Azimuth primarily affects two things: L/R channel crosstalk and L/R relative phase. Trying to figure out either of those things visually is not very reliable, as the actual position of the cantilever relative to the cartridge internals is not visible to you.
We use software to measure crosstalk and phase, with the priority on phase as the optimal point for phase is usually close but not necessarily at the exact same point that is optimal for crosstalk, and in my experience small deviations in timing are much more noticeable than the small amount of additional crosstalk you accept in exchange.
Rather than a new turntable or new tonearm, you could also consider a cartridge that has a ridge along the top. This lets you adjust azimuth a little bit by alternately loosening and tightening the screws.
Do you have the silver or the black PL600? On the black one, there is really no way to adjust the azimuth except to make micro adjustments by loosing that little screw at the top of the head shell adjusting the headshell one way or the other, and then tighten the screw again.
However, you mentioned shims in your OP, which really don't have anything to do with azimuth, but more with VTA. Also, have you tried the pioneer experts forum?
What am I missing with this problem?
It has bothered me enough mentally to consider a new table but I’m thinking I’ll need to invest at least $3K or more to achieve an improvement.
Save your money. Relax. Azimuth is not all that.
First, nothing is all that- unless you can hear it. Is your stereo image all fubar? No? Of course not. Or you’d be complaining about that, and not this imaginary azimuth problem.
Go on YT or Soundsmith and watch Peter Ledermann talk about azimuth. It’s not that it’s not important. The problem is it is far from the only thing you are changing when you adjust what you think is azimuth.
The real azimuth adjustment that matters is like nekoaudio says way up inside the cartridge body where you cannot see. The alignment is between the coils and magnets, which we cannot see, with the surface of the record. When we align azimuth by sight we are relying on these inner parts being properly aligned with what we see on the outside.
But twisting the cartridge body to adjust azimuth affects more than this. It also twists the stylus. So if azimuth is off you have the choice- do you want the stylus perfectly aligned? Or the cartridge body? Or the stuff on the inside that you cannot see?
The only real means of doing this then is by ear. Listening is really the only way to know what if anything is better or worse when adjusting azimuth. There are instruments you can use. I have used them. They are in my experience useless. That is to say, there was no real difference before and after adjusting.
Compare to VTA, which is huge. Compare to VTF which does make a difference you can hear. Azimuth is so far down the list, to throw away a perfectly good rig just to gain azimuth adjustability, well if you do I think it will wind up being one of your more expensive learning experiences.
What makes you say your azimuth is "slightly off"? Is the headshell not parallel to the platter surface, when viewed from head on?
Simao, Shims could be used on one side of the top of the cartridge, as a wedge between cartridge body and headshell undersurface, to correct for azimuth. Perhaps that is the intent.
The thing about having azimuth adjustable via the tonearm is that it also affords the user the opportunity to get it wrong. As MC suggests, very often adjusting the cartridge body at an angle to the LP surface, in order to optimize the electrical readouts of channel crosstalk and phase, will also sit your stylus tip at a subotimal angle to the groove walls as regards its physical contact patches. This is "not good", because it leads to uneven stylus wear and distortions that may be more noticeable than suboptimal crosstalk or phase anomalies. I do own 2-3 tonearms that permit easy azimuth adjustment, but in recent years, I have settled on the paramount importance of having the stylus sit "square" to the groove walls, over all else.
But if your headshell is fixed at an angle other than parallel to the LP surface when viewed from the front, I would suggest doing something simple to fix that and then stop worrying.
Also, if you look on Soundsmith and study well you will see Peter Ledermann came up with an ingenious solution that enables all his cartridges to have azimuth adjustment regardless of what arm they are used on. When you see how it works you will realize you can do the exact same thing yourself. Simply place a round toothpick along the center line between the cartridge and the head shell. Then by adjusting the screws you will be able to rock the cartridge one way or the other and wala, azimuth adjustment!
Looking at the headshell head on there is a slight visible tilt, maybe 3 - 5 degrees visually. I do not have measurement devices to check cross talk, etc.
The sound is good to very good, with good imaging. My particular listening situation is a little compromised by the use of the listening space also as a family/great room. My wife tolerates it, kinda.
3 to 5 degrees is not trivial. Take a look at MC's reference to Peter Lederman's tooth pick trick, and maybe try it. Perhaps you will enjoy your sound even more, by a tiny bit.
Correct azimuth allows you to have a soundstage that, for many recordings, extends well beyond the speakers and well behind them. Since I listen to classical music, I think the rewards of a proper azimuth are large and rewarding. YMMV.
The adjustment is very easy with my arm. I find that with the proper records, I can adjust it by ear. Some people use expensive devices to do so. I have read about them and I would find them a pain, and expensive pain at that.
Though others may differ, playing a mono record with one channel out of phase will get you very close, perhaps close enough.
Playing a mono LP with one channel out of phase will tell you more about channel balance, as it pertains to the electronics downstream from the cartridge, than about azimuth, would it not? At least that is my first reaction; I am thinking about it some more. How do you define "correct azimuth", with respect to the placement of the stylus in the groove of a stereo LP or with respect to crosstalk (and phase, if you want)? What do you hear when you do it? Seems like with a mono LP, you have a mono signal with uniform phase off the LP. The exact same signal is then fed to two channels in a stereo system. Then when you reverse the phase of one channel, you would still have signal out of that speaker and also you would have signal out of the other speaker. To some degree the two would acoustically cancel, but not nearly perfectly, because phase is affected by room reflections. Seems like you would lose SPLs and the tonal balance would be messed up. I'm just curious.
True, too much work for little return. Other parameters as overhung, vta/sra, tracking force, even antiskating are far more critical.
a mono LP with one channel out of phase will tell you more about
channel balance, as it pertains to the electronics downstream from the
cartridge, than about azimuth, would it not?No, not at all. You can easily measure the channel balance of each component downstream from the phono cartridge, then factor that into the result of measuring the cartridge channel balance through the same electronics.
How do you define "correct
azimuth", with respect to the placement of the stylus in the groove of a
stereo LP ...In this instance, azimuth is correct when the stylus is located with perfect symmetry in the groove. As others have noted, there can be slight misalignment of the cartridge coils, so aligning the stylus alone may not produce optimum result.
Seems like with a mono LP ... The exact same signal is then fed
to two channels in a stereo system. Then when you reverse the phase of
one channel, you would still have signal out of that speaker ... To some degree the two
would acoustically cancel, but not nearly perfectly, because phase is
affected by room reflections ...You're correct, of course - that's why you don't use speakers when using a mono LP and out-of-phase channel to check azimuth. Use a meter instead.
EVERYTHING makes a difference the better the system it's usually easier to hear these differences.
The more advanced the stylus shape is, the deeper it goes into the grooves, the more important Azimuth becomes.
Not just for sound, but to avoid groove damage, AND get the advantages of greater surface contact area, longer stylus life.
I start with a mirror the same thickness as an LP. Carefully drop the stylus onto the mirror.
View from the front, the mirror will oppositely reflect, thus reveal any deviation from straight. Now what? I had to put tiny shims on one side for an arm with no adjustment, a total pain in the arse, and you want the headshell tight to the headshell, so tedious, but worth it.
Also a transparent block with grid of lines is helpfulhttps://www.amazon.com/gp/product/B07794JXYZ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
this transparent protractor for side view for VTA, Stylus Rake Angle is helpfulhttps://www.amazon.com/gp/product/B01HF9PEA4/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
Dover, I could take issue with some elements of your response to my post, Like for example that when you use a meter, you are measuring the sum of any difference in channel balance plus voltage differences due to crosstalk, but it is not important. When I asked how do you measure azimuth, that question was directed to the OP. I was interested to learn why he felt his cartridge was running with incorrect azimuth. I know how I measure azimuth, and I know that you know how you measure azimuth. I was addressing the OP.The point is, as your response also indicates, there are two different criteria for “correct azimuth”. One is the physical model that you describe, and the other is according to the electrical model, where you measure crosstalk in db or voltage . Those two methods can give very different results. For reasons that I and you and some others have already suggested.