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
Azimuth adjustment is not about achieving balanced output between channels, nor is it correct to alter preamp channel balance before adjusting it. Preamp channel balance should be set wherever you normally listen to achieve sonic balance in your listening room.

Unless I misunderstand your post, you may be starting from a false assumption.

Dear Dr. Cilantro,
What Doug said. Azimuth is about crosstalk between channels, the amount of the signal in the L channel that appears in the R channel, and vice-versa. It is not about channel balance. In fact, even at extremes of azimuth, the voltage output per channel will change very very little, by about 1db in my actual experiment.
Your friend, Dr. Habanero
If one had a voltmeter sensitive enough to measure voltage directly off the cartridge pins or tonearm wires then there would be no need to equalize voltage output across channels prior to measuring crosstalk.

I thought the reason for achieving (roughly) equal voltage output across channels by adjusting channel balance was to address voltage imbalances arising downstream from the pre-amp as known at the point where the voltage measurement is taken, eg at the amps output terminals.

Doctorcilantro didn't say that adjusting azimuth was about achieving balanced output channels. I understood his statement to say he would adjust channel balance prior to adjusting azimuth.

Of course this may all be moot if you believe one cannot measure channel crosstalk at a given frequency and adjust it using instrumentation.

Unless my understanding is off base (quite possible, thank you for your patience) and one can indeed not measure crosstalk and changes made to it by azimuth adjustment, then I'm inclined to believe that the 'ears vs instruments' debate is a false dichotomy and neither is an 'advance' over the other. I heard no one claim that use of an instrument assures better results than careful listening. Setup procedures are not a zero-sum game and ears and instruments are not mutually exclusive techniques.

Use your eyes too. Regardless of how 'good' you think it sounds, if your stylus (or even your cartridge) visibly is canted at an angle, something may be askew with internal motor position or elsewhere in your system. Attaining proper azimuth is also about reducing potential groove damage.

Heaven forfend our cochleae are not gain level neutral and constant from day to day. Regardless of one's golden capacity, I find instruments properly used tend to aid rather than hinder. They can also let you know if results achieved solely by listening are aligned or not with what measurement says. Once you've learned, maybe you no longer need them, but a second opinion rarely hurts.
Yours truly, Professor Pesto
I was wondering if anyone could give a succinct (if possible) tutorial on how to use an analog multimeter to adjust azimuth for someone with no engineering background (in other words, azimuth for dummies as it were). In the alternative, perhaps someone could point me to such a resource. I have Fremer's tt set-up DVD but it's useless in this regard. It would be greatly appreciated.
I think this is what it boils down to. Please anyone correct me if I am off base:
(1) You need a test LP that has a band where signal of a known frequency is recorded for one channel only. Lets say it's the R channel. Play the band and measure V in the R channel. Now play that same band and measure V in the L channel. That V represents crosstalk of R channel information into the L channel. The difference in V can be converted to db. Formulae are on the internet.
(2) Do the exact same thing, only this time play another band on your test LP that drives only the L channel at the same frequency,. Measure V in the L channel and V in the R channel and again calculate the difference in db.
(3) Adjust azimuth so that you get the largest possible absolute values of db for both sides. It's always a compromise.