 0.5 gram. Try that with your SME! If you have a MC pickup tracking at 2.5 grams I guess it doesn't matter.

Also, review of the service manual tells me that the tracking angle error is held within 0.05 degree, not 0.1 as I suggested in my post. That matters for any pickup.

trimmer@nodomain.net...With regard to groove spacing...it not only varies between records, but varies within a record according to the program. Loud music requires wider groove spacing, and for soft music closer grooves are OK. Variable groove spacing makes it possible to get more minutes of music on an LP.
The servo controlled linear tracking system of the Sony PS-X800 varies the arm movement speed so as to keep the tangential error angle down to nearly zero. (The spec is 0.05 degree).

And with regard to "CD disease" linear tracking would not have prevented that, but DBX-encoded records might have slowed it down.

Tbg...Sometime (when no one can see you), get a hold of a Sony PS X800 turntable with servo controlled linear tracking arm. The "main problems" with linear tracking arms that you cite are very accurate. The Sony arm approach is completely different, and in my experience, flawless. But you won't believe it until you try one.

Tbg...I got mine about 1980. Not all Sony linear tracking tables had the "Biotracer" servo controlled arm, and not all "Biotracer" arms were linear tracking. Being an Engineer, I naturally had to get the service manual and see how this thing worked. Holy smokes! Working with balistic missile guidance systems I have seen a lot of schematics and block diagrams, but this Sony design is about as complex as anything I have seen. In fact, that is my only criticism.

As a have mentioned before, I became a convert to linear tracking after attending a High End seminar about the design and setup of pivoting arms. I concluded that there was no practical way to get all those forces and angles right across the recorded area. True, as you say, linear tracking arms have their own set of problems, but I think that I found one that did not have them.