Record’s physical design properties


Can someone describe or point me to a document that describes the physical properties of records in terms of the shape of the grooves and how the shape, weight, or the overall design of a cartridge affects the sound and in particular the bass and treble response. Visually speaking, in some songs the grooves are tighter and deeper and in others they are further apart and appear shallower and these differences definitely sound different. Just very curious.
 Thanks in advance.
Dfc79476 b7e2 448b 8f7b 3aed2a5e9ad4kalali

Hi, kalali,

Here are two web pages that include "Personal Notes on Record Specifications". (I’m not exactly sure who the author is.)

http://www7a.biglobe.ne.jp/~yosh/recspecs.htm

http://www7a.biglobe.ne.jp/~yosh/vta.htm

The pages are somewhat difficult to read through but contain a lot of information and history. You won’t find all the answers to your questions but it’s a good reference.

There's also this web site: http://www.recordcollectorsguild.org/modules.php?op=modload&name=sections&file=index&req=viewarticle&artid=44&page=1

Regards,

Tom

kalali, here's another web page: "The Genesis Of Vinyl Stereo Record". English version is along left side of page.

http://www.badenhausen.com/VSR_History.htm#Appendix_A

Tom

Thank you all. What piqued my curiosity was I noticed by accident that I could tweak the sound by changing the counterweight - more weight on the cartridge. Not saying dramatic difference but the bass in particular was noticeable. It made me think that the shape of the grooves and the depth that the needle travels through them affects the frequency response.

Ah, ha; a vinyl tweak that worked. ’-)

The shape of the groove is determined by the cutting lathe stylus so there is a specific stylus alignment that best traces that cut. The alignment of the stylus in the groove is determined by a combination of several parameters, such as VTF, SRA, azimuth, and even anti-skate.

The thing about tonearms and cartridges is that if you make a change in one parameter, like VTF, it affects other parameters, like SRA and can also affect the signal generator in the cartridge. So when you do make a change, you have to consider the other ways you could achieve the same alignment in the groove or could affect the generator in the cartridge. You added VTF, which caused the cantilever to take on more force and change angle, which caused the stylus to ride in the groove at a different SRA. But it may have also changed the alignment of the cantilever in the signal generator of the cartridge.

For example, instead of adding VTF, try keeping the VTF the same, but lower the tonearm base so the cartridge tilts back just a bit and realigns the angle of stylus (SRA) in the groove, similar to the SRA you’d get by adding VTF. You may or may not hear the same difference in sound.

You could also change the angle of the cantilever in the cartridge body by adding VTF but keep the SRA the same by raising the tonearm base. By having the same VTF for different SRA alignments, you’ll be hearing more of the affect of SRA. If you don’t hear much difference, then the additional VTF is probably affecting the cartridge’s signal generator and producing the difference in sound.

That’s the fun of this hobby.

Regards,

Tom

Not only what tketcham wrote, but also keep in mind that moving the CW also changes tonearm effective mass, which can have an effect on bass response if the resonant frequency is near to being too high in the first place.  (The position of the CW with respect to the pivot affects effective mass according to the square of the distance between the center of mass of the CW and the pivot point.)  So, a little movement of the CW can have a large effect.  I am curious; what motivated you to arbitrarily move the CW (presumably toward the pivot which would increase VTF)?
“what motivated you to arbitrarily move the CW (presumably toward the pivot which would increase VTF)?”

It was by mistake. I switched cartridges between two turntables and made an error when resetting the the tone arm/cartridge to 0 and then adjust by adding the specified cartridge weight. 
Thanks tketcham for your explanation and everyone for providing the links.
Lots of moving parts that need to come together to make good sound.