Confused: Cutting angle

[Sillitoe]

[Sillitoe]

VMS80 looking very much like B.
Source http://www.taloowa.com/

1.jpg

Cheers
James

[jesusfwrl]

Hmmm... I do not know much about the VMS80, but I was recently told by someone experienced, how the VMS82 (DMM) was made to work with a vertical angle of cut. I had nightmares ever since.

It could be that the VMS80 had already adopted this system, or it could be a VMS82 converted to a VMS80? I guess only the Taloowa crew would know the answer. But for the VMS82, it doesn't just simply work at 0 degrees.

I disagree regarding cuts intended to sound good on a particular setup. I do not own an SL 1200, I do not play in clubs and I do not really listen to electronic music much. I have set up my turntables as close to the standards as possible, and mostly listen to rock/blues/jazz/classical music. I recently received opcode66 From Dark to Light/Dream About record, which sounded extremely good on my systems. Judging by the style of music I assume it was also intended to sound good on an SL1200 in a club. Conversely, a friend who is a DJ and has an SL1200 setup for the club, listens to a lot of jazz at home on it and it sounds just fine. A good cut should translate well across a variety of different systems, as long as all the systems follow the same general principles and standards.

There is also a lot more to cutting angles than distortion due to VTA mismatch. As an example, the cutting stylus is designed to give a particular groove geometry (lets say 90 degrees) at a certain angle of cut. Changing this angle of cut will no longer produce a 90 degree groove. If a particular cutting stylus was designed to cut at 15 degrees, if used vertically, the shape of the groove would be different to the one originally intended. However, a cutting face cutting at a digging angle is very likely to cause a variety of problems along with the mechanical time constant of the suspension, unless it is tuned perfectly. So, it is important that the stylus is designed for the task, and that it is used according to the design intentions. The desired angle of cut consideration still applies on top.

[jesusfwrl]

Detailed drawings of cutting styli can be found from the original manufacturer documentation in Basic Disk Mastering.

Not sure if they are up to date with current production, but it should give you an idea of the geometry, and why this would shift if the stylus is tilted.

[Sillitoe]

Some good stuff here

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

I love the last part of the article...

"There are various kinds of audience imaginable about the actual effects of tweak or adjustment:

1.One cannot perceive the effect and express it frankly.
2.One cannot perceive the effect but keep silence or pretend to hear the effect as in the case of "The Emperor's New Clothes" (audiophiles or readers have often fixed idea or taboo or culture influenced by books and other sources).
3.One can perceive the change of sound, but cannot attribute it to a specific reason since actual sound results from the compound of various distortions or complex reasons.
4.One can perceive the change of sound and attribute it to a predetermined reason.
In vinyl reproduction I feel group 3 is most common. I find there is no difference between group 1 & 4 actually when the change of sound is small. Every analog system sounds different each other. There is no objective index in personal appreciation."

Cheers
James

[Sillitoe]

SX74 also on VMS80.
https://instagram.com/p/5XVZtqLfDS/

Another.
https://www.instagram.com/p/5-UdANDtm7/

Cheers
James

[chris-zwarg]

Sorry to resurrect a 9-year-old thread, but after reading it I am still confused as I find many answers yet no answer....
I am looking at this page, with wording similar to several ancient (1950s) manuals for "cutting records at home" (e.g. by Fritz Kühne)

https://www.myshank.com/fr/content/6-faq

The page talks of recommended angles of 10°, 12°, and 5-6° for various types of blanks. I understand that 0°is vertical, but is that 10°etc. digging angle (C in the illustration up this thread) or raking angle (A in that illustration)? Both from very old amateur literature and (limited) own experience with an old mono 78rpm cutter with steel styli I gather that with that ancient technology you wanted a raking angle (like a gramophone needle, only steeper), and it was recommended to make it as steep (close to 90°) as it will go without the stylus uncontrollably digging into the surface and ruining both stylus and blank - I've had that happen on the old machine when I tried to set the head "beyond vertical" to a digging angle: It started vibrating, jumping up and down, eventually driving the stylus tip through the lacquer into the aluminium base, instantly destroying the tip! I've been restoring the motor, amp and Neumann 12c head so my old machine should be ready to go cutting some PVC, but I really don't trust the quoted angles unless I am really sure what is meant. Simply can't afford to lose a 200+ € diamond-tip stylus to a misunderstanding!

[markrob]

Hi,

I think you have it right. You don't want the stylus to dig into the material. That would cause tool chatter not unlike you would find on a metal lathe. Vertical or a slight tilt back is what is needed. If you are embossing, you generally tile back a bit further to make sure you do not transition from embossing to cutting.

Mark

[Thelatheofus]

When cutting into plastic your needle should be "digging" into the plastic because plastic has a spring back effect (it will want to go back to its original shape after cut, in the opposite direction of the cut)
To counter that you need to cut with a "digging" tilt, so once the spring back effect takes place your groove will have the desired shape.
It is different for every plastic because they all have different spring back effects.

[Discomo]

An interesting discussion. However, let’s not forget to just use our ears. By simply trying out the different possibilities you’ll find the sweet spot. In the end, the ears never lie.