VPI 2nd Pivot for 3D

Dear Raul,
Perhaps the moderator should step in at this point...  ;)

Yes, I've only heard the SAT tone arm via 320kbps needle drops versus CDs etc but it presents a persuasive argument even if unattainable for the many. If there are hidden distortions in there I like them! ;) :)

BTW before I took early retirement, our thermal engineers constantly used thermal imaging cameras to analyse circuit boards and develop thermal maps. It's probably what VDH used to get an approximation of the stylus interface? They could be quite handy for troubleshooting too.

I recall an EMI chemist commenting on one forum that the melting point of some vinyl formulations was as low as 112C (I know, a bit nerve wracking for the steam cleaning brigade;)
Best regards,
Bill

Dear @dodgealum : This video is from the Levinson tonearm and I hope that what we see between the the second 10 and the 16 second is not what happens with that fixed bearing tonearm manufactured by VPI:

https://www.youtube.com/watch?v=iTTLM9gPU9o

Anyway, the video is a very good fact that confirm what that those huge forces makes with the cartridge/tonearm and why unipivots are out of question.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

Dear @moonglum :  Handbook for enginners: "  "It has been experimentally shown that with such high pressures and forces of friction between stylus and the vinyl, that the outer skin layer of the record material melts as the tip slides over the plastic and then refreezes almost as fast as it melted. It has been suggested that since the melting temperature of vinyl is about 480 °F (248 °C) that the same temperature exists in the contact area.”

You can confirm here the fact you was thinking about and at the same time other additional fact that confirms about those very huge forces generated down there. 

Btw, I can tell you that my very high ignorance levels brought me to a extreme high frustration levels.  Never mind, such is life.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

@moonglum : "  Van Den Hul states :

"But the most important thing is record wear. I measured temperatures using a thermistor with a thin wire around the tip. A conical tip went up to about 140 deg C, but my one was 60 deg. I would like to come down further, but this was the lowest possible value."

R.

Hi Raul,
I agree it is confusing. I recall looking up the data at the time and the "248C" figure was known to me. I was somewhat surprised back then but given how easily vinyl warps next to central heating radiators I dismissed 248C as one possible value depending on composition and state i.e temperature at which it becomes fully liquid as opposed to becoming "soft"?

Clearly it does need to be a lower figure than 248C in order for the melting/reforming thesis to work?
Now you've got me wondering again. :)
I'll try to find the reference for you ;)

Best regards,
Bill