|
Vinyl Asylum: RE: I agree with Baerwald being mathematically attractive, but... by John Elison Welcome Licorice Pizza (LP) lovers! Setup guides and Vinyl FAQ. |
For Sale Ads |
75.90.147.196
In Reply to: I agree with Baerwald being mathematically attractive, but... posted by travisty on May 2, 2011 at 03:16:58:
> On a practical basis however, if one has standard mounting distance according to a standard IEC template,
> the EFFECTIVE best alignment for any given record made in the past 25yrs could easily be Löfgren B because so
> many of them have their last modulated groove radius even before the Baerwald inner null point.
The problem I'm having is how to address this sort of misunderstanding and misrepresentation of alignment methodology. The alignment terminology labeled Löfgren, Baerwald, Stevenson, etc., is not a terminology based on a specific set of null-points but on a specific set of beginning and end points for the modulated groove area. When you say that you believe that Löfgren B might be the better alignment because "many LPs have their last modulated groove radius even before the Baerwald inner null point," you demonstrate a misrepresentation and a misunderstanding of alignment methodology. An LP can never have its last modulated groove radius occur before the Baerwald inner null point. The definition of Baerwald, which we now call Löfgren A, always places the inner null-point well inside the modulated groove envelope. Only Stevenson's alignment has its inner null-point coincident with the innermost modulated groove.
For example, if you have Löfgren's A alignment with null-points at 66-mm and 121-mm and you switch to an LP with its innermost modulated groove at 66-mm, your alignment is no longer Löfgren's "A" alignment. Now it becomes Stevenson's alignment. Therefore, you need to be talking about specific alignment null-points instead of mislabeling them Baerwald, Löfgren, or Stevenson. Your concern is that the inner null-point should be placed at a specific point in order to achieve the best compromise for the vast majority of LPs.
My point is that if you do not want to compromise your alignment you should measure the beginning and ending groove radii of each LP and realign your tonearm for Löfgren's "A" alignment for each individual LP. This is because Löfgren's A alignment produces the lowest overall distortion compared to any other alignment methodology. On the other hand, if you want to compromise and select a permanent set of null-points, the label you place on them (Löfgren, Baerwald, Stevenson) will actually change with each LP you play depending on its innermost and outermost groove radii.
> Stevenson null points are not generated off groove radii like the Löfgren A & B are.
Not true! Stevenson's alignment is simply Löfgren's "A" alignment with the inner null-point at the innermost groove. In other words, Stevenson's alignment minimizes tracking error distortion across the modulated groove envelope with the caveat that the inner null-point must be coincident with the innermost groove. For example, suppose you had an innermost groove radius of 54.8-mm and outermost groove radius of 146.05-mm. Löfgren's "A" alignment would yield null-points of 60.325-mm and 117.42-mm. These are also Stevenson's null-points for an innermost groove of 60.325-mm and outermost groove of 146.05-mm.
The truth of the matter is that everyone who came after Erik Löfgren simply reproduced Löfgren's equations in slightly different form. There is really nothing new in tonearm alignment since Professor Erik Löfgren published his original paper in 1938.
Best regards,
John Elison
This post is made possible by the generous support of people like you and our sponsors:
Topic - REVIEW: UNI-Protractor UNI-Protractor Tone Arms - Stitch 07:20:07 04/30/11 ( 26)
- * NEW * UNI-P2S Precise Adjustment Pivot to Spindle - Stitch 10:58:14 08/19/11 ( 0)
RE: REVIEW: UNI-Protractor UNI-Protractor Tone Arms - Mel 09:37:44 05/1/11 ( 15)
- RE: REVIEW: UNI-Protractor UNI-Protractor Tone Arms - John Elison 11:54:53 05/1/11 ( 14)
- RE: REVIEW: UNI-Protractor UNI-Protractor Tone Arms - Mel 13:28:10 05/1/11 ( 1)
- RE: REVIEW: UNI-Protractor UNI-Protractor Tone Arms - John Elison 14:23:28 05/1/11 ( 0)
- RE: I like the magnifier - user510 12:45:21 05/1/11 ( 11)
- RE: I like the magnifier - John Elison 14:15:35 05/1/11 ( 10)
- Precision of alignment - Paul Tobin 17:59:25 05/1/11 ( 2)
- RE: Precision of alignment - p.taylor 00:06:14 05/2/11 ( 0)
- RE: Precision of alignment - John Elison 23:25:15 05/1/11 ( 0)
- For you, would there be any reason to prefer lower distortion OUTSIDE the nulls - travisty 17:13:19 05/1/11 ( 4)
- RE: For you, would there be any reason to prefer lower distortion OUTSIDE the nulls - John Elison 18:31:15 05/1/11 ( 3)
- I agree with Baerwald being mathematically attractive, but... - travisty 03:16:58 05/2/11 ( 2)
- RE: I agree with Baerwald being mathematically attractive, but... - John Elison 05/2/11 10:56:44 05/2/11 ( 1)
- Thanks for correcting me on Stevenson - travisty 17:35:45 05/2/11 ( 0)
RE: one thing about null points.... - user510 15:15:38 05/1/11 ( 1)
- You can also move null-points without altering effective length or mounting distance by changing offset angle. /nt\ - John Elison 16:50:53 05/1/11 ( 0)
RE: REVIEW: UNI-Protractor UNI-Protractor Tone Arms - JCF 06:36:55 05/1/11 ( 0)
RE: REVIEW: UNI-Protractor UNI-Protractor Tone Arms - Halcroman 22:39:04 04/30/11 ( 0)
RE: REVIEW: UNI-Protractor UNI-Protractor Tone Arms - FolkFreak 13:50:47 04/30/11 ( 0)
nice post, thanks - beach cruiser 13:48:35 04/30/11 ( 0)
Kudos for your photography! - Muzikmike 10:40:10 04/30/11 ( 0)
RE: REVIEW: UNI-Protractor UNI-Protractor Tone Arms - bjh 09:48:36 04/30/11 ( 1)
- He produced a limited edition about 20yrs ago called the Apolyt - travisty 10:02:08 04/30/11 ( 0)
Thanks for that informative review! - user510 09:05:37 04/30/11 ( 1)
- The origin is apparently a 1984 article from German magazine 'Das Ohr' - travisty 09:59:32 04/30/11 ( 0)
RE: REVIEW: UNI-Protractor UNI-Protractor Tone Arms - mosin 08:41:51 04/30/11 ( 0)