LP eccentricity, spindle hole center,The fix??????


Hi all,

I'm one of those audiophiles, 67 years of age, that wonders about the effect of the accuracy of the center hole. Some of the LPs I put on the TT have play due to a center hole that's punched out of round, too large or what ever.

I'm playing a record on a Denon 308 direct drive table using a system devised by a LJT Mfg in Canada to reduce eccentricity and help flatten warped records using a peripheral ring clamp in conjunction with a 1420 gram spindle clamp. The trio comes along with a cnc machined polycarbonate centering disc that straddles the record after the clamp ring is set registering on the outside diameter of the record. I can feel play regarding the center hole as I implement the OD centering device. I'll measure it tomorrow, just a few thousandths. The music sounds fine to my ears but I wonder what the relationship is to the record grooves, the outside diameter, and the center hole.

A while back a TT was made that had an extra arm that MEASURED THE ECCENTRICITY of the record and re centered the disc for play, it sells for big bucks if you can find one.

FINALLY, Your thoughts on the question?

regards, Ken Fritz
kftool
One thing to note is that there is nothing to prevent the eccentricity to be different on the two sides of the record. For example, the record may be perfectly centered on one side but off on the other, or it may be off on both sides but in different directions. Just a little extra thing to think of. :-)
Dear Ken: The fix????

IMHO, like in the human been healthy, the name of the game is to prevent not to fix.

We have to form an audio-association ( audiophiles/music lovers ) and ask to the RIAA ( or to the correspondent oficial institution ) to make a RIAA standard for a " perfect center hole " to all the LP manufacturers, this is what in my opinion we have to do not trying to fix things that are errors on the audio item maker.

We have to be serious on this subject and many others and give it a serious treatment looking for a final solution. IMHO I think we need to help us in a more definitive way.

Do you want to start? any one? who say, I.

Regards and enjoy the music.
Raul.
Hi Raul,

It's been a while since we crossed threads. I have a feeling that by now you have a few more tone arms and cartridges; Ain't it great! I'll send 50 bucks to kick it off if I can get a Happy meal coupon with my tax free donation.

regards, and" Enjoy the music." A friend once said that to me.

ken
Dear all, that standard for the center hole was made in late 1940ies when the technical/mechanical standards for the microgroove longplaying record were set.
Those standards were precise numbers.
The problem is poor quality control, the ever increasing need for cutting production costs and too little care in the manufacturing process.
Companies like King Records / JVC Japan and several of the smaller dedicated record companies did always present LPs with very precise center holes. Today the LP-manufacturing is such a small segment of the audio/video market, that this (we...) and its (our..) needs are of no interest at all for the industry.
Dear Jlin, you are right - very often the two sides do differ in their eccentricity. In that case the "alignment" has to be done for each side individual.