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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
128x128dougolsen
dan_ed
2,451 posts
 
Hiho, I am sorry. I have read your last two post several times and I cannot grasp what it is you are saying about bearing angles and AS and VTA. Can you explain that in simple terms?
lewm
12,454 posts
 
Essentially, I think Hiho is saying that to adjust azimuth without altering VTA, the adjustment must be made downstream from the ~23 degree offset angle that is typically built into the geometry of fixed bearing tonearms. (It's not always 23 degrees; I own two tonearms, the Kenwood L07D tonearm and the Dynavector DV505 where that angle is less than 23 degrees.) If you adjust azimuth by twisting the arm upstream from the bend, then you are also changing VTA. Is that correct, Hiho?

Never having seen any of the tonearms Hiho mentions as exceptions, I don't readily understand how they work, unless the headshell itself twists about its own axis, as in the case of a removable headshell with built-in azimuth adjustment capability. The newer Reed tonearms also avoid this issue by allowing azimuth adjustment right at the headshell, but this adds several grams in terms of effective mass.
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.

______
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