Record Damage and Conical and Shibata Styluses

Hi Tom, yes I have the same memory about Shibata as you do. That they never really took off, although I don't know why and never owned one. But I wondered if it might be that they were simply succeeded by the line contact type. I just can't remember the exact timeline anymore.

The patent was originally submitted on March 8 1972 and patented in November 27 1973.Now in talking to a Linn dealer from whom I purchased a Linn K18 Mark 2 cartridge second-hand,he stated quite unequivocally that this cartridge's profile was a Shibata and said he thought it's high-end was especially good.A lot of people also fondly remember this cartridge,one poster on Vinyl Asylum I think even stating that it was the best moving-magnet cartridge ever made.I have it on a second table and it outdoes a Denon 103,but that's not really broken-in.

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.