About 9 months ago there was some discussion about the eccentricity of vinyl records. At the moment, the issue receives a lot of attention because of the test record and app of “Dr. Feickert”. The app shows the stability of the rotational speed of the turntable platter by the instability of a 3150 Hz test frequency. So it shows the eccentricity of the record too...
There is an easy way to correct the eccentricity of every vinyl record to about 0,1 mm if it is possible to “drill” a new large hole in every record (40 mm diameter). The principle is easy and you find the explanation here.
Nevertheless, there is a practical question: how can we drill a 40 mm hole into an LP without increasing the eccentricity of the record? It must be a "drill" like the one above.
So my question is: who has ever seen a “drill” like this? Or... who has a better idea to drill these new record holes in a perfect way? Because nobody wants to ruin his beautiful record collection...
There is an easy way to correct the eccentricity of every vinyl record to about 0,1 mm if it is possible to “drill” a new large hole in every record (40 mm diameter). The principle is easy and you find the explanation here.
Nevertheless, there is a practical question: how can we drill a 40 mm hole into an LP without increasing the eccentricity of the record? It must be a "drill" like the one above.
So my question is: who has ever seen a “drill” like this? Or... who has a better idea to drill these new record holes in a perfect way? Because nobody wants to ruin his beautiful record collection...
@billshurv,
I don't know what is a "rokan". So I googled....
Oilcompanies, drugs, part of Indonesia, etc., etc.
But no mechanical tool...
Can you give some more details?
I don't know what is a "rokan". So I googled....
Oilcompanies, drugs, part of Indonesia, etc., etc.
But no mechanical tool...
Can you give some more details?
@billshurv,
You are an employee of Roksan audio? Because only the Nakamichi auto centring turntable can centre eccentric records (but these turntables are not available anymore).
You are an employee of Roksan audio? Because only the Nakamichi auto centring turntable can centre eccentric records (but these turntables are not available anymore).
Wow a lot of work. You could probably get a 40mm hole saw and replace the pilot with a rod of exactly the right diameter. Why not just drill the hole to a standard 45RPM one, you could then bother with the alignment and when you don't feel like it just use an adapter.
Second idea take a solid metal 45 RPM adapter and have a friend make an insert with an eccentric plug with the normal 33.3 sized hole. You could then index the rotation and record the setting for each of your LP's. I'm surprised this does not exist already.
EDIT - Not surprised, it requires drilling out the center of your LP's
Second idea take a solid metal 45 RPM adapter and have a friend make an insert with an eccentric plug with the normal 33.3 sized hole. You could then index the rotation and record the setting for each of your LP's. I'm surprised this does not exist already.
EDIT - Not surprised, it requires drilling out the center of your LP's
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He was just saying that with no spindle you can just move the LP freely to its correct center.
Exactly. No affiliation, just owned a xerxes for last 24 years (makes me feel old). Have never had an issue with off centre records with this setup (but have very few records where this is a problem anyway).
Hello All
If someone was actually serious about experimenting with an LP centering device, I would suggest to design it such that the required center hole would be as small as possible, certainly not 40mm. Then, I would design a tool to PUNCH the hole. Trying to drill the hole would result in a mess!
There are commercially available punch and die sets commonly used to punch holes into the front panels of various electronic equipment. I haven't checked the internet on this but the name Greenlee comes to mind.
Sincerely,
Ralf
If someone was actually serious about experimenting with an LP centering device, I would suggest to design it such that the required center hole would be as small as possible, certainly not 40mm. Then, I would design a tool to PUNCH the hole. Trying to drill the hole would result in a mess!
There are commercially available punch and die sets commonly used to punch holes into the front panels of various electronic equipment. I haven't checked the internet on this but the name Greenlee comes to mind.
Sincerely,
Ralf
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Since center-hole to groove concentricity is determined by the mold machining (which is generally very high tolerance), is there actual data demonstrating that it's a common problem? And that the offset is constant through the record? I can see the possibility of some center-hole to edge variation because of variables in the molding process, but that's a visual thing, not really related to the grooves.
Hello SY,
I don't know of any actual data, but I have several Lp's where the tone arm visibly oscillates toward and away from the center spindle. One of the worst is a Merle Haggard album which I keep at the ready when I demonstrate my own tangentially tracking tone arm.
A true tangentially tracking tone arm is of course not affected by eccentric LP's.
Sincerely,
Ralf
I don't know of any actual data, but I have several Lp's where the tone arm visibly oscillates toward and away from the center spindle. One of the worst is a Merle Haggard album which I keep at the ready when I demonstrate my own tangentially tracking tone arm.
A true tangentially tracking tone arm is of course not affected by eccentric LP's.
Sincerely,
Ralf
Could you give me an example? If I can find one, I'll stick it on the stage of one of our micro-CMMs and see if that's actually the cause of what you're seeing.
Huh? The eccentricity causes the groove velocity to frequency modulate at .55Hz away from what the cutting lathe did. Simple geometry, the effective radius varies at .55Hz.
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@billshurv,
Sorry, excuses! I thought you meant an automatic spindle: “the spindle comes out”.
@scott wurcer,
I have nice hole saws, but these are not useful (too much tolerance).
@Straight Tracker,
Thanks! The speedpunch of Greenlee looks impressive and it is possible to centre everything without much tolerance. I will study it the next days.
@SY,
Nearly all the new LP’s I bought are too much eccentric. It doesn’t matter they sell high quality 180 gram LP’s when the centre hole is not nearly centric (for both spiral grooves). Records with an eccentricity above 0,1 mm are simply no high fidelity in relation to the specifications of a good CD-player. Unfortunately, nearly all the records you can buy have an eccentricity that’s above 0,1 mm. Solving this problem in an easy - not expensive - way is very important for everyone who listen to vinyl.
Sorry, excuses! I thought you meant an automatic spindle: “the spindle comes out”.
@scott wurcer,
I have nice hole saws, but these are not useful (too much tolerance).
@Straight Tracker,
Thanks! The speedpunch of Greenlee looks impressive and it is possible to centre everything without much tolerance. I will study it the next days.
@SY,
Nearly all the new LP’s I bought are too much eccentric. It doesn’t matter they sell high quality 180 gram LP’s when the centre hole is not nearly centric (for both spiral grooves). Records with an eccentricity above 0,1 mm are simply no high fidelity in relation to the specifications of a good CD-player. Unfortunately, nearly all the records you can buy have an eccentricity that’s above 0,1 mm. Solving this problem in an easy - not expensive - way is very important for everyone who listen to vinyl.
Hi scott,
You are quite right of course. A given frequency would then vary up and down like a very slow vibrato and as such might be called WOW. I am quite sensitive to wow and flutter but when I listen to the excessively eccentric Merle Haggard LP, mentioned in my post # 12, I don't notice any WOW.
Sincerely,
Ralf
You are quite right of course. A given frequency would then vary up and down like a very slow vibrato and as such might be called WOW. I am quite sensitive to wow and flutter but when I listen to the excessively eccentric Merle Haggard LP, mentioned in my post # 12, I don't notice any WOW.
Sincerely,
Ralf
A stamper punch is the solution. You can centre and punch the disc with this device.
Record Products of America
http://www.sibert.co.uk/products/spslt-punching-machine
Record Products of America
http://www.sibert.co.uk/products/spslt-punching-machine
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