[watercourse]

My thought is that the pulley distance (from end of hanger) on mine may have been moved, leading to centering issues.

Actually, no movement at all, what I mean is that "centered" when in armrest is not "centered" when playing music. So that's not the case for you?

[watercourse]

Well, reading your post again it is clear this is not a problem you have. Will check when I'm back in town.

[threadkiller]

OP, the ball of any WTL should be in the center of the cup whether the arm be at rest, in the first groove, middle, or last. If yours isn't the pillar probably isn't in the correct position, or it's strung wrong.
Good luck.

[scaleautoart]

^^^^^^^what he said^^^^^^^

It's Simple

[watercourse]

Can you do us a favor then, and measure from the end of the horizontal post to the rubber grommet? This should be helpful for Simplex owners.

For Amadeus owners, those of you that have no centering problems can also do the same for Amadeus tables.

That should at least control one variable.

The other issue about the thread: when you say don't overlap the thread, are you talking about in the grommet? A little further description would be helpful.

[watercourse]

Watercourse, you are wrong about azimuth.
Cartridge body, not cantilever.

Just saw this. Actually, if your cantilever is not skewed, you'd be correct threadkiller.

If you have a skewed cantilever - and in some cases, a high enough compliance cart that the cantilever is not dead-on center when playing - you would not be getting azimuth correct if you rely on the sides of the body. This is based on experience.

So, while in cases where cantilevers and cart bodies are in perfect alignment, aligning to the cart body could be a good way to set azimuth, I say just align to the cantilever, which will always be the correct way to set azimuth. I'm not alone in this method, btw.

[watercourse]

OK, so I'm back now, and have looked at my setup. The fact that others have a consistently centered ball means that it can be achieved. Currently, I have the ball centered when it is midway-ish on a side. This means that it is closer on the right hand side by 1mm to the side of the cup when in the arm rest.

A couple of things after RTFM again:

1. I originally thought that the grommet "trench" was much narrower than I recalled, but it's pretty wide compared to the nylon thread. This means that there is potential for a lot of adjustment within the trench at the time you are hanging the ball, which renders the grommet distance less critical than I imagined (while away from the table).
2. I found that the amount of adjustment of the nylon thread that this trench allows can make the golf ball off by +/- 1mm from center (when using the nylon thread tubes compared to the sides of the cup). IOW, not off by a great deal.
3. The manual says damping cup placement is not critical. I would agree. I'd say the pivot point, i.e. the central vertical axis of the golf ball, is the critical distance we are looking for. This may lead to problems using the cup to gauge where center is, i.e. if the cup's central point is not on the same vertical axis with the golf ball. In other words, your reference may be off.
4. I am asking Mike Pranka whether using S-P distance to set the pivot point would be a good way to ensure that the arm is set up properly.

In the meantime, I've set up the arm from scratch, including rehanging. I've futzed around with moving the grommet to the point where the ball is central regardless of where the arm is - I guess I should have moved the grommet before, but assumed it had not been moved from factory settings - duh. Now the ball is always 5mm from the cup on all sides.

Now for the listening tests and azimuth drift - will report back. Aligned the cart square with the headshell, which was checked to be 19 degrees.

EDIT: In case anyone wants to know, the grommet is 29.75mm from the end of the horizontal rod.

[threadkiller]

As to azimuth alignment, I go by what Firebaugh and Pranka do.
As for the rest, I just put an ice pick thru my eyes so I won't read another forum...
Have fun !

[watercourse]

threadkiller: good thing you don't need to read this thread, it's meant for people that don't have the set up correct. Nor can you read it now anyways with a big hole in your eye I suppose.

Initial impressions: the outer groove distortion is improved...

[scaleautoart]

In the meantime, I've set up the arm from scratch, including rehanging. I've futzed around with moving the grommet to the point where the ball is central regardless of where the arm is - I guess I should have moved the grommet before, but assumed it had not been moved from factory settings - duh. Now the ball is always 5mm from the cup on all sides.

Yep...the grommet sets front to back and swinging the arm left to right. Glad you decided to go back and set it up again

[watercourse]

Well, this bit of reverse-engineering has helped me very much, even though there are some that may not agree. My Shelter likes this alignment better too.

[G E]

Some of the developments so far...

Regarding a jig for easily centering the golf ball.  I realized it would be just as effective to have 3 spacers 120 degrees apart on the diameter of the cup.  They would be easy to install and remove etc, like miniature clothespins, the old fashioned kind with a long slot, not the kind with the spring..  I found some pieces of nylon/vinyl that were once part of a Hunter Ceiling Fan blade balancing kit.  I thought I could cut to my purpose.  As they say, close but no cigar.  Working with close tolerances on small pieces with a vice and hand tools just wasn't accurate enough.  Again, a 3D printer would be just the ticket to fabricate these things.

Anyway, I ended up just eyeballing it and it looks pretty close.  Still experimenting with VTA, silicone damping etc.

BTW, fine VTA adjustments are challenging.  I used small pieces of yellow electricians tape on the deck and on the post, made alignment marks on each so I could return to square one if things got too bulloxed.  An idea I have is to go to the local hardware store and get a large nylon/vinyl bolt and nut.  This could be put under the post for adjusting VTA.  Turning the nut would allow minute adjustments while supporting the post.  One still needs to tighten the set screw at each step, otherwise the post is not perpendicular.

I am using a DIY cork mat that replaces the stock one.  Much livelier sound.  I use the stock mat as a dust cover for the platter.

Lastly, I ordered a 12 V DC linear, regulated power supply and its over voltage protection module for Amadeus.  At 3.4 amp current capacity it is overkill, but I can use it for other projects when not spinning records.  I plan to set it at 11.5 volts and dialing the overvoltage cutout at 12.5 or so.  I thought about a battery power supply for about 10 seconds. 

ge

[watercourse]

Hi GE,

After doing measurements and modeling various alignments and mounting distances (see my other thread for more details), I retract my previous comment about centering the ball in the cup. Based on the modeling outputs, this has less significant effects (good or bad) compared to getting the 19 degree offset angle correct.

FYI, I did plug in the mounting distance for the 10.5" arm for the Amadeus, and found that the distortion curves were the "ideal" curves that I was aiming for in experimenting with my Simplex alignment. It is not achievable with the Simplex, but it is with the Amadeus and other WTA arms of the same effective length. This stands to reason of course, as the Amadeus was the first of the new Firebaugh designs, and all designs following used this model.

Again, these are all numbers, and the proof is in the listening. I don't have an Amadeus, so can't provide any more specific help.

One last thought: If there are issues that seem insurmountable though you have the offset angle correct, and the ball reasonable centered in the cup (and assuming VTA, VTF, damping, and azimuth are all correctly adjusted), you might consider a mismatch or problem with the cartridge itself.