Record Damage and Conical and Shibata Styluses

Here is a summary of the abstract to the patent for the Shibata..the idea seems actually brilliantly simple.The Shibata stylus-"a contact surface contour of a shape which is short in the longitudinal direction of the groove and long in the depth direction"...."A portion of a conical stylus body is partitioned from the remainder of the structure by one or two planes inclined at a specific angle relative to a centerline axis passing through the vertex point of the conical stylus body"...".One or two cut faces made on the body"..."Suitable points on the two lateral sides at the lower part of the edge line part and parts in the vicinity thereof contact"-the opposed wall of a groove."These have a large radius of curvature."

Stefanl, that's very interesting (patented Nov. 1973) In an interview, A.J. van den Hul says that he began manufacturing the line contact styli in 1976, so it was only an interval of two or three years.

Yes,I have the Van Den Hul patent somewhere and I will find out.I think it was finally approved around 1978.What I found striking was the claim in the patent that the Shibata profile does not wear out a record after a few plays as a "coventional elliptical" stylus does.The resonance point of the Shibata also that fluctuates with temperature,is outside of the frequency band used.Signal to noise ratio is higher due the type of cut,the resonant point has shifted also causing the disc itself to be more stable in relation to the stylus and thus less resonance is actually generated.The high frequency band performance is also improved in the 40-50Khz area.

The Shibata was developed for RCA's quadrophonic program ("CD 4") in the early 70's, as they needed a sharp stylus that could track the then-very high frequency 30 kHz. carrier signal that held the musical information for the back two channels.

The Shibata is not dead. The Grado Reference (the $1,200 model) and new Shibui (a highly modded Denon DL 103R) both use a Shibata, I believe, as do many other cartridges.

I have a van den Hul Frog, and am not certain that the care required to set azimuth and VTA with a Shibata / line-contact stylus is worth it. I'm all for vinyl, and don't mind cleaning records or getting off my ass to pick up the arm at the end of a record, but what a pain it is to dial these things in.

Hi, Tom. Hope you're well.

Was RCA connected to the Victor Co. of Japan Ltd. because the U.S patent states that they are the assignee and Norio Shibata the inventor?From what I have researched,it is worth spending the time to align a Shibata type stylus correctly as it will be rewarding.