Not always true, I grant; but if there are standard dimensions (etc.) for an item, it's good to adhere to them unless there's a reason to deviate.
So, are there standard turntable dimensions? I have searched, both in the forum and on Google, for things like "turntable standards" and "RIAA turntable", etc., and got a lot of irrelevant things back. Surely someone, at some time, said that TTs should have a certain diameter, that spindles should be of a certain size +/- x, etc. - or at least said this of LPs, which would come to the same thing in the end.
My Linn has a platter diameter of 11 3/4" (298.5mm); and a spindle diameter of ~9/32" (7.26mm). Should I take these as normal dimensions? Is there some other critical measurement that should be standard as well?
Any help welcomed, including search phrases I didn't think of, and pointers to threads that I was too thick to find
Regards.
Aengus
So, are there standard turntable dimensions? I have searched, both in the forum and on Google, for things like "turntable standards" and "RIAA turntable", etc., and got a lot of irrelevant things back. Surely someone, at some time, said that TTs should have a certain diameter, that spindles should be of a certain size +/- x, etc. - or at least said this of LPs, which would come to the same thing in the end.
My Linn has a platter diameter of 11 3/4" (298.5mm); and a spindle diameter of ~9/32" (7.26mm). Should I take these as normal dimensions? Is there some other critical measurement that should be standard as well?
Any help welcomed, including search phrases I didn't think of, and pointers to threads that I was too thick to find
Regards.
Aengus
Most record platters are in or around 12 inches or 30cm in dia. Spindles tend to be about 7mm. in Dia. After that all other standards are set for each arm, or the ratio of gearing for motor pully to platter drive (sub- platter drive ) on belt drives etc. TT's usually have the most eccentric outer dimensions, set usually around designer's specs or ideas but if you want to have a table resemble close to the size of other gear 17inches wide by about 12 or 13 inches deep for a plinth is a good starting point.
vinylkid said:
No, in fact I can't think of any others that would even be candidates; but - as I have had demonstrated all too often - me not being able to think of something doesn't mean it wasn't important
Phileas's note about the possible desirability of conforming to norm for plinths is a case in point - fitting on a standard shelf is probably a good thing, all else being equal (though it never is, of course).
I've occasionally had LPs that were a very tight fit on the Linn spindle, though most fit just fine, and I suppose that the occasional tight fit is better than a frequent sloppy fit. Just wondered what (if any) the standards are for this.
Regards.
Aengus
No, in fact I can't think of any others that would even be candidates; but - as I have had demonstrated all too often - me not being able to think of something doesn't mean it wasn't important
Phileas's note about the possible desirability of conforming to norm for plinths is a case in point - fitting on a standard shelf is probably a good thing, all else being equal (though it never is, of course).
I've occasionally had LPs that were a very tight fit on the Linn spindle, though most fit just fine, and I suppose that the occasional tight fit is better than a frequent sloppy fit. Just wondered what (if any) the standards are for this.
Regards.
Aengus
Hi guys, there are RIAA standards for all the record dimensions like diameter and where the audio should start and end.
Because they are pretty old and American, the standards are in inches.
An LP works out at 302mm but there's no standard for platter diameter, so would an edge to the flat part of the platter at maybe 295mm give a little overhang to lift the disc off with?
The record hole is specced at 0.285 inches for a spindle of 9/32 (0.2812) and this goes way back to the dawn of the 78.
With a tolerance of +-001 for both, there should never have been a case where the record would actually not go on!
Dunno about your metric conversion - my Mitutyo Mic converts that to 7.144mm (?)
regards, Jeff
Because they are pretty old and American, the standards are in inches.
An LP works out at 302mm but there's no standard for platter diameter, so would an edge to the flat part of the platter at maybe 295mm give a little overhang to lift the disc off with?
The record hole is specced at 0.285 inches for a spindle of 9/32 (0.2812) and this goes way back to the dawn of the 78.
With a tolerance of +-001 for both, there should never have been a case where the record would actually not go on!
Dunno about your metric conversion - my Mitutyo Mic converts that to 7.144mm (?)
regards, Jeff
Good stuff.
Jeff, thanks for the measurement on the Rega. And jeff, probably good advice about the 9/32 diameter. I'll be having it machined, since I have neither the tools nor the skills for this task. The final form is still to be determined, subject to ongoing thinking about record clamps.
Casey, thanks for the thread pointer. I'd seen this thread but then forgotten it. I too will refer, at parties, to Sy as "fearful" - or wait, was it "fearsome" he was hoping for?
Did you end up making a reflex clamp? I've been following your TT thread with envy (not to say awe) and wondering how many (if any) of your ideas I can adapt to my plywood platter design. However, I don't recall seeing anything about record clamps there to date (sorry if I've just missed it).
Regards.
Aengus
Jeff, thanks for the measurement on the Rega. And jeff, probably good advice about the 9/32 diameter. I'll be having it machined, since I have neither the tools nor the skills for this task. The final form is still to be determined, subject to ongoing thinking about record clamps.
Casey, thanks for the thread pointer. I'd seen this thread but then forgotten it. I too will refer, at parties, to Sy as "fearful" - or wait, was it "fearsome" he was hoping for?
Did you end up making a reflex clamp? I've been following your TT thread with envy (not to say awe) and wondering how many (if any) of your ideas I can adapt to my plywood platter design. However, I don't recall seeing anything about record clamps there to date (sorry if I've just missed it).
Regards.
Aengus
To add in my 2 cents....
Standards were set for turntables, RIAA curves, cutting heads, start and finish diameters, lathes...ect...ect...
I have list of them in various books...
The key thing to keep in mind is very rarely were these standards followed or respected.... 99% of these turntables were sold to the commercial mass market and are total junk and in many cases WAY off any standard or no standard followed....
Records were stamped soo fast just to get them out the door..
The general public was not demanding better turntables and not demanding to adhere to any standards....they would just buy what was on the shelf and go with it....
There were no "turn-table police" out there that show up at a factory to enforce standards..... NOBODY CARES!!!!!!!!
Except us small group of audiofiles who are anal about the set-up...
The funny part is how anal some of us are in setting up our phono stages with such high precision to the RIAA curve....
Reality slapped me in the face when i actually worked on a number of cutting heads and cuting amps.... the inverse RIAA curves were not always correct and the parts used and the tolerances were not always good... In some cases the vertical and horizontal amps had different brand parts......
SOme of the German made stuff was actually impressive and well made...provided it was well maintained over the years....
But it seemed like VTA and RIAA acuracy was all "subjective" to who-ever set-up the cutting lathe....basically a big joke and the joke is on us...
To be fair there are a few companies that specialize in very carefull cutting of vinyl who do take the time to do things correctly but this is not the norm...
Chris
Standards were set for turntables, RIAA curves, cutting heads, start and finish diameters, lathes...ect...ect...
I have list of them in various books...
The key thing to keep in mind is very rarely were these standards followed or respected.... 99% of these turntables were sold to the commercial mass market and are total junk and in many cases WAY off any standard or no standard followed....
Records were stamped soo fast just to get them out the door..
The general public was not demanding better turntables and not demanding to adhere to any standards....they would just buy what was on the shelf and go with it....
There were no "turn-table police" out there that show up at a factory to enforce standards..... NOBODY CARES!!!!!!!!
Except us small group of audiofiles who are anal about the set-up...
The funny part is how anal some of us are in setting up our phono stages with such high precision to the RIAA curve....
Reality slapped me in the face when i actually worked on a number of cutting heads and cuting amps.... the inverse RIAA curves were not always correct and the parts used and the tolerances were not always good... In some cases the vertical and horizontal amps had different brand parts......
SOme of the German made stuff was actually impressive and well made...provided it was well maintained over the years....
But it seemed like VTA and RIAA acuracy was all "subjective" to who-ever set-up the cutting lathe....basically a big joke and the joke is on us...
To be fair there are a few companies that specialize in very carefull cutting of vinyl who do take the time to do things correctly but this is not the norm...
Chris
Hi,
Yes, you're absolutely right about record cutting standards. Just about none are really cut to the RIAA angle - even lathes that were supposed to be cutting at 25 degrees weren't in reality. Anyway, for the true nerd part of the fun is finding out just how an ancient, mass produced bit of plastic stands up to the "perfect" products of the computer age - not how bad an LP is but how good.
I think the ultimate example of "standards" is maybe the '78 record.
Guys who are serious about transcribing these say thet almost none are actually made at that speed and they can vary from maybe 60-something to nearly 90! I remember talking to someone who was transferring some important old recordings using really good gear and the expensive "cedar" software and he said that his problem with determining the actual speed of the cutting was to discover the pitch the orchestra (I think the Vienna Phil) had tuned to.
Against that the famous Atlanic Records lathe angles pale to insignificance.
As for turntable clamps, I've been using one for ages and I'm convinced that they do make a difference. I also think that it's important that it's either threaded or colleted onto the spindle, rather than just being a weight plonked on the record. This opens the way for endless nerd discussions (i'm guilty here) about grounding and paths and stuff.
I remember back at the dawn of the Teres project the rim clamp/weight was discussed a lot and it seems like a very good idea but, in practical terms, it's very hard to make compared to the regular clamp and probably a pain to use.
I'm in the process of re-working all the stuff on my old site onto the link below, so it's all a bit flakey at the moment, but I hope to be able to start to collect some useful opinions on this stuff there soon.
regards, Jeff
PS - Yeah, start and finish diameters. These are important for us when setting up any turntable, 'cos they effect the null points for the cartridge. So many engineers went outside the standards in order to squeeze that extra minute onto the side because I reckon they felt it was better than having to reduce the groove pitch and either reduce the dynamics or risk pre-echoes etc.
Yes, you're absolutely right about record cutting standards. Just about none are really cut to the RIAA angle - even lathes that were supposed to be cutting at 25 degrees weren't in reality. Anyway, for the true nerd part of the fun is finding out just how an ancient, mass produced bit of plastic stands up to the "perfect" products of the computer age - not how bad an LP is but how good.
I think the ultimate example of "standards" is maybe the '78 record.
Guys who are serious about transcribing these say thet almost none are actually made at that speed and they can vary from maybe 60-something to nearly 90! I remember talking to someone who was transferring some important old recordings using really good gear and the expensive "cedar" software and he said that his problem with determining the actual speed of the cutting was to discover the pitch the orchestra (I think the Vienna Phil) had tuned to.
Against that the famous Atlanic Records lathe angles pale to insignificance.
As for turntable clamps, I've been using one for ages and I'm convinced that they do make a difference. I also think that it's important that it's either threaded or colleted onto the spindle, rather than just being a weight plonked on the record. This opens the way for endless nerd discussions (i'm guilty here) about grounding and paths and stuff.
I remember back at the dawn of the Teres project the rim clamp/weight was discussed a lot and it seems like a very good idea but, in practical terms, it's very hard to make compared to the regular clamp and probably a pain to use.
I'm in the process of re-working all the stuff on my old site onto the link below, so it's all a bit flakey at the moment, but I hope to be able to start to collect some useful opinions on this stuff there soon.
regards, Jeff
PS - Yeah, start and finish diameters. These are important for us when setting up any turntable, 'cos they effect the null points for the cartridge. So many engineers went outside the standards in order to squeeze that extra minute onto the side because I reckon they felt it was better than having to reduce the groove pitch and either reduce the dynamics or risk pre-echoes etc.
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