In audiophile circles, the topic of azimuth adjustment has long been a bit of a mystery. It's unfortunate because it is a parameter that is just as important as the tracking force if you want to get the maximum performance out of any cartridge. The azimuth is the angle of the stylus in relation to a vertical line going through the point of contact of the stylus with the record surface. Very few (if any) cartridges have a perfectly vertical stylus when they come from the manufacturer. It should be fairly clear that if the stylus is not vertical, it will not be centered in the middle of the groove. And that will create at worse an audibly defective balance, and at best a lack of focus in the sound image that should be corrected in order to give the cartridge the best working situation.
With the Kairos and the Talea™ (1st and 2nd generations), you can modify the azimuth setting while listening to a record, so at least that part of the process is made much easier, and should help you have fun experimenting.
(photo Michael Cole © 2010)
The best way to set the azimuth is by ear (see the note at bottom of this page). Note that if you hear a defective azimuth adjustment as an obvious problem of balance--if the sound is predominantly to the left or the right--, that could be because the azimuth is off (er, check the balance on your preamplifier first, of course!). But there could be many other causes, such as problem with room acoustics, deficient electronic component in one channel, etc. It's best to first ensure that there's nothing unbalanced in the rest of the system before attributing the problem to azimuth. It is however true that a center image can sound slightly off center if the azimuth if not perfectly adjusted.
Here are some tips to help you with this process:
Use a mono recording with relatively sparse material (for example, of a female vocalist). As you adjust the azimuth, you will perceive that the voice has the best “presence” when the adjustment is right on; that indicates that the stylus is perfectly vertical and centered in the groove; if it is even slightly off, the voice will sound somewhat recessed and unfocused. There is a very fine line between being right on, or not quite there yet; usually, a fraction of a degree is all it takes. So you really have to be very subtle when adjusting this parameter. Start with the cartridge vertical. This is just a starting point; remember that with most cartridges, the stylus is not exactly vertical, so just looking at the cartridge won't help much. A perfectly vertical stylus is what we are trying to achieve, and that's not something you can see with the naked eye.
Before you start changing the azimuth, listen to a short excerpt (2-3 minutes) several times. Identify as many elements as you can: the different vowels the singer is singing, the consonants, the mouth noises; then listen to the instruments: try to pay attention to each one individually. Is there perhaps one that seems to be more separated from the others? Don't listen to instruments or voices in the low register, they won't tell you much in this process. Percussion instruments in the middle or high register can be very useful: listen to the attack, then the decay.
Once you think that you've identified one instrument/voice that you "know" well on that recording, modify the azimuth, in one direction or the other. Let's say, you start by going toward the left (armwand rotated counterclockwise); rotate the arm by a very small amount--when you get close to the right spot, the rotation can be a fraction of degree. Listen to what happened. Then move again, in the same direction. Listen again. Is the sound getting more present, or not? Is the instrument getting more 3-D like, perhaps moving to the front a little, perhaps gaining more separation from the others? Or perhaps nothing changed, or it got worse (more recessed, less focused). Modify again, in the same direction. If nothing is improving, you might be going in the wrong direction. Come back to vertical, (on the Talea™ you can follow your changes on the little scale in the azimuth window) and do the same procedure in the other direction (clockwise). At some point, the sound will seem to change for the better. If it isn't, remember that some cartridges are less sensitive than others to azimuth changes. Or perhaps, you're exhausted by now and can't focus anymore. Don't worry, leave it aside for a while, and just enjoy listening to music.
Note that it's not impossible that the best sound is with the cartridge perfectly vertical! Sometimes the stylus is perfectly aligned.
Some possible clues that the azimuth setting is good:
- Source is larger
- In some systems source is closer (with more depth of stage)
- The sound you are focusing on is more separated from the others than before (more 3-D like)
- Sound source seems louder (consequence of previous points)
- More difficult: trueness of timbre. Listen to instrumental timbres (attacks, decay), as well as particularity of vocal timbre (sibillance and other subtle noises at beginning or ending of consonants, etc)
As with any fine adjustment, it takes time and patience to get it right. It's the same thing with tracking force and VTA/SRA adjustments: you can do it by eye, or follow the manufacturer's recommended setting, and hope for the best. Or you can experiment, try other settings just to see what happens, and suddenly discover uncharted territories. Through practice, your ears will get better at hearing the fine differences, and this in turn will take you to new heights of musical enjoyment.
Nobody said playing vinyl was instant gratification...
Just as a performer needs to understand how to take advantage of his fine instrument, anyone who has engaged for a significant period of time with the setup of a sophisticated tonearm knows that it can take a very long time to understand how it reacts to minute variations and how to anticipate its reactions and play with them. The more you play with it, the more you realize what it can do and how to make it sound its best, and the more it gives you back. And when you get it right, you can sit back and enjoy the new level you've just reached in your analog experience!
Note: There have been other methods suggested in the past. A particularly popular one was offered by Victor Khomenko in the late 90s and seems to have been widely accepted since. In our experiments, we've found that, while this method works very well at a given frequency (most people seem to use a 1 KHz tone for this purpose), it is unfortunately not consistent throughout the frequency range found in music. We discovered that after adjusting the azimuth for perfect balance at 1 KHz with this method, voltage readings with a 100 Hz and a 8 KHz tone give widely different results; one channel would be greatly emphasized at the lower frequency, and the other one at the higher frequency. So while the method is theoretically sound, it fails to address the reality of the musical signal, which is far more complex than a single sine tone. So, until a better and more reliable method is established, our ears will do nicely... and they're free...
Additional note: to be fair, it has been suggested that crosstalk is not constant on all cartridges. Some cartridges (a few?) demonstrate excellent consistency across their frequency range, while many don't. For what it's worth...