Alignment Snafu? Or?

Thank You Narrod, Another person has advised me exactly as you have, to perhaps trying Stevenson Geometry.

While my rig is sounding pretty darn good, I think all can sympathise, trying to squeeze every last bit of performance from my vinyl rig. My ZYX Airy 3X is still very young in age, certainly doesn't have sufficient break-in time on it yet, but sounds better, and better each time I play it.

I have been able to achieve dead on alignment with the TB protractor, and yet wonder, with these sight line protractors, and even though I've noted a 1mm error on mounting distance, is alignment still correct? I've used the outer grid to align, have aligned the stylus, and cantilever, not the body, and haven't concerned myself too much with the inner grid on the protractor.

I do get somewhat confused with protractor geometry (wasn"t the sharpest crayon in the box in match class) but gather that regardless of mounting distance, sighting with the sight line protractor "should" net me correct alignment?

If I am incorrect about this, I am hopeing somebody will correct my wrong assumptions. Thank you, Mark

Mark, I think that from your description of the issue you may just have to live with a small amount of error in the setup. In reality, we all do. The only thing we may be fortunate enough to do is limit that error more in one setup than some other setups. But it has been published in several places that an error of less than .5 mm is almost a necessity to get the most from a particular arm/cartridge. This doesn't mean that you won't still enjoy what you hear. Perhaps this is something to keep in mind if you ever go looking for a table upgrade.

Hi Mark,

Dan alludes to the active thread here:
http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1210959908&read&3&4& where you'll find several informative links.

Read this stuff and then read it again. Know that using a sight line introduces more error than it attempts to correct. I'm not arguing that you can't get "lucky" using a sight line, but we want to eliminate luck from the equation and introduce repeatability.

May I humbly comment that you don't know how good your setup can sound, and won't know until you set it up with an arc-style protractor which agrees with the pivot to spindle distance of your rig?

Know that you want to take your best shot at having a protractor to match your current pivot to spindle distance - as long as you have enough room in your headshell slots to accommodate corresponding effective length and offset angle changes.

So, if your actual p-s is 210, that's fine, as is 212. It's more important to know the distance as precisely as you can measure it. This assumes two things: (1) that you have headshell slots long enough to accommodate the new tonearm parameters, and (2) that if you mount the arm on another turntable that you replicate your current pivot to spindle distance.

Remember, the only down side of an arc style protractor is the effort you need to put into getting the pivot to spindle distance to agree with the protractor you've specified. The up side is huge however and worth the effort.

Unless you're using something like the trammel portion of a Feikert protractor, you will unlikely be able to measure your pivot to spindle distance to within .5mm.

So, try the following before you do anything else: loosen your tonearm mounting screws to see how much play you have - the ability to make fine adjustments to your pivot to spindle distance. You will likely find that you can get +/- at least .5 mm and perhaps more.

IIRC, your AQ arm mounts like a Linn, with three holes that fix a base plate in place. Know that you can enlarge these 3 holes (as well as the arm stub hole if necessary) slightly to get further fine adjustment of your pivot to spindle distance. Just remember to measure twice, and drill once.

No matter how you specify your protractor, you'll want to know what you're up against from a p-s distance perspective anyway, so you might as well know now rather than later.

Be prepared for a revelation when you get everything right.

Cheers,
Thom @ Galibier

A quick follow-up on the Feickert protractor ...

In my above comments, I was endorsing it as a reliable (albeit expensive) means of measuring pivot to spindle distance and nothing more.

I have not played with this protractor, but people whom I trust tell me that it yields quite a different alignment from those achieved by both the Wally and Mintlp protractors (Baerwaald).

Cheers,
Thom @ Galibier

Just wanted to follow up here, what my findings were, and I hope my post isn't too long, or bores anyone.

Ken Willis very kindly forwarded me some Arc Protractors to try, both Baerwald, and Stevenson Geometry at 211mm, and 212mm.

Clearly determining that my AQ Arm-Spindle Distance was indeed 212mm, I tried the 212mm Baerwald, and had found that my previous alignment with the Turntable Basics Mirror Protractor was right on the money as far as Cartridge Overhand was concerned, but did quickly notice a very small error-discrepancy with Cartridge Zenith Angle, which was off slightly.

It appears that I have no problems attaining alignment at 212mm with Baerwald, the Stylus is dead on in the little reference circle.

And I know the reason why this was, read on.

When I first installed my ZYX Airy 3X, and aligned with the TB Tractor, I didn't really snug the Cartridge Screws that tightly. I knew previously from all the good reads from you smart folks here, that one isnt supposed to lay on the Screw Torque with Gorilla-like pressure, and being that the Finger Lift for the Arm is a seperate, individual piece at the top of the Headshell, in which the Cartridge Screws actually pass through, and then on to the Cartridge, by moving the Arm from its rest everything you play an LP, the Cartridge must've have ever so slightly twisted sideways on the Headshell.

Another reason, I was perhaps afraid to over-tighten the ZYX Cartridge with its Acrylic Body, and had feared possible damage to the body by snugging the Screws too much.

So, I did succeed in snugging the screws a bit better, and all seems well, that my alignment looks to now be nuts on.

Of course, this was a print out, and only a paper protractor, and I'd like to comment about my findings with Protractors. The Turntable Basics Protractor is a great protractor, especially for the money, and I wholeheartedly thank Doug Deacon for suggesting this purchase. But what I do note with a Mirror Protractor, is difficulty in getting all lined up properly, due to difficulty in seeing everything.

As many of you have perhaps also found out, shining a light on a Mirror doesn't really light it up, and aid seeing the reference grid, and exact Null Points. I've tried back, front, side, and rear lighting with many different types of lights, and it seemed higher intensity did not aid the process, and some odd angle lighting seemed to proove best. With a white background though, the contrast seemed much better, and I could more quickly see any errors.

The TB Protractor is propbably not in any way inferior, just a bit harder to use because of this.

Since Ken Willis can make an Arc Protractor with geometries for up to four different Arms-Tables, I'm going to order a custom protractor ASAP, as I have another Table, a Denon with Grace Arm, and would like setting this Table up accurately as well.

It appears Ken is making some very nice protractors, as I have heard so far nothing but praise about what he's making. I understand Ken is a member here, but I cannot recall ever seeing him post here? I know he frequents Audio Asylum.

Perhaps when I get his "official" protractor, I'll comment again in a seperate thread, and perhaps even write a review as well.

Thank you all again folks very much, your help, and advice is deeply appreciated. Also again, many thanks to you Ken for your time, and help! Mark