VTA setting up.....how do I find level?

I've read advice to "raise the rear of the tonearm .03 inches from level" for best performance of my Lyra Helikon cartridge.

OK, how do you find level? If I place a bubble level on the tonearm it stresses the stylus with the extra weight! (damage potential!?) and bends the arm down, so it's not in the normal playing position.

Then, the numbered barrel on the JMW12.5 arm indicates what? (numbered 0 through 99)

Could someone address this particular step of the setup please?
Jbatlanta, Ultimately you need to do the fine tuning of both VTA and tracking force by ear to get it right. The measurements and the guages (whether for vertical tracking angle or vertical tracking force), simply get you directionally correct. They are never absolutes.

Fortunately, adjusting by ear (by listening) is not as difficult as one might imagine. The trick is to always follow an ITERATIVE PROCESS of adjusting in one direction until you over-correct, then reversing direction until you re-gain your objective. Works for adjusting VTA, and works for adjusting tracking force.

For an excellent description of the process, and for what to listen for, read Lloyd Walker's description for "Fine Tuning Your Turntable" at his web site:

It's not as difficult as one might initially imagine.

To try to answer your specific question, though: In this case, the guidance being given is to have the cartridge canted up slightly to the rear relative to having the (bottom/top of the) cartidge body parallel to the surface of the record. But, whether the .03" refers to the change in height of the arm at the pivot point, or the difference in height from the front of the cartridge body to the rear of the cartridge body, I couldn't begin to say.

I really recommend you go to Audio Asylum and on the home page click on FAQ. Scroll down until you see the section on turntable set up. If you read all the posts and especially Jon Risch's "VTA and forget it" you'll be an expert.
Thank You for these resources.

Lots and lots of reading to do.

As a start, and if your arm is not tapered, the simplest way to get to "level" is to take a lined index card and place it behind the arm wand as it lays on the record surface. Line up the card's lines with either the top or bottom of the arm wand. That's a starting point, and no it's not precise - just by eye. But it is far better to have that reference point than trying to eyeball it without one. I couldn't believe how far off I was without it.

Good advice from all three posters above. The Jon Risch article referenced by Lugnut (I think the title is actually, "VTA once and for all!") is the best theoretical place to start

Risch recommends a lined guide card just as Bob did.

The approach explained by Rushton is ultimately best. Both VTA and VTF must finally be set by ear, listening to familiar recordings.
You want to level the bottom of the cartridge body with the vinyl by eye as a initial set-up. The armtube is not the place to look first - especially tapered arms.
Actually, I have to credit Dougdeacon for pointing me in the direction of the Jon Risch post at AA a month or so ago. I was going to post the recipe card suggestion but since so many of the cartridge bodies are not a true rectangle I decided not to. When using the card make sure that it's up against the cartridge body or very parallel to it. Also, make sure the card is not influenced by the outer hump on the record. Shorten the card to avoid the outer edge.
Hi Patrick. Good tip about avoiding the raised rim. LP labels are often raised also, so they too must be avoided. Oy!

Of course Risch's use for a lined card is not to square the cartridge body. We don't play music with that so why align it? Risch wants us to adjust the contact line of the stylus itself - 2 degrees forward of vertical. Having a visual reference for such a tiny line must be helpful, as Bob found.

Of course if you insist on using an armboard thats 1/2" too tall you won't be able to align anything! <;-/

The armboard may be right for all I know. Both the arm and the board are on their way to Chris. I'll let you all know what the culprit item is. I'd just like to get this done right and hear it in it's glory before it leaves my house. Besides, I don't find it fun at all to handle these pieces more than the minimum if you know what I mean. Regarding the 901, the stylus is an irregular shape so visualizing a vertical line through it is impossible for me. I'll have to do it the way I've done it for the last 35 years; using my ears. Finding level is a very good place to start. I thank you again for pointing me to Jon's post at AA.
For the longest time I thought the 901 stylus shape was peculiar too. But in fact it simply has a tendency to rapidly build up crud where the stylus meets the underside of the cantilever. Properly cleaned you can see that it's shaped like a sharp V when viewed from the side. The contact lines pretty nearly bisect the V.

It does need a good set of eyes to see this. A wide angle lens for a 35mm camera makes an excellent magnifier, I use my partner's 28mm Canon lens and it works great. Take the lens off and look through the outer end, with the film end of the lens aimed at the stylus.

Of course setting by ear is what you must do in the end anyway, so ignore all the above!