Fast azimuth test...

[Thomas_A]

made a boring azimuth adjustment today...

which meant demonting a remonting using washers. No systematic test here but just three measurements:

No washer; L-R: 24 dB, R-L: 33 dB
One washer (CC tilt); L-R: 30 dB, R-L: 36 dB

Two washers made it worse: L-R 29 dB, R-L: 25 dB

Sweet spot cannot be really optimized but one washer is good enough.

A quick measure of IMD revealed lowered values, but then I also have remount the cart = possible change of alignment.

But I need anyway to redo the antiskate, so more measurements are coming...

T

[1200y3]

MM carts have different charactersitics than MCs. The poles of a cartridge have to be parallel with the record surface, because the stylus will only deflect (pick up) in the direction of the grooves. We have to balance crosstalk and channel balance. The balance control can look after channel balance. But then what does the record see as parallel?

The best alignments are as close to the cartridge as possible, by using the washer technique. I bend the stylus to adjust VTA after everything is completely level.

The MC stylus has to be prfectly in line.

The tonearm and wires add most of the crosstalk.

[Thomas_A]

I think after some listening, that azimuth is a quite important factor in setup. Sound is a bit cleaner and more open.

Due to its difficulty to check, azimuth is usually overlooked - test records are needed.

I whish I had a finer tool for it (need another arm...), perhaps I could go down to -35 dB both channels.

And I think crosstalk is the one to go for. Channel balance with the V15Vx/JICO is already within 0.1 to 0.7 dB, depending on signal (much better than the original stylus - i.e. very high quality stylus geometry with JICO). Channel balance change very little with azimuth, but crosstalk is very much changed with small alterarations.

T

[Luckydog]

[Thomas_A]

Yes, agree. Many tonearms does not allow for fine-adjustment of azimuth. Strange, since one could improve things by this.

Since we are dealing with stereo signals, the cross-talk may be regarded as distortion, although signal-related.

T

[Thomas_A]

There are several things that I do not understand here, and I hope there could be some discussion regarding measurements and setup.

I do see a decreased overall IMD after changing azimuth, down under -40 dB for primary sidebands. There is a bit more asymmetry though and there is visible secondary sidebands (which were not before).

But of course I probably also changed LTA as well, it is impossible to have exactly the same settings.

Does anyone know what happens to IMD vs. azimuth? As with SRA and VTA, changing azimuth change two things simultaneosly: generator and stylus fit in groove, which are separated.

Is there any azimuth papers out there with IMD and crosstalk measurements?

T

[pivot]

[lanny]

Ease of azimuth adjustment is one of the advantages of a unipivot with a dropped counterweight.
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[1200y3]

Most Styli are angled absolutely perfect, but even the V15 MR came with a tool to bend the stylus (a newbie shouldn't be using a V15 MR, either should I). And it is extremely risky to bend styli, almost all of them. There is no better way to adjust a stylus than at the stylus, so to any newbies that wonder why they hear no difference when they do all those fancy arm adjustments, adjusting the arm only affects the arm. But you can learn with $20 generic replacements. The cheaper styli are the ones where the differences in adjustments are learned.

Any newbie better realize that doing azimuth adjustments and crosstalk checks on a good cartridge, or any is extremely risky. But the arm should be level and the stylus tip should match.

Shim the cartridge to set VTA and azimuth then, but keep the cartridge azimuth level with respect to the platter to be safest. For VTA set the stylus tip sraight up and down with a flat top (it it hs a flat top) regardless of how level you can get the arm. It may only need a better platter mat, but VTA is the most impotrant for mechanical pickup. The tip should not teeter.

Sometimes the stylus tracks better when it is slightly angled to track the radius (another offset angle this time vertically and laterally), so don't be surprised if doesn't sound perfect when it looks right. (Which is really all I should have said.)

[Letitroll98]

[pivot]

[1200y3]

I did not suggest to bend the stylus, I only stated that I do (and it is only with cheap styli). I read about the styli cradle in a magazine (Stereophile or HI-FI world) and it works both to measure and adjust. The alignment guage instructions for the Duo-Point and azimuth guages supplied with the cartridges are separate anyhow. I may add them to the library. Who knows how many other adjustment instructions they had?

I stated to keep the cartridge level (as per instructions), use the shims, and experimenting with compelx alignments is risky. The cartridge and styli alignments give better results than adjusting the arm, as long as the arm is level and square.

With all due respect (for safety issues) I do not want to pack up somebody else's forum topic. I should also point out that only certain styli are practical for adjusting.

Glutten for punishment? But I've got about six cheap replacement styli, and I don't have $500. Sure, trying to build needles on a kitchen table can be infuriating, but also rewarding. Furthermore I like de-coupled styli, (the ones they can't sell because they fall apart), and they are adjustable. They make the M97 sound dull. A/Ts are less coupled because they don't have a suspension wire. (But don't try adjusting the stylus tip.) My sound system isn't going down due to a broken needle.

If you are going to purchase a Koetsu without knowing how to build a decent stylus from scratch, I would pray you could afford to. There are many on the second hand market. Regarding the Coralstone, it is like I've been stating all along, the cartridge dressing has the greatest influnce on the sound. Wrap an M97 in coral and it will sound better.

[Thomas_A]

Why not use stylii that already are under good QC? I know that all stylii are different and perfect alignment is not possible. Bending means stress to structures, and I would not go outside spec. Already playing > +12 dB may be a bit stress to the stylus and suspension and specifically the torture track. I have used it, but nowadays I am hesitant to use it as a "test" for good tracking. It may force stylus and suspension far above spec and cause some damage.

Nevertheless I believe in measurements as good guide for cartridge setup. So again crosstalk is a good measure of coil symmetry to groove, but then what if the coils are perfect but the stylu is not?

I would suggest that azimuth is the most important with respect to "small adjustments". LTA could be good within ±1 degree or so (since it can never be perfect over a record) but azimuth may be critical within fractions of a degree.

So besides crosstalk, what would IMD signals tell us about azimuth?

[crofk]

1200y3 wrote:

I bend the stylus to adjust VTA after everything is completely level.

1200y3 wrote:

I did not suggest to bend the stylus,

WTF?????

This guy ever read what he writes??
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[pivot]