Re: [Phono-L] shrinking cylinder speed?
I've never heard of this. Must be a fascinating read. Where did you hear about cylinders being recorded at a different speed than the intended playback? Where can I find this information and dig a little deeper? Because regardless of any allowances Edison may or may not have made for inherent manufacturing shrinkage, the unchangeable laws I've outlined below applied then as they do now. It's hard to imagine the Old Man being so completely wrong about something like that. As such, I ain't buyin' it (nothing personal)! Best,Robert Date: Mon, 11 Jul 2011 22:05:02 -0500 From: rich-m...@octoxol.com To: phono-l@oldcrank.org Subject: Re: [Phono-L] shrinking cylinder speed? The physical surface shrinks. This is why they were recorded at a speed different than the 160 desired final result. The actual question was how was the 160 RPM speed checked? And with an accuracy of? Or the actual mastering speed. On 07/11/2011 09:13 PM, Robert Wright wrote: Not sure, I know that 33.3rpm was determined (at random) by some readily available reduction gears that were applied to the electric 78rpm motors of the day, or so I have heard/read regarding Pict-ur-music discs -- if memory serves. I wonder how Thom came up with 160. There were other speeds as well, weren't there? I'm sure Pathe players ran at weird speeds, just because Pathe did everything kinda non-'standard', but were earlier Edisons anything other than 160? Radial and axial shrinkage would have no effect on musical pitch of a given cylinder, as the groove speed (relative to stationary stylus) would decrease proportionately with the cylinder's size; i.e., if the cylinder shrunk 3%, so would the relative groove speed, so the pitch would remain constant. As an illustration: 160rpm comes to 2.6 revs per second. If we scratched 100 perfectly spaced lines 1/8 deep along the length of a blank cylinder and played it at 160rpm, we'd hear a pitch of 266. Hz (a little bit sharp of C below middle C). If we shaved 1/16 off of its surface (or any amount shy of 1/8, actually), we'd still hear the exact same frequency by playing it back at 160rpm (albeit with less volume). In order for the pitch of a shrunken cylinder to change, the relative groove speed would have to change, and that would require the grooves to contract like a boa constrictor on its prey, and as the grooves are a part of the physical surface, that ain't go nn a happen. Best, Robert Date: Mon, 11 Jul 2011 19:09:08 -0500 From: rich-m...@octoxol.com To: phono-l@oldcrank.org Subject: Re: [Phono-L] shrinking cylinder speed? There is both radial and axial shrinkage. Beyond that, how did Edison Co. determine 160 RPM? On 07/11/2011 05:20 PM, Robert Wright wrote: Hi all, quick question after a long absence: if a given point along the circumference of a cylinder passes a fixed position exactly 160 times per minute, why would the pitch change? Even if it shrunk to half its size, but was still played at 160 rpm, the wavelengths of the recorded frequencies in the groove wouldn't change in relation to playback time. They'd be quieter, for sure, but that's about it. It's a linear velocity system -- it's not the same as a disc record, where shrinkage towards the spindle WOULD make a difference, since the groove-to-stylus speed changes relative to diameter of stylus path. (Of course, testing that would require a shifting disc groove that would coil like a spring as the diameter decreased, an example of how theoretical physics don't always translate to a physical world.) If the cylinder's rotation was powered by a motor capstan with a rubber wheel attached to it that was in direct contact with the cylinder surface, there might be the tiniest amount of change in the speed, but at 160rpm (speaking in real-world terms here), the maximum shrinkage that would still allow a decent mandrel fit would be negligible. If we're talking about a difference in musical pitch that might render playback audibly inaccurate, I think even this example would be undetectable by even the most musical ears. I'm a career musician who has had (documented) perfect pitch for nearly 40 years, and I can only distinguish the difference between 78rpm and 80rpm (a difference of 2.5%, surely more than the average cylinder shrinkage, right?) in a direct A/B comparison, and even then with some difficulty. As a cylinder phonograph transfers its motor power to a non-shrinking mandrel and not the cylinder directly, I'm calling this a wives' tale. Best,Robert PS - 1/16 of shrinkage of a 2-5/32 cylinder comes out to a difference of 2.898%. What percent of 160rpm that would translate to in a capstan/rubber wheel-driven system is something I have no idea how to compute! Date: Thu, 7 Jul 2011 14:54:51 -0500 From
Re: [Phono-L] shrinking cylinder speed?
In a message dated 7/12/2011 3:56:12 P.M. Eastern Daylight Time, esrobe...@hotmail.com writes: I've never heard of this. Must be a fascinating read. Where did you hear about cylinders being recorded at a different speed than the intended playback? that has to be the case because the physical (molded) cylinders sold to the public are not the identical cylinders that were mastered. There are usual a couple of steps, generating sub-masters, and each step causes shrinkage of the resulting cylinder as it comes out of the mold. A 2-minute style Edison wax cylinder would probably be recorded around 97+ tpi when it was in the studio, and in two interim steps, result in a 100 tpi final gold-molded version sold to his customers. It is an interesting question as to the parallel impact on the subsequent rpm's. Allen _www.phonobooks.com_ (http://www.phonobooks.com) ___ Phono-L mailing list http://phono-l.oldcrank.org
Re: [Phono-L] shrinking cylinder speed?
The pitch of the lead screw was adjusted for shrink for linear shrink. On 07/12/2011 02:31 PM, Robert Wright wrote: I've never heard of this. Must be a fascinating read. Where did you hear about cylinders being recorded at a different speed than the intended playback? Where can I find this information and dig a little deeper? Because regardless of any allowances Edison may or may not have made for inherent manufacturing shrinkage, the unchangeable laws I've outlined below applied then as they do now. It's hard to imagine the Old Man being so completely wrong about something like that. As such, I ain't buyin' it (nothing personal)! Best,Robert Date: Mon, 11 Jul 2011 22:05:02 -0500 From: rich-m...@octoxol.com To: phono-l@oldcrank.org Subject: Re: [Phono-L] shrinking cylinder speed? The physical surface shrinks. This is why they were recorded at a speed different than the 160 desired final result. The actual question was how was the 160 RPM speed checked? And with an accuracy of? Or the actual mastering speed. On 07/11/2011 09:13 PM, Robert Wright wrote: Not sure, I know that 33.3rpm was determined (at random) by some readily available reduction gears that were applied to the electric 78rpm motors of the day, or so I have heard/read regarding Pict-ur-music discs -- if memory serves. I wonder how Thom came up with 160. There were other speeds as well, weren't there? I'm sure Pathe players ran at weird speeds, just because Pathe did everything kinda non-'standard', but were earlier Edisons anything other than 160? Radial and axial shrinkage would have no effect on musical pitch of a given cylinder, as the groove speed (relative to stationary stylus) would decrease proportionately with the cylinder's size; i.e., if the cylinder shrunk 3%, so would the relative groove speed, so the pitch would remain constant. As an illustration: 160rpm comes to 2.6 revs per second. If we scratched 100 perfectly spaced lines 1/8 deep along the length of a blank cylinder and played it at 160rpm, we'd hear a pitch of 266. Hz (a little bit sharp of C below middle C). If we shaved 1/16 off of its surface (or any amount shy of 1/8, actually), we'd still hear the exact same frequency by playing it back at 160rpm (albeit with less volume). In order for the pitch of a shrunken cylinder to change, the relative groove speed would have to change, and that would require the grooves to contract like a boa constrictor on its prey, and as the grooves are a part of the physical surface, that ain't go nn a happen. Best, Robert Date: Mon, 11 Jul 2011 19:09:08 -0500 From: rich-m...@octoxol.com To: phono-l@oldcrank.org Subject: Re: [Phono-L] shrinking cylinder speed? There is both radial and axial shrinkage. Beyond that, how did Edison Co. determine 160 RPM? On 07/11/2011 05:20 PM, Robert Wright wrote: Hi all, quick question after a long absence: if a given point along the circumference of a cylinder passes a fixed position exactly 160 times per minute, why would the pitch change? Even if it shrunk to half its size, but was still played at 160 rpm, the wavelengths of the recorded frequencies in the groove wouldn't change in relation to playback time. They'd be quieter, for sure, but that's about it. It's a linear velocity system -- it's not the same as a disc record, where shrinkage towards the spindle WOULD make a difference, since the groove-to-stylus speed changes relative to diameter of stylus path. (Of course, testing that would require a shifting disc groove that would coil like a spring as the diameter decreased, an example of how theoretical physics don't always translate to a physical world.) If the cylinder's rotation was powered by a motor capstan with a rubber wheel attached to it that was in direct contact with the cylinder surface, there might be the tiniest amount of change in the speed, but at 160rpm (speaking in real-world terms here), the maximum shrinkage that would still allow a decent mandrel fit would be negligible. If we're talking about a difference in musical pitch that might render playback audibly inaccurate, I think even this example would be undetectable by even the most musical ears. I'm a career musician who has had (documented) perfect pitch for nearly 40 years, and I can only distinguish the difference between 78rpm and 80rpm (a difference of 2.5%, surely more than the average cylinder shrinkage, right?) in a direct A/B comparison, and even then with some difficulty. As a cylinder phonograph transfers its motor power to a non-shrinking mandrel and not the cylinder directly, I'm calling this a wives' tale. Best,Robert PS - 1/16 of shrinkage of a 2-5/32 cylinder comes out to a difference of 2.898%. What percent of 160rpm that would translate to in a capstan/rubber wheel-driven system is something I have no idea how to compute! Date: Thu, 7 Jul 2011 14:54:51 -0500 From: rich-m...@octoxol.com Some
Re: [Phono-L] shrinking cylinder speed?
Very interesting! I've wondered how many steps in Edison's gold-moulded and/or Blue Amberol manufacturing process(es) are still reflected in today's disc manufacturing. I tend to think electroplating would only effect a negligible difference in the finished cylinder's diameter -- if for no other reason, simply to conserve gold and thereby, cost. One question though, what is TPI (?? per inch) and how is it related to what speed the masters were recorded at? Again, changes in diameter would not affect concert pitch -- if it was recorded at 160, the finished product would play accurately at 160. Are there any definitive books and/or articles about Edison's entire recording and manufacturing processes top to bottom? What are the best ones to start with? Thanks,Robert From: allena...@aol.com Date: Tue, 12 Jul 2011 16:34:21 -0400 To: phono-l@oldcrank.org Subject: Re: [Phono-L] shrinking cylinder speed? In a message dated 7/12/2011 3:56:12 P.M. Eastern Daylight Time, esrobe...@hotmail.com writes: I've never heard of this. Must be a fascinating read. Where did you hear about cylinders being recorded at a different speed than the intended playback? that has to be the case because the physical (molded) cylinders sold to the public are not the identical cylinders that were mastered. There are usual a couple of steps, generating sub-masters, and each step causes shrinkage of the resulting cylinder as it comes out of the mold. A 2-minute style Edison wax cylinder would probably be recorded around 97+ tpi when it was in the studio, and in two interim steps, result in a 100 tpi final gold-molded version sold to his customers. It is an interesting question as to the parallel impact on the subsequent rpm's. Allen _www.phonobooks.com_ (http://www.phonobooks.com) ___ Phono-L mailing list http://phono-l.oldcrank.org ___ Phono-L mailing list http://phono-l.oldcrank.org
Re: [Phono-L] shrinking cylinder speed?
This follows Robert's thoughts as well (I think). This is all about in-plane shrinkage. So the original cylinder is longer to accommodate this shrinkage and the speed at which the cutter would move laterally across the cylinder would have to be slightly faster. However, wouldn't the recording speed still be 160rpm? Glenn From: allena...@aol.com allena...@aol.com To: phono-l@oldcrank.org Sent: Tue, July 12, 2011 4:34:21 PM Subject: Re: [Phono-L] shrinking cylinder speed? In a message dated 7/12/2011 3:56:12 P.M. Eastern Daylight Time, esrobe...@hotmail.com writes: I've never heard of this. Must be a fascinating read. Where did you hear about cylinders being recorded at a different speed than the intended playback? that has to be the case because the physical (molded) cylinders sold to the public are not the identical cylinders that were mastered. There are usual a couple of steps, generating sub-masters, and each step causes shrinkage of the resulting cylinder as it comes out of the mold. A 2-minute style Edison wax cylinder would probably be recorded around 97+ tpi when it was in the studio, and in two interim steps, result in a 100 tpi final gold-molded version sold to his customers. It is an interesting question as to the parallel impact on the subsequent rpm's. Allen _www.phonobooks.com_ (http://www.phonobooks.com) ___ Phono-L mailing list http://phono-l.oldcrank.org ___ Phono-L mailing list http://phono-l.oldcrank.org
Re: [Phono-L] shrinking cylinder speed?
It would indeed, Glenn! Rich's last comment helped me understand this -- one of the original questions was regarding playback rpm, so I've been thinking in terms of concert pitch, which wouldn't be affected by shrinkage, instead of lateral pitch, i.e., the lines per inch, which certainly would. Since Edison's team used to refer to lines per inch as 'pitch', i.e. 2 minute pitch or a pitch of 100 lines per inch, etc., it's easy to get confused. It totally makes sense now. Musical pitch would indeed remain constant. Thanks to you both for the clarification! I guess we should be thankful that the amount of lateral shrinkage could never exceed the amount of play in most reproducers -- more foresight from our benevolent meisterinventor, or happy accident, who knows? :-) (Is it ironic that they cut at 97tpi for manufactured playback at 100tpi, and 100 yrs later it's probably closer to 97tpi?) Best, Robert Date: Tue, 12 Jul 2011 14:30:21 -0700 From: majesticrec...@snet.net To: phono-l@oldcrank.org Subject: Re: [Phono-L] shrinking cylinder speed? This follows Robert's thoughts as well (I think). This is all about in-plane shrinkage. So the original cylinder is longer to accommodate this shrinkage and the speed at which the cutter would move laterally across the cylinder would have to be slightly faster. However, wouldn't the recording speed still be 160rpm? Glenn From: rich-m...@octoxol.com To: phono-l@oldcrank.org Subject: Re: [Phono-L] shrinking cylinder speed? The pitch of the lead screw was adjusted for shrink for linear shrink. ___ Phono-L mailing list http://phono-l.oldcrank.org
Re: [Phono-L] shrinking cylinder speed?
Info is hard to come by as Edison gave up on patents and went with corporate secrets and compartmentalization. The pitch issue is that the 160 RPM was determined by timing carriage travel on a spring drive machine. This is not incredibly accurate. Shawn Bori is the person who has spent the most time digging out the entire process. On 07/12/2011 04:14 PM, Robert Wright wrote: Very interesting! I've wondered how many steps in Edison's gold-moulded and/or Blue Amberol manufacturing process(es) are still reflected in today's disc manufacturing. I tend to think electroplating would only effect a negligible difference in the finished cylinder's diameter -- if for no other reason, simply to conserve gold and thereby, cost. One question though, what is TPI (?? per inch) and how is it related to what speed the masters were recorded at? Again, changes in diameter would not affect concert pitch -- if it was recorded at 160, the finished product would play accurately at 160. Are there any definitive books and/or articles about Edison's entire recording and manufacturing processes top to bottom? What are the best ones to start with? Thanks,Robert From: allena...@aol.com Date: Tue, 12 Jul 2011 16:34:21 -0400 To: phono-l@oldcrank.org Subject: Re: [Phono-L] shrinking cylinder speed? In a message dated 7/12/2011 3:56:12 P.M. Eastern Daylight Time, esrobe...@hotmail.com writes: I've never heard of this. Must be a fascinating read. Where did you hear about cylinders being recorded at a different speed than the intended playback? that has to be the case because the physical (molded) cylinders sold to the public are not the identical cylinders that were mastered. There are usual a couple of steps, generating sub-masters, and each step causes shrinkage of the resulting cylinder as it comes out of the mold. A 2-minute style Edison wax cylinder would probably be recorded around 97+ tpi when it was in the studio, and in two interim steps, result in a 100 tpi final gold-molded version sold to his customers. It is an interesting question as to the parallel impact on the subsequent rpm's. Allen _www.phonobooks.com_ (http://www.phonobooks.com) ___ Phono-L mailing list http://phono-l.oldcrank.org ___ Phono-L mailing list http://phono-l.oldcrank.org ___ Phono-L mailing list http://phono-l.oldcrank.org
Re: [Phono-L] shrinking cylinder speed?
Yes, except the 160 was not very accurately determined. Radial shrinkage after molding is not uniform either. On 07/12/2011 04:30 PM, Glenn Longwell wrote: This follows Robert's thoughts as well (I think). This is all about in-plane shrinkage. So the original cylinder is longer to accommodate this shrinkage and the speed at which the cutter would move laterally across the cylinder would have to be slightly faster. However, wouldn't the recording speed still be 160rpm? Glenn From: allena...@aol.comallena...@aol.com To: phono-l@oldcrank.org Sent: Tue, July 12, 2011 4:34:21 PM Subject: Re: [Phono-L] shrinking cylinder speed? In a message dated 7/12/2011 3:56:12 P.M. Eastern Daylight Time, esrobe...@hotmail.com writes: I've never heard of this. Must be a fascinating read. Where did you hear about cylinders being recorded at a different speed than the intended playback? that has to be the case because the physical (molded) cylinders sold to the public are not the identical cylinders that were mastered. There are usual a couple of steps, generating sub-masters, and each step causes shrinkage of the resulting cylinder as it comes out of the mold. A 2-minute style Edison wax cylinder would probably be recorded around 97+ tpi when it was in the studio, and in two interim steps, result in a 100 tpi final gold-molded version sold to his customers. It is an interesting question as to the parallel impact on the subsequent rpm's. Allen _www.phonobooks.com_ (http://www.phonobooks.com) ___ Phono-L mailing list http://phono-l.oldcrank.org ___ Phono-L mailing list http://phono-l.oldcrank.org ___ Phono-L mailing list http://phono-l.oldcrank.org
Re: [Phono-L] shrinking cylinder speed?
Could whomever is in charge of this Phono L thing, please take me off the email list? Thank you, Jay On Tue, Jul 12, 2011 at 3:22 PM, Robert Wright esrobe...@hotmail.comwrote: It would indeed, Glenn! Rich's last comment helped me understand this -- one of the original questions was regarding playback rpm, so I've been thinking in terms of concert pitch, which wouldn't be affected by shrinkage, instead of lateral pitch, i.e., the lines per inch, which certainly would. Since Edison's team used to refer to lines per inch as 'pitch', i.e. 2 minute pitch or a pitch of 100 lines per inch, etc., it's easy to get confused. It totally makes sense now. Musical pitch would indeed remain constant. Thanks to you both for the clarification! I guess we should be thankful that the amount of lateral shrinkage could never exceed the amount of play in most reproducers -- more foresight from our benevolent meisterinventor, or happy accident, who knows? :-) (Is it ironic that they cut at 97tpi for manufactured playback at 100tpi, and 100 yrs later it's probably closer to 97tpi?) Best, Robert Date: Tue, 12 Jul 2011 14:30:21 -0700 From: majesticrec...@snet.net To: phono-l@oldcrank.org Subject: Re: [Phono-L] shrinking cylinder speed? This follows Robert's thoughts as well (I think). This is all about in-plane shrinkage. So the original cylinder is longer to accommodate this shrinkage and the speed at which the cutter would move laterally across the cylinder would have to be slightly faster. However, wouldn't the recording speed still be 160rpm? Glenn From: rich-m...@octoxol.com To: phono-l@oldcrank.org Subject: Re: [Phono-L] shrinking cylinder speed? The pitch of the lead screw was adjusted for shrink for linear shrink. ___ Phono-L mailing list http://phono-l.oldcrank.org ___ Phono-L mailing list http://phono-l.oldcrank.org
Re: [Phono-L] shrinking cylinder speed?
All this talk of shrinkage makes me feel as if I'm in an episode of Seinfeld ;-) Spring motor, leather belt drive, and questionable tolerances do not meet the level of laser precision. Get it close, tune to ear, and enjoy. Loran On Tue, Jul 12, 2011 at 3:36 PM, Rich rich-m...@octoxol.com wrote: Yes, except the 160 was not very accurately determined. Radial shrinkage after molding is not uniform either. ___ Phono-L mailing list http://phono-l.oldcrank.org
Re: [Phono-L] shrinking cylinder speed?
This is Like Hotel California, you can never leave On 07/12/2011 05:58 PM, Jay Horenstein wrote: Could whomever is in charge of this Phono L thing, please take me off the email list? Thank you, Jay On Tue, Jul 12, 2011 at 3:22 PM, Robert Wrightesrobe...@hotmail.comwrote: It would indeed, Glenn! Rich's last comment helped me understand this -- one of the original questions was regarding playback rpm, so I've been thinking in terms of concert pitch, which wouldn't be affected by shrinkage, instead of lateral pitch, i.e., the lines per inch, which certainly would. Since Edison's team used to refer to lines per inch as 'pitch', i.e. 2 minute pitch or a pitch of 100 lines per inch, etc., it's easy to get confused. It totally makes sense now. Musical pitch would indeed remain constant. Thanks to you both for the clarification! I guess we should be thankful that the amount of lateral shrinkage could never exceed the amount of play in most reproducers -- more foresight from our benevolent meisterinventor, or happy accident, who knows? :-) (Is it ironic that they cut at 97tpi for manufactured playback at 100tpi, and 100 yrs later it's probably closer to 97tpi?) Best, Robert Date: Tue, 12 Jul 2011 14:30:21 -0700 From: majesticrec...@snet.net To: phono-l@oldcrank.org Subject: Re: [Phono-L] shrinking cylinder speed? This follows Robert's thoughts as well (I think). This is all about in-plane shrinkage. So the original cylinder is longer to accommodate this shrinkage and the speed at which the cutter would move laterally across the cylinder would have to be slightly faster. However, wouldn't the recording speed still be 160rpm? Glenn From: rich-m...@octoxol.com To: phono-l@oldcrank.org Subject: Re: [Phono-L] shrinking cylinder speed? The pitch of the lead screw was adjusted for shrink for linear shrink. ___ Phono-L mailing list http://phono-l.oldcrank.org ___ Phono-L mailing list http://phono-l.oldcrank.org ___ Phono-L mailing list http://phono-l.oldcrank.org
Re: [Phono-L] shrinking cylinder speed?
I think that was my original point. Shooting a flea with an atomic cannon... On 07/12/2011 06:49 PM, Loran T. Hughes wrote: All this talk of shrinkage makes me feel as if I'm in an episode of Seinfeld ;-) Spring motor, leather belt drive, and questionable tolerances do not meet the level of laser precision. Get it close, tune to ear, and enjoy. Loran On Tue, Jul 12, 2011 at 3:36 PM, Richrich-m...@octoxol.com wrote: Yes, except the 160 was not very accurately determined. Radial shrinkage after molding is not uniform either. ___ Phono-L mailing list http://phono-l.oldcrank.org ___ Phono-L mailing list http://phono-l.oldcrank.org
Re: [Phono-L] shrinking cylinder speed?
Granted. I was seeking the answer to a different question entirely. Date: Tue, 12 Jul 2011 19:00:40 -0500 From: rich-m...@octoxol.com To: phono-l@oldcrank.org Subject: Re: [Phono-L] shrinking cylinder speed? I think that was my original point. Shooting a flea with an atomic cannon... On 07/12/2011 06:49 PM, Loran T. Hughes wrote: All this talk of shrinkage makes me feel as if I'm in an episode of Seinfeld ;-) Spring motor, leather belt drive, and questionable tolerances do not meet the level of laser precision. Get it close, tune to ear, and enjoy. Loran On Tue, Jul 12, 2011 at 3:36 PM, Richrich-m...@octoxol.com wrote: Yes, except the 160 was not very accurately determined. Radial shrinkage after molding is not uniform either. ___ Phono-L mailing list http://phono-l.oldcrank.org ___ Phono-L mailing list http://phono-l.oldcrank.org ___ Phono-L mailing list http://phono-l.oldcrank.org
Re: [Phono-L] shrinking cylinder speed?
The shrink on a BA can be enough to run out of lateral travel on the reproducer before you run out of the record. On 07/12/2011 05:22 PM, Robert Wright wrote: It would indeed, Glenn! Rich's last comment helped me understand this -- one of the original questions was regarding playback rpm, so I've been thinking in terms of concert pitch, which wouldn't be affected by shrinkage, instead of lateral pitch, i.e., the lines per inch, which certainly would. Since Edison's team used to refer to lines per inch as 'pitch', i.e. 2 minute pitch or a pitch of 100 lines per inch, etc., it's easy to get confused. It totally makes sense now. Musical pitch would indeed remain constant. Thanks to you both for the clarification! I guess we should be thankful that the amount of lateral shrinkage could never exceed the amount of play in most reproducers -- more foresight from our benevolent meisterinventor, or happy accident, who knows? :-) (Is it ironic that they cut at 97tpi for manufactured playback at 100tpi, and 100 yrs later it's probably closer to 97tpi?) Best, Robert Date: Tue, 12 Jul 2011 14:30:21 -0700 From: majesticrec...@snet.net To: phono-l@oldcrank.org Subject: Re: [Phono-L] shrinking cylinder speed? This follows Robert's thoughts as well (I think). This is all about in-plane shrinkage. So the original cylinder is longer to accommodate this shrinkage and the speed at which the cutter would move laterally across the cylinder would have to be slightly faster. However, wouldn't the recording speed still be 160rpm? Glenn From: rich-m...@octoxol.com To: phono-l@oldcrank.org Subject: Re: [Phono-L] shrinking cylinder speed? The pitch of the lead screw was adjusted for shrink for linear shrink. ___ Phono-L mailing list http://phono-l.oldcrank.org ___ Phono-L mailing list http://phono-l.oldcrank.org
Re: [Phono-L] shrinking cylinder speed?
I thought that had more to do with the plaster core swelling where it wouldn't fit fully onto the mandrel. Has anyone tried those short sandpaper'd clubs they sell on eBay that are supposed to be precisely lathed to match Edison mandrels so you can bore out the inside of a swollen plaster core enough to get it to fit? $45 seems steep to me for sandpaper glued to a stick, but I've considered trying one. Robert Date: Tue, 12 Jul 2011 21:24:43 -0500 From: rich-m...@octoxol.com To: phono-l@oldcrank.org Subject: Re: [Phono-L] shrinking cylinder speed? The shrink on a BA can be enough to run out of lateral travel on the reproducer before you run out of the record. ___ Phono-L mailing list http://phono-l.oldcrank.org
Re: [Phono-L] shrinking cylinder speed?
You will find several things, the plaster swells and the celluloid shrinks. The result is that the inner profile is no longer round and it is reduced in diameter. If the record will just completely fit on the mandrel and is still round then they work. If it hangs over the end and/or is not round they do not. One end can be shrunken more than the other and teh surface may have dips and flat spots. Some of these are visually obvious and others are only detectable by ear. On 07/12/2011 09:50 PM, Robert Wright wrote: I thought that had more to do with the plaster core swelling where it wouldn't fit fully onto the mandrel. Has anyone tried those short sandpaper'd clubs they sell on eBay that are supposed to be precisely lathed to match Edison mandrels so you can bore out the inside of a swollen plaster core enough to get it to fit? $45 seems steep to me for sandpaper glued to a stick, but I've considered trying one. Robert Date: Tue, 12 Jul 2011 21:24:43 -0500 From: rich-m...@octoxol.com To: phono-l@oldcrank.org Subject: Re: [Phono-L] shrinking cylinder speed? The shrink on a BA can be enough to run out of lateral travel on the reproducer before you run out of the record. ___ Phono-L mailing list http://phono-l.oldcrank.org ___ Phono-L mailing list http://phono-l.oldcrank.org
[Phono-L] shrinking cylinder speed?
Hi all, quick question after a long absence: if a given point along the circumference of a cylinder passes a fixed position exactly 160 times per minute, why would the pitch change? Even if it shrunk to half its size, but was still played at 160 rpm, the wavelengths of the recorded frequencies in the groove wouldn't change in relation to playback time. They'd be quieter, for sure, but that's about it. It's a linear velocity system -- it's not the same as a disc record, where shrinkage towards the spindle WOULD make a difference, since the groove-to-stylus speed changes relative to diameter of stylus path. (Of course, testing that would require a shifting disc groove that would coil like a spring as the diameter decreased, an example of how theoretical physics don't always translate to a physical world.) If the cylinder's rotation was powered by a motor capstan with a rubber wheel attached to it that was in direct contact with the cylinder surface, there might be the tiniest amount of change in the speed, but at 160rpm (speaking in real-world terms here), the maximum shrinkage that would still allow a decent mandrel fit would be negligible. If we're talking about a difference in musical pitch that might render playback audibly inaccurate, I think even this example would be undetectable by even the most musical ears. I'm a career musician who has had (documented) perfect pitch for nearly 40 years, and I can only distinguish the difference between 78rpm and 80rpm (a difference of 2.5%, surely more than the average cylinder shrinkage, right?) in a direct A/B comparison, and even then with some difficulty. As a cylinder phonograph transfers its motor power to a non-shrinking mandrel and not the cylinder directly, I'm calling this a wives' tale. Best,Robert PS - 1/16 of shrinkage of a 2-5/32 cylinder comes out to a difference of 2.898%. What percent of 160rpm that would translate to in a capstan/rubber wheel-driven system is something I have no idea how to compute! Date: Thu, 7 Jul 2011 14:54:51 -0500 From: rich-m...@octoxol.com Some collectors have noticed that the Blue Amberol records shrink over time. After ~100 years this shrinkage is not insignificant. Even if the BA was recorded with exactly 160 RPM playback in mind due to this age related shrinkage the pitch is now incorrect. ___ Phono-L mailing list http://phono-l.oldcrank.org
Re: [Phono-L] shrinking cylinder speed?
There is both radial and axial shrinkage. Beyond that, how did Edison Co. determine 160 RPM? On 07/11/2011 05:20 PM, Robert Wright wrote: Hi all, quick question after a long absence: if a given point along the circumference of a cylinder passes a fixed position exactly 160 times per minute, why would the pitch change? Even if it shrunk to half its size, but was still played at 160 rpm, the wavelengths of the recorded frequencies in the groove wouldn't change in relation to playback time. They'd be quieter, for sure, but that's about it. It's a linear velocity system -- it's not the same as a disc record, where shrinkage towards the spindle WOULD make a difference, since the groove-to-stylus speed changes relative to diameter of stylus path. (Of course, testing that would require a shifting disc groove that would coil like a spring as the diameter decreased, an example of how theoretical physics don't always translate to a physical world.) If the cylinder's rotation was powered by a motor capstan with a rubber wheel attached to it that was in direct contact with the cylinder surface, there might be the tiniest amount of change in the speed, but at 160rpm (speaking in real-world terms here), the maximum shrinkage that would still allow a decent mandrel fit would be negligible. If we're talking about a difference in musical pitch that might render playback audibly inaccurate, I think even this example would be undetectable by even the most musical ears. I'm a career musician who has had (documented) perfect pitch for nearly 40 years, and I can only distinguish the difference between 78rpm and 80rpm (a difference of 2.5%, surely more than the average cylinder shrinkage, right?) in a direct A/B comparison, and even then with some difficulty. As a cylinder phonograph transfers its motor power to a non-shrinking mandrel and not the cylinder directly, I'm calling this a wives' tale. Best,Robert PS - 1/16 of shrinkage of a 2-5/32 cylinder comes out to a difference of 2.898%. What percent of 160rpm that would translate to in a capstan/rubber wheel-driven system is something I have no idea how to compute! Date: Thu, 7 Jul 2011 14:54:51 -0500 From: rich-m...@octoxol.com Some collectors have noticed that the Blue Amberol records shrink over time. After ~100 years this shrinkage is not insignificant. Even if the BA was recorded with exactly 160 RPM playback in mind due to this age related shrinkage the pitch is now incorrect. ___ Phono-L mailing list http://phono-l.oldcrank.org ___ Phono-L mailing list http://phono-l.oldcrank.org
Re: [Phono-L] shrinking cylinder speed?
Not sure, I know that 33.3rpm was determined (at random) by some readily available reduction gears that were applied to the electric 78rpm motors of the day, or so I have heard/read regarding Pict-ur-music discs -- if memory serves. I wonder how Thom came up with 160. There were other speeds as well, weren't there? I'm sure Pathe players ran at weird speeds, just because Pathe did everything kinda non-'standard', but were earlier Edisons anything other than 160? Radial and axial shrinkage would have no effect on musical pitch of a given cylinder, as the groove speed (relative to stationary stylus) would decrease proportionately with the cylinder's size; i.e., if the cylinder shrunk 3%, so would the relative groove speed, so the pitch would remain constant. As an illustration: 160rpm comes to 2.6 revs per second. If we scratched 100 perfectly spaced lines 1/8 deep along the length of a blank cylinder and played it at 160rpm, we'd hear a pitch of 266. Hz (a little bit sharp of C below middle C). If we shaved 1/16 off of its surface (or any amount shy of 1/8, actually), we'd still hear the exact same frequency by playing it back at 160rpm (albeit with less volume). In order for the pitch of a shrunken cylinder to change, the relative groove speed would have to change, and that would require the grooves to contract like a boa constrictor on its prey, and as the grooves are a part of the physical surface, that ain't gonna happen. Best, Robert Date: Mon, 11 Jul 2011 19:09:08 -0500 From: rich-m...@octoxol.com To: phono-l@oldcrank.org Subject: Re: [Phono-L] shrinking cylinder speed? There is both radial and axial shrinkage. Beyond that, how did Edison Co. determine 160 RPM? On 07/11/2011 05:20 PM, Robert Wright wrote: Hi all, quick question after a long absence: if a given point along the circumference of a cylinder passes a fixed position exactly 160 times per minute, why would the pitch change? Even if it shrunk to half its size, but was still played at 160 rpm, the wavelengths of the recorded frequencies in the groove wouldn't change in relation to playback time. They'd be quieter, for sure, but that's about it. It's a linear velocity system -- it's not the same as a disc record, where shrinkage towards the spindle WOULD make a difference, since the groove-to-stylus speed changes relative to diameter of stylus path. (Of course, testing that would require a shifting disc groove that would coil like a spring as the diameter decreased, an example of how theoretical physics don't always translate to a physical world.) If the cylinder's rotation was powered by a motor capstan with a rubber wheel attached to it that was in direct contact with the cylinder surface, there might be the tiniest amount of change in the speed, but at 160rpm (speaking in real-world terms here), the maximum shrinkage that would still allow a decent mandrel fit would be negligible. If we're talking about a difference in musical pitch that might render playback audibly inaccurate, I think even this example would be undetectable by even the most musical ears. I'm a career musician who has had (documented) perfect pitch for nearly 40 years, and I can only distinguish the difference between 78rpm and 80rpm (a difference of 2.5%, surely more than the average cylinder shrinkage, right?) in a direct A/B comparison, and even then with some difficulty. As a cylinder phonograph transfers its motor power to a non-shrinking mandrel and not the cylinder directly, I'm calling this a wives' tale. Best,Robert PS - 1/16 of shrinkage of a 2-5/32 cylinder comes out to a difference of 2.898%. What percent of 160rpm that would translate to in a capstan/rubber wheel-driven system is something I have no idea how to compute! Date: Thu, 7 Jul 2011 14:54:51 -0500 From: rich-m...@octoxol.com Some collectors have noticed that the Blue Amberol records shrink over time. After ~100 years this shrinkage is not insignificant. Even if the BA was recorded with exactly 160 RPM playback in mind due to this age related shrinkage the pitch is now incorrect. ___ Phono-L mailing list http://phono-l.oldcrank.org ___ Phono-L mailing list http://phono-l.oldcrank.org ___ Phono-L mailing list http://phono-l.oldcrank.org
Re: [Phono-L] shrinking cylinder speed?
The physical surface shrinks. This is why they were recorded at a speed different than the 160 desired final result. The actual question was how was the 160 RPM speed checked? And with an accuracy of? Or the actual mastering speed. On 07/11/2011 09:13 PM, Robert Wright wrote: Not sure, I know that 33.3rpm was determined (at random) by some readily available reduction gears that were applied to the electric 78rpm motors of the day, or so I have heard/read regarding Pict-ur-music discs -- if memory serves. I wonder how Thom came up with 160. There were other speeds as well, weren't there? I'm sure Pathe players ran at weird speeds, just because Pathe did everything kinda non-'standard', but were earlier Edisons anything other than 160? Radial and axial shrinkage would have no effect on musical pitch of a given cylinder, as the groove speed (relative to stationary stylus) would decrease proportionately with the cylinder's size; i.e., if the cylinder shrunk 3%, so would the relative groove speed, so the pitch would remain constant. As an illustration: 160rpm comes to 2.6 revs per second. If we scratched 100 perfectly spaced lines 1/8 deep along the length of a blank cylinder and played it at 160rpm, we'd hear a pitch of 266. Hz (a little bit sharp of C below middle C). If we shaved 1/16 off of its surface (or any amount shy of 1/8, actually), we'd still hear the exact same frequency by playing it back at 160rpm (albeit with less volume). In order for the pitch of a shrunken cylinder to change, the relative groove speed would have to change, and that would require the grooves to contract like a boa constrictor on its prey, and as the grooves are a part of the physical surface, that ain't gonn a happen. Best, Robert Date: Mon, 11 Jul 2011 19:09:08 -0500 From: rich-m...@octoxol.com To: phono-l@oldcrank.org Subject: Re: [Phono-L] shrinking cylinder speed? There is both radial and axial shrinkage. Beyond that, how did Edison Co. determine 160 RPM? On 07/11/2011 05:20 PM, Robert Wright wrote: Hi all, quick question after a long absence: if a given point along the circumference of a cylinder passes a fixed position exactly 160 times per minute, why would the pitch change? Even if it shrunk to half its size, but was still played at 160 rpm, the wavelengths of the recorded frequencies in the groove wouldn't change in relation to playback time. They'd be quieter, for sure, but that's about it. It's a linear velocity system -- it's not the same as a disc record, where shrinkage towards the spindle WOULD make a difference, since the groove-to-stylus speed changes relative to diameter of stylus path. (Of course, testing that would require a shifting disc groove that would coil like a spring as the diameter decreased, an example of how theoretical physics don't always translate to a physical world.) If the cylinder's rotation was powered by a motor capstan with a rubber wheel attached to it that was in direct contact with the cylinder surface, there might be the tiniest amount of change in the speed, but at 160rpm (speaking in real-world terms here), the maximum shrinkage that would still allow a decent mandrel fit would be negligible. If we're talking about a difference in musical pitch that might render playback audibly inaccurate, I think even this example would be undetectable by even the most musical ears. I'm a career musician who has had (documented) perfect pitch for nearly 40 years, and I can only distinguish the difference between 78rpm and 80rpm (a difference of 2.5%, surely more than the average cylinder shrinkage, right?) in a direct A/B comparison, and even then with some difficulty. As a cylinder phonograph transfers its motor power to a non-shrinking mandrel and not the cylinder directly, I'm calling this a wives' tale. Best,Robert PS - 1/16 of shrinkage of a 2-5/32 cylinder comes out to a difference of 2.898%. What percent of 160rpm that would translate to in a capstan/rubber wheel-driven system is something I have no idea how to compute! Date: Thu, 7 Jul 2011 14:54:51 -0500 From: rich-m...@octoxol.com Some collectors have noticed that the Blue Amberol records shrink over time. After ~100 years this shrinkage is not insignificant. Even if the BA was recorded with exactly 160 RPM playback in mind due to this age related shrinkage the pitch is now incorrect. ___ Phono-L mailing list http://phono-l.oldcrank.org ___ Phono-L mailing list http://phono-l.oldcrank.org ___ Phono-L mailing list http://phono-l.oldcrank.org ___ Phono-L mailing list http://phono-l.oldcrank.org
