Must have adjustments for an arm to be SOTA

[cdk84]

Tonearm characteristics

I enjoy your posts very much, Peter. It is clear that you listen with outstanding attention, and craft your written observations with virtually equal care for detail.

Previously, you wrote:

"I think the [SME] V has had some changes to the bearing and to the internal wiring over the years. But I am not sure of the specifics. My arm [SME V12] is based on the V but has some differences besides three extra inches. Fremer actually did not review the SME V-12. He reviewed the 312S and he did like it, but it is not as good as my arm. It is more like a longer IV than it is like a longer V."

I believe you have heard the SME IV, V and V12. Have you listened to the 312S in your system (or someone else's)? Just wonder the basis of your being able to say that the 312S is more like an elongated SME IV than like a longer V. I guess I am wondering if your opinion is based upon the 'family design resemblance' of the earlier vs. later SME arms --not necessarily incorrect, but reasonable to assert without listening experience?-- or if your opinion is audition-based.

You are very precise in the very largest part of what you write, and I wondered if this observation were founded upon experience, and if so, yours or an opinion someone shared with you?

 

[PeterA]

I enjoy your posts very much, Peter. It is clear that you listen with outstanding attention, and craft your written observations with virtually equal care for detail.

Previously, you wrote:

"I think the [SME] V has had some changes to the bearing and to the internal wiring over the years. But I am not sure of the specifics. My arm [SME V12] is based on the V but has some differences besides three extra inches. Fremer actually did not review the SME V-12. He reviewed the 312S and he did like it, but it is not as good as my arm. It is more like a longer IV than it is like a longer V."

I believe you have heard the SME IV, V and V12. Have you listened to the 312S in your system (or someone else's)? Just wonder the basis of your being able to say that the 312S is more like an elongated SME IV than like a longer V. I guess I am wondering if your opinion is based upon the 'family design resemblance' of the earlier vs. later SME arms --not necessarily incorrect, but reasonable to assert without listening experience?-- or if your opinion is audition-based.

You are very precise in the very largest part of what you write, and I wondered if this observation were founded upon experience, and if so, yours or an opinion someone shared with you?

Thanks, cdk84. I have owned the SME 309 (rebadged for the Model 10A), the V and the V-12. I have not heard either the SME IV or 312S in my system, though I have heard the 312S at a show. My comments are based on the list of features, where they are positioned in SME's tonearm lineup, and by what I read in the Fremer review of the 312S and from listening and using my V-12. I also gathered information by reading their feature list and specifications on the SME website. It was clear that once the 312S and Model 20/12 were released that a 12" version of the V arm and a Model 30/12 would follow with better sound and higher prices as flagship products.

As to specific differences, the IV and 312S do not have dynamic VTF while the V and V-12 arms do have this feature. This seems to be the most obvious physical difference and why I grouped the IV and 312S together and the V and V12 together. I have found dynamic VTF to be an important difference, particularly with warped LPs. The bearings may also be slightly different, as well as the internal wiring, but I could not find specific information on their website. The motor controllers, bearings and wiring of some SME turntable and arms have changed over time, but the website does not go into details.

I have not directly compared the 312S to the V-12, but I spoke extensively to Albert Porter who owned both arms and did a serious comparison. I think the general consensus is that the V-12 is superior to the 312S, even though the latter does have a removable headshell which facilitates azimuth adjustment.

 

[Don C]

Here is my rebuttal to Peter A. We both have different experiences, and think highly of the sound we get at home.

I do not live in “greater” Boston, or own a large sailboat, or have more than a million bucks in net worth.

I have referenced the experience of others like John Curl, and the author of the 1982 Audio Magazine article, who originated the 92 degree stylus angle theory. I have also heard the Shrive -Rabco arm demo, in a store, in the 70’s, that first demonstrated the 5 minute angle change, showing a dramatic sonic change, evident to anybody with normal hearing. This was in Milwaukee, where Dr. Shrive was a mathematics professor at UW-Milwaukee, and started the whole SRA thing.

The adjustment of the SME arms like the SME V12 (which is a longer SME V) and a basically unchanged arm design, since 1987, when the V was first sold, can not be adjusted to get within the 5 minute SRA angle. As a result you can not experience the sonic changes documented in the late 70’s and early 80’s.

You feel you get “Sublime” sound from a 2 way box speaker, on stands, with no low bass down to 30 hz, or high frequencies up to 40 Khz, like I get with my lowly Magnepans. My experience of tiny speakers on stands, are "midgets suspended in air".

We have TOTALLY different experiences. We both like what we have. So be it.

If you can not get into the 5 minute SRA “window” you will never experience the dramatic sonic improvement. That is a fact. It is also the opinion of the Audio Magazine author that once the optimal 5 minute SRA angle is set, 80% of records played (without any changes to arm settings)
will yield sonics close to the optimal. Believe that or not. I do not care. Read my Links.

I was just outlining my systematic approach to get the best out of my arm.

Have a nice day.

 

[PeterA]

Don, If my math is correct, the SME V-12 can be adjusted to 5 minutes of a degree for proper SRA:

1 minute of a degree = 1/60 of a degree
5 minutes of a degree = 5/60 = 1/12 of a degree
a 9" tonearm raised 4 mm changes the SRA 1 degree
4mm = 1 degree
1mm = 1/4 degree
1/2 mm = 1/8 degree
a 12" arm raised 4 mm changes SRA < 1 degree
1/2 mm < 1/8 degree, closer to 1/12 of a degree or 5 minutes SRA angle.

I adjust my arm between 1/2mm and 1/3 mm for each of my LPs which is about 5 minutes of one degree of SRA. This is easily done with the V-12 using only the scale printed on the paper protractor provided by SME with all of its arms. And I have demonstrated how it is done and what the sonic results are to four fellow WBF members, and others.

I agree with you that differences in SRA of this magnitude are fairly easily audible and can make a big difference to one's listening pleasure because of the dramatic sonic improvement. I do happen to think that there are other arms which do make it easier to adjust VTA in a precise and repeatable manner - the Triplanar, the Graham, the Durand Talea II for example. But it is certainly possible to do with the SME V-12 if not as convenient as some other arms.

Incidentally, I grew up in the Midwest and learned how to sail scows on Lake Geneva in Wisconsin, perhaps not far from where you live. If you ever find yourself in the Boston area, I invite you to the North Shore for an afternoon of sailing and an evening listening to LPs.

 

[Don C]

OK, point well taken about getting to a 5 minutes SRA. However can you move within the 5 minutes angle and hear the dramatic changes?

The demos and evidence of the 5 minute angle, is the ability to move around the 5 minute SRA, requiring a finer adjustment than 5 minutes.

And as I alluded to, I also believe their are multiple sonic peaks, with a master peak showing the greatest change, and minor peaks, to each side of the master peak. These multiple peaks are evident in mechanical resonance theory. How do you know if you are on the master peak?

The peak is very small, and you need to move within the 5 minutes, to get hear full extent of sonic changes.

Also the Audio article author believes, as I do, that once the optimal SRA is found, 80% of LPs played will sound very close to perfect. I do not feel that you experience or believe that. That is why I set the "mean" optimal SRA for the 80%, and do not bother adjust each Lp.

You have to listen to multiple records, before finding the mean optimal SRA.

Try this experiment - after finding your 5 minute SRA, adjust the tracking force in small steps (measuring with an electronic scale to a thousandths of a gram). This will allow you to move around the 5 minute SRA. See if you get even more dramatic sonic changes.

Maybe this is splitting a hair multiple times, but I believe my method zeros in on the "true" optimal SRA, and agrees with the referenced links, and the Shrieve-Rabco demo that I heard in the 70's.

If in Boston I will take you up on your sailing offer. I sailed on lake Mendota, in Madison, Wisconsin back in the 70's while at the university.

Cheers!

Don C.

 

[Don C]

Further thoughts.

I believe I have outlined the essential arm adjustments, but remember:

listen intently to many lps, and make very small adjustments.

The closer you get to the perfect setting, the greater the sonic change.

These various adjustments interact with each other.

This is an iterative process, and takes time.

Think about what each adjustment does to the alignment of the diamond in the groove.

There are variations in the cutter head during the making of the recording, but they use a microscope for adjustment, and the good recordings are similarly cut.

The end result is: An overall improvement in playback, that may bring out deficiencies present in many Lps, but also an improved ability to recognize differences in sound quality from Lp to Lp.

If you think my turntable setup is "Run of the Mill" good, watch this video of the Audio Research tour in 2016, and you will see the exact same setup in their listening room. They would use only the best!

http://www.analogplanet.com/content/analogplanet-visits-audio-research-corporation

 

[XV-1]

What about tangential tracking ?

 

[Don C]

No horizontal alignment method will yield zero tracking error from the beginning to the end of a record side.

Do you want minimum average error across the record, absolute minimum error in the middle, or minimum error at the end where there is most likely an error peak?

That is why there are different methods, however none are perfect.

Try the alignment gauge that came with your arm first. Do you hear mistracking?

If so try another gauge. I like the VPI gauge that came with my arm, and hear no audible mistracking, even near the end, on any of my 2000 Lps.

I tried a few others, but they were not better than the VPI.

 

[XV-1]

Who is talking about mistracking? I have never heard mistracking when my cartridge and tonearm has been aligned to spec.

This is about tracking error and what gets closest to the original tangential cutting of a record.


Is 0.0006 % maximum tracking error across the entire lp good enough?

http://www.tonarm.ch/de/technology#Geometry Thales Simplicity

 

[Don C]

I do not believe that! All the way across the record?

The stylus vibrates in three dimensions anyway, super small errors are not audible in relation to other issues. like the stylus not perfectly mounted on the cantilever or diamond grind error.

The author is splitting theoretical hairs, that do not matter in real life. Nothing is perfect.

The cutting is with a straight line tracking cutter, and there is no theoretical tangential error.

Read this: http://www.vinylengine.com/vpi-tonearm-geometry.shtml

 

[XV-1]

I do not believe that! All the way across the record?

The stylus vibrates in three dimensions anyway, super small errors are not audible in relation to other issues. like the stylus not perfectly mounted on the cantilever or diamond grind error.

The author is splitting theoretical hairs, that do not matter in real life. Nothing is perfect.

The cutting is with a straight line tracking cutter, and there is no theoretical tangential error.

Read this: http://www.vinylengine.com/vpi-tonearm-geometry.shtml

I well versed with VPI. I owned a HRX for 6 years - nice table and the VPI alignment does sound best as that is the alignment that Harry designed his tonearm with.

and you don't believe that 0.0006 tracking error cannot be across the record with a different tonearm with tangential tracking.

I guess one does don't know what one does don't know.

 

[Don C]

Look up the Garrard Zero 100 arm from the 70's.

Your HRX arm was probably not optimally adjusted. The HRX turntable has issues besides the arm IMO.

I know what I hear, and I hear no audible issues!

Go climb a tree!