Vinyl Old timers: HK's and Rabco's

Ivanj is correct. The original Rabco SL 8 was constructed with a wide and flat head shell that formed the entire tonearm except for the block and bearing mechanism that it plugged into.

I owned and modified at least three of these, getting excellent performance for the early 1970's. I mounted the early model we are discussing on several turntables including Thorens, Luxman and Linn while I worked in retail audio.

If you buy one and need information, I remember quite a few tricks, including several ways to improve tracking, and a way to speed up the cue and lift.

Sean, One of the mods I did on the early flat tone arm Rabco's was to reduce flex in the giant head shell (arm).

Originally this design was way too flexible, having been formed from wafer thin aluminum sheet with the edges bent over to increase strength. Certainly it was lightweight, but provided less than a perfect platform to secure the cartridge.

Add to this, the counterbalance was large and heavy in order to accommodate (heavy) cartridges of that era. I had a machine shop mill the counterbalance where it's weight balanced against my reference cartridge when fitted very close to the bearing point. (Reducing the moment of inertia).

I substituted other materials for the flat aluminum sheet design with balsa wood, Oak, steel and Plexiglas. Each offering trade off performance over the stock material.

Today I would consider Carbon fiber or other modern lightweight, but stiff materials to substitute for the aluminum.

I never heard the tubular version of the Rabco, but would assume it would be superior in rigidity to the flat design.

Jeez Crump your as bad as me with the mod thing! Why don't you build a preamp and name it BlowTorch or something?