Baerwald? LofgrenB? Stevenson? The math behind alignment conventions

[JimmyJet]

@miglto Yes, thanks - those are IEC, I’m specifically looking for the DIN version of those null points.

 

[mtemur]

Since we’re talking IEC null points here, would any of you happen to know what the DIN null points are for Lofgren A & B? I’ve looked on line and haven’t come up with anything - I would think there’d be a chart somewhere listing all the null points for all the different geometries for every standard, e.g., IEC, DIN, JIS, etc. Please let me know if you have a source -thanks

Here are null points (last 2 lines) for 12" record DIN radiuses (first 2 lines). You can check my prior posts on this thread for JIS.

 

[mtemur]

@miglto Yes, thanks - those are IEC, I’m specifically looking for the DIN version of those null points.

Good luck on explaining that.

 

[JimmyJet]

Here are null points (last 2 lines) for 12" record DIN radiuses (first 2 lines). You can check my prior posts on this thread for JIS.
View attachment 118280

View attachment 118281

@mtemur Thank you!

 

[miglto]

In my experience it is useful to find good alignment targets but that is only the starting point. Most cartridge’s styli are not exactly square with the cantilever and/or body, and for this reason, once you have done a good alignment you need to fine-tune zenith (and azimuth) to get the best setup.

I use AnalogMagik for this but there are other methods including listening for distortion which work well.

 

[Robert Young]

Good luck on explaining that.

Really not sure where all the attitude is coming from, but it has been quite unpleasant throughout this thread.

 

[theophile]

Please excuse me if this has already been posted:

rca :: Radiotron Designers Handbook 1954 : Free Download, Borrow, and Streaming : Internet Archive

From the bitsavers.org collection, a scanned-in computer-related document.rca :: Radiotron Designers Handbook 1954

archive.org

 

[mtemur]

Really not sure where all the attitude is coming from, but it has been quite unpleasant throughout this thread.

Sorry to hear that sensibly warning a member is unpleasant to you.

 

[Robert Young]

Sorry to hear that sensibly warning a member is unpleasant to you.

Treating a different member with such animosity as you continually display to miglto is unpleasant and unnecessary.

 

[mtemur]

Treating a different member with such animosity as you continually display to miglto is unpleasant and unnecessary.

Please add IMHO to your post cause it only reflects your opinion.

IMHO your jumping in with a judging style is unnecessary and unpleasant.

 

[Robert Young]

Please add IMHO to your post cause it only reflects your opinion.

IMHO your jumping in with a judging style is unnecessary and unpleasant.

IMO this isn’t about style, and IMO you are completely aware of that.

 

[miglto]

Please excuse me if this has already been posted:

rca :: Radiotron Designers Handbook 1954 : Free Download, Borrow, and Streaming : Internet Archive

From the bitsavers.org collection, a scanned-in computer-related document.rca :: Radiotron Designers Handbook 1954

archive.org

Really interesting. Anyone has a link to the full pdf of the book (it is at this point public domain).

 

[theophile]

Really interesting. Anyone has a link to the full pdf of the book (it is at this point public domain).

The entire book is available in that link I posted. Otherwise there were lots of PDF versions on the net.

 

[miglto]

The entire book is available in that link I posted. Otherwise there were lots of PDF versions on the net.

Thx. Did not realize there was a download option. I downloaded from this link, this book is amazing. Thank you!

 

[Kingrex]

I have looked at these on my protractor never knew how they differed. I understood they meant the 2 null points were different. But, is there any reason any, either, or would sonically sound different. Or are the sonics only impacted by the geometry of the diamond tip to vinyl surface contact. The null points only being where rhe diamond at 2 points has its Zenith correct to the groove.

 

[mtemur]

I have looked at these on my protractor never knew how they differed. I understood they meant the 2 null points were different. But, is there any reason any, either, or would sonically sound different.

Almost all pivoted arms have overhang and offset at the headshell. This design choice reduces tracking error by enabling two tangential radiuses over the record surface. Those are called null points. Each geometry whether Lofgren A, B or Stevenson has a different approach at handling distortion. Depending on your choice of geometry distortion level is going to change which will inevitably effect the sound.

Most common geometry, the Lofgren A (Baerwald) aims to achieve equal distortion levels at the beginning, at the end and in between the null points. The location of null points depend on design approach of the geometry and inner and outer groove radiuses of the record. In other words working area. Each standard (IEC, DIN, JIS) defines this working area differently by agreeing on different inner and outer groove radiuses. That's why location of null points is determined also by the standard. The same Lofgren A alignment dictates different location of null points for IEC, DIN and JIS. It is still the same design approach set by Lofgren A but different null points. Changing location of null points becomes possible by altering overhang and offset angle.

As a result each geometry and standard has a different location for null points which makes it 9 in total. You can invent another design approach and settle on a different location of null points just like UNI-DIN. It concentrates only on DIN standard raising total choices to 10. All of these 10 choices inevitably effect the sound. As if it's not complicated enough you can measure your record collection and set your standard for inner and outer groove radiuses which will dictate new location for null points depending on the geometry you've chosen. Which choice is better is up to you.

If you have a record collection cut regarding IEC standard then settling on IEC Lofgren A is most probably better than DIN Lofgren A, but it's not certain if it's better than IEC Lofgren B or IEC Stevenson.

Or are the sonics only impacted by the geometry of the diamond tip to vinyl surface contact.

No. Sonics are impacted by both geometry of the stylus relative to groove (zenith, azimuth, SRA) and geometry of the arm relative to grooves (overhang, offset)

The null points only being where rhe diamond at 2 points has its Zenith correct to the groove.

Yes, if you set zenith correctly. Zenith is more related to cartridge alignment than geometry.

 

[Kingrex]

Ouch. A lot to digest. One of my favorite settings is with a paper tractor I made with photo paper. It came from a Rega download I calibrated, then punched out the center with a pin. I don't know what its based upon, but I like it with my table. Never really gravitated to anything on my Smart Tractor.
Thanks for the info.

 

[mtemur]

Rega protractors are usually IEC Stevenson.

 

[Kjetil]

An anecdote (I may have posted it before, and if in this thread way before the off topic discussions):
I measured the innermost modulated groove radius of the by now well documented side three of the DG TOS release of the Brahms piano concertos with Gilels and Jochum to 52 mm. Putting that into a Löchern A/Baerwald calculator I got 57.5 mm as the inner null, the same as Stevenson DIN.

 

[mtemur]

An anecdote (I may have posted it before, and if in this thread way before the off topic discussions):
I measured the innermost modulated groove radius of the by now well documented side three of the DG TOS release of the Brahms piano concertos with Gilels and Jochum to 52 mm. Putting that into a Löchern A/Baerwald calculator I got 57.5 mm as the inner null, the same as Stevenson DIN.

Cutting engineers don’t always conform to the standards and cut longer even in the country that set the standard. This makes it even more complicated.