Why Linear Tracking never took off?

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.

Eldartford . . Good point, linear tracking alone would not have made a mass market difference. Correction to yesterday's note: though not the Sony's equal, the Phase Linear spec is 0.2°

At one time used a parametric equalizer, SAE 5k impulse noise reduction (click and pop filter) and a dbx 3bx. The remote was nice, but later realized (TAS) how important speaker placement and the minimal approach can be. With two grand boxed up, the unveiled clarity outweighed other benefits (to my wooden ears). Placed using a spectrum analyzer, my pathetic mid-fi two ways placed a realistic upright bass in my room. Recently discovered they can surpass Infinity RS-IIb's on basic instrumental works.

A decent cartridge costs more than Joe Schmo's system, we're stuck with the source material.

Getting late and for now, off this tangent,

Steve

As I remember it, the first significant stab at a "linear tracking" tonearm was the one fitted to the 1973 Garrard Zero-100 turntable. This was basically a conventional pivoting tonearm, but with a cantilever meachanism which rotated the headshell as it tracked across the LP, theoretically correcting the tracking error in the process. The arm was made of plastic, and the 'table was idler driven. Needless to say, it sounded pretty awful. The B&O came out a couple of years later and was a commercial success, if not a compelling audiophile performer.

I believe that the biggest obstacle to a satisfactory affordable linear tracking design is the lack of a simple mechanism to drive the arm along its linear bearing. It seems to me that this is where the costs of producing the existing molto expensivo designs builds from.

FWIW, I would expect that above a certain performance level, a linear tracking arm would indeed offer the potential for further sonic improvements. I say this by employing an arm-waving argument that says the geometric magnitude of linear tracking errors is potentially larger than the geometric correction applied by VTA adjustments, etc.

The Garrard Zero 100 got undeserved bad press and was often unfairly maligned - it's a little hard to understand why because it was a leader in much more than just zero tracking error.

It had:

an all-metal sub chassis suspended on foam cushioned coils.

a 5lb, hand balanced, cast aluminum, belt driven (not rim driven) platter running on an inverted, hardened single ball main bearing with the bearing situated at the center of gravity of the platter.

a balanced, synchronous motor so quiet and vibration free that, although independantly suspended, could probably run hard mounted to the sub-chassis without intruding.

a machined aluminum (not plastic) double rectangular (larger on smaller) section low mass tone-arm, articulated to track at zero error across the full width of the record. The cantilever was a thin (2 mm) aluminum tube that added about 2 grams to the overall mass of the arm.

and magnetic anti-skate with graduated scales for both conical and eliptical stylii. The amount of antiskate force applied automatically reduced as the arm tracked across the record.

I bought a Zero 100SB new in 1973 and have been using it ever since. I also own a Rega Planar 3/RB300, a Thorens 125/Rabco SL8E and Linn LP12/SME 3012. I'm a bit of a collector of TT classics and have a few more non-working examples under the bench waiting to join the ranks. I love all these turntables and can say without fear or favour that the Garrard holds its own in performance with the others and is way out in front in terms of character. It certainly deserves its place in this little collection of classics.

The main problems with the Zero 100 were marketing ones rather than performance. It had a clunky, noisy auto return mechanism that looked and sounded cheap and nasty in operation and a plastic headshell that had a non-locking slide out cartridge carrier that looked like it should be a performance weak point, but, in practice, turns out not to be. The auto return mechanism has no connection to the arm when not in use so its operation in no way affects the quality of the arm's performance and it still works today in exactly the same cheap and nasty, clunky, noisy, efficient way that it did in 1973.

If Garrard had incorporated a classier auto return mechanism, a single piece headshell and had charged significantly more for the turntable it would probably have had an easier ride into the high end where it belongs.

Tassiemike, Thanks for the perspective on the Zero 100. I remember looking at one back in the 70s, before I knew anything about hifi. I was intrigued by the nifty solution that the articulating cantilever design provided for linear tracking. I recall the salesman badmouthed it, disparaging the design by claiming the cantilever assembly added too much mass and the extra pivots added too much friction and had too much play to provide satisfactory stability. The clincher was the unrefined auto return mechanism you mentioned, which turned me off as soon as he operated it. I got a Benjamin Miracord Elac 50H instead (still have it!). I'm glad to learn the real story on the Zero 100 from you, after all these years.