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Azimuth observations and importance

After adjusting azimuth with a Fozgometer loaned to me, the following is what I observed. Individually, these changes were subtle although noticeable. The combined effect however, was significant to the overall presentation.

Imaging improved.

Vocals became more focused, not as big and wide as before.

Instruments more detailed with greater air. Location is more precise.

Tighter bass versus the slightly lingering bass notes previously.

Better top to bottom detail and clarity.

I never realized how important correct azimuth adjustment is and this exercise was quite a learning experience for me. Thinking I was correctly adjusting azimuth by visually setting the headshell as level as possible was a reasonable but flawed attempt.

I have found at least two stylus issues that if present will affect azimuth and sound.

1) A straight cantilever that is twisted left or right changes the attitude of the diamond and its relationship to the groove. By twisted I mean the cantilever has rotated on its own axis. This one is very difficult to see without appropriate magnification.

2) A cantilever that is canted to the left or right a degree or more but is still straight, not bent. It points left or right probably because it was not centered correctly when the cantilever was installed. It also changes the attitude of the diamond.

What is probably basic and common knowledge to everyone here is something I have just been enlightened about after giving it very little thought. I am now convinced that accurate azimuth is a required step in the turntable set up process and I will be giving full attention to this part of the equation.

No more guesswork and eyeballing which I am embarrassed to say was the norm. Doug
dougolsen
dan_ed
2,451 posts
 
I think I see. If it is what I'm thinking then Hiho's premise would apply to fixed bearing arms that also cant the headshell. Nothing new here. Even so, the fact that there is a small range for either adjustment to be made without significant change to the other parameter should be known by the user of the tonearm.

I recently spend a few weeks with new tonearm prototype that has true on-the-fly azimuth adjustment. This really makes setting AZ correctly by ear a no brainer. I found that, like VTA, many albums that I play seem indifferent to AZ tweaking. For others it is like that cheesy Bose commercial where the picture of the tiny system grows into a much larger one. The sound presentation change was very much like that when AZ was correct.
dougdeacon
3,338 posts
 
Doug,

Congratulations on advancing to "adjusting by listening", and on learning to hear the difference azimuth adjustment makes.

Like Teres I used to use electronic equipment to adjust azimuth. After sessions with several cartridges I realized I could adjust just as accurately while listening to music, not to mention faster and with less fuss. You described EXACTLY what to listen for, IME.

Good that you discovered levelling the headshell doesn't help much. No one plays grooves with a headshell, we play them with a stylus and few styli are vertical to the necessary degree of accuracy. Levelling the headshell's usually a time-wasting distraction. Roughing in by eye is best done by making the stylus look vertical with a mirror and magnifier. After that the fine tuning is by ear and the headshell ends up wherever it ends up.

VTF, VTA/SRA and antiskating are also all best adjusted by listening to music. The more practiced we get the fewer measurements and test records we need.

Good post,
Doug

P.S. Hiho is correct. I described his observation by analogy many years ago on VA. Azimuth changes with vertical arm angle on any tonearm with an offset headshell. It's unavoidable.
hiho
451 posts
 

As I said, approximately 23 degrees for typical Rega 9 inch arm and offset angle decreases as the arm gets longer. Lewm is right that azimuth can be adjusted at the headshell on its own axis. However, not many tonearms allow azimuth adjustment at the pivot area WITH the offset angle built in; that's why I dropped those few names.

Don't worry, this is not a knock on arms that don't have this feature as long as you pay attention to adjustment and can get good result and that's all that matters. Enjoy the music.

______
hiho
451 posts
 

I think a close study of the Graham Phantom will explain this geometric issue better. Sorry for being so clumsy at explaining in writing.

Notice the bearing angle to the azimuth adjuster on the "magnaglide". This angle matches the angle at the headshell so when you change the azimuth of the pivot, the azimuth of the cartridge changes with it. (I know the Phantom is a quasi-unipivot so it requires outside support to avoid azimuth rocking)

Top view:
http://ic2.pbase.com/o4/06/530506/1/53878804.GraBal3.jpg

Side vide:
http://www.graham-engineering.com/db3/00271/graham-engineering.com/_uimages/Phantom20II20Magnet.jpg

_____
essentialaudio
1,147 posts
 
Guinness wrote:
Michael Fremer reviewed just such a product - Dr. Feickert's Adjust+ in Stereophile's Oct. 2008 issue. Mikey liked it, conditionally. The manual was poorly translated from the original German. When/if the manual was re-written in plain English, he'd highly recommend it. Unfortunately, it doesn't seem to be in their web archives.

The article mentioned the cost was $250 with a Pro version available at $399. It measures phase angle, crosstalk, speed, wow, flutter, S/N, harmonic distortion, tonearm resonance and frequency response using a test LP (included) and high quality sound card (not included).
The better translated manual was available by the time Fremer's article was published.

The prices are in Euros, not dollars, so the cost is quite a bit more. The pro version which I use on clients' systems measures all those parameters, while the standard version does not but includes the azimuth measurements.

With regard to azimuth, the Feickert software measures phase response and crosstalk. The former correlates better to what we hear and the transfer function is used to determine it.

Because I get phone calls and emails asking if I sell the software, I should clarify that it is only sold direct.
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