Turntable leveling

Pardon the possible obtuseness of the question, but - in the opinion of forum readers - how important to sound quality, LP and stylus wear is having my turntable precisely level? Try as I might, I can't get it <2 degrees from absolutely horizontal measuring with the Levlx iOS app though it looks good with a bubble gauge. I've looked online and I can't find a consensus opinion on this matter though I know the more level the better.
Thanks in advance,Keith
If it looks good with a 'good' spirit level then you are fine.
Quality off spirit levels varies a lot. But i'm not talking $1000 calibrated levels used by CNC mechanics. Just not a cheap plastic one...
I would trust a decent spirit level far more than any mobile phone app.  "Decent" being any spirit level bought in a hardware shop or such, rather than a $0.95 one bought on eBay and shipped from China.
Same thing goes for CD players, but the top of CD players may or may not be the same level as the spinning disc. 
I have a pretty decent setup which satisfies my commercial grade bubble level. One day I was adjusting something -the thing is HEAVY- and the front right cone fell over. I set the table back on the fallen cone which caused the table to tilt to one side by about 1/4 inch. I played a few LPs and didn't notice anything particularly out of kilter. Which is nuts... because I can detect 0.25mm VTA! It's all relative.
Thanks, everybody! My blind trust in a free "high tech" phone app may be misplaced. I'll trust the bubble level even though it's a cheap one. Maybe I can borrow a better quality one just to check.
... because I can detect 0.25mm VTA
Not likely, especially because common LPs aren't flat within .25mm. If you're convinced you can hear a deviation that slight, it suggests that your stylus may be chipped or damaged. That could account for your claim.
I think that with static balance tonearms it is a primary concern, but with dynamic balance arms it is of little consequence regarding cartridge wear and tonearm sound quality. 

The main turntable bearing having the weight evenly distributed, both from the perspective of wear and of sound quality, is quite important. 
I use an "analog" bubble level, and that seems fine.  So my answer to your question is don't fret over it.  On the difference between your phone app and the ordinary bubble level, I'll go with the latter.  I have an "audiophile" bubble level, meaning you center an air bubble in a circle, unlike with a carpenter's level, where you need to level it in two directions. If the bubble is just barely touching the inside of the inscribed centering circle, that's acceptable to me.  If the bubble edge lies outside that circle, I adjust to correct.
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something to also consider: is the tone arm level to your plinth. good idea to make sure both are true to each other so when you level the whole table everything is true to each other. Not such an issue with tables that have an arm mounted by the manufacturer, but if you've added another arm defiantly check that it is leveled to your plinth.

 I ran into this issue when assembling my Garrard, the Jelco arm (750L) as good as they are have terrible VTA Adjustment that can and does change the arm level to plinth when tightening the VTA Set screw. 

ahh...the complexities of vinyl! In my case I have a Moerch UP-4 arm on a VPI HW-19 turntable. Thoughts on absolute level or not worth the exacting effort for this rig? I have about 1000 vinyl records, mostly vintage (Shaded Dogs and others of that ilk), but each individual LP doesn't get played all that often.

Thanks in advance,Keith
@cleeds Slight exaggeration for effect. I have dialed in tiny adjustments though. I have a 1962 Julie Andrews record which responds to the tiniest change which snaps the vocal into pinpoint focus.
Cross check level at Home Depot $3.96
VPI cross check level at Music Direct $10.00

The old level-level saga...easily determined by placing the level on a surface, noting the reading, rotating the level 180 degrees and placing it on the exact same spot and again noting the reading. If the readings are the same...the level is level.
+1 with Glen; level the platter surface and the tonearm mount board or achieve the same degree and direction of error for both. Forgot to bring that up.
My turntable sits on a 150 lb circular granite slab glued to a gimballed gearing from which hangs a 250 pound pendulum. It is accurate to 1/1000 of a degree. Just kidding. A spirit level is all you will ever need.  
I had a small circular level ( bubble inside circle) that came with my Clearaudio turntable when I bought it. So I set up with that.
Then checked with a small joiners level  (4 inch) and then with a larger ( 2 foot) builders level.
They all showed the same. I am thinking that fraction off would not be a problem audibly. As to wear, I do not know.

Haha! “An ‘analog’ bubble level”
I laughed aloud at that. 
Not sure why it was funny to me, because it’s pretty much true.
If a little round bubble level doesn't give you perfect leveling, you're living too close to the North Pole.
@glennewdick We may have spoken about this before but there is an after-market unit called Easy VTA for Jelco arms.
A good while back I picked up three packs of ten cheapo bubble levels from eBay, just out of curiosity. From China of course. Ten tiny ones (7mm diameter), ten slightly larger (12mm) and ten "large" ones (32mm), all of the circular disc type, the large ones with several lines purporting to show degrees.

I tested them all against a calibrated spirit level I borrowed from a friend and the results were not great. Of the 7mm ones I kept 3, of the 12mm ones I kept 4 and of the 32mm ones I also kept 3. The remainder all had serious deviations and ended up in the garbage.

Just a FYI in case anyone has bought, or are considering buying the same. By all means do so, but don’t take their accuracy for granted and don’t rely on them before you’ve checked them against a verified spirit level.
Thanks everyone for the comments!
You can by a record clamp with a bubble square over the thing that you put the record on . Easy to make it perfect, had  one for at least a decade .
Starrett 98-12 precision bubble level, Amazon $219. Tell ‘em Willie Boy sent ya! 
$219 for a bubble level seems a bit pricey for a non-pro but I suppose I'd want a builder to be using the best possible for the job.
This particular weight isn’t very heavy, but the bubble level is pretty handy and it's very affordable as far as weights, clamps, etc. go - https://echohifi.com/details/12083/Echo-Audio_Record-Stabilizer


Thanks for the info! Echo HiFi is only a few miles from my house!
Keith, lucky you! I not sure if their new place is open yet. 
I’ve used a bubble for more than forty years.  Never had a problem that I know of.

All the best.

I leave a small bubble level on the tt deck, always verifying level.

Bubble Levels can be defective. I have several various plastic ones, they all agree with each other (and they agree with my more professional levels I double check with).

I just bought a nicer stainless steel one with blue fluid to look good with McIntosh blue meters for an amplifier stand I will be selling on eBay. The new one is off a few degrees, what a shame, perhaps a tiny imperfection inside that prevents the bubble from centering. My quest for blue fluid is not done, the first one said blue, showed blue, came green. 
FWIW, the better quality tools, the better the project

Just make sure that when the platter is level your tonearm mounting plate is level.
It is imperative to get the tt level PRIOR to:

1. arm height adjustment.

a. sufficient clearance when lifted, enough space when lifted to brush/liquid clean stylus and/or clean dust off anti-static brush if used. Back to front of course. Once set, I do not remove my headshell from the arm to clean it, it stays 'perfect' and gets very carefully cleaned in place.

b. arm floating parallel at zero tracking weight, zero anti-skating.

c. height for proper vertical tracking angle into the groove while lowered/playing.

2. cartidge alignments (forward/back and left/right in the headshell to achieve best parallel alignment at the 2 points throughout the arc on the alignment gauge. Critically tedious, and things move as you tighten, double check, do it again, again. Check after a few months, proves you got it tight enough.

3. view from front: perfectly straight down into the groove (tiny shims in the headshell may be required, they are the worst, but, nirvana awaits). If you add shims, you gotta set the 2 points of alignment again!

I use a thin mirror on the platter. Lower the stylus, nose down, eyeball straight at it: any slight angle will be more easily seen.

4. tracking weight (zero anti-skating for this).  Shure anti-static brush: brush up when setting desired tracking force. Add 1/2 gram when calibrating, to compensate for the brush's upward force in use, i.e. 1.75 without brush = 1.25 with brush in use. Then, set anti-skating for 1.25 to match the effective tracking force of 1.25   

5. anti-skating equal to tracking weight. This is VERY important, and, assuming prior adjustments are correct, needs to be refined by ear. Test records, your most familiar recordings. Proper balance left/right separation, center image is all critical to this, stylus 'free floating' in the center of the groove, ready to properly respond to all vertical/left/right input.

Note: I use my McIntosh 'mode' switch, go from Stereo to Stereo Reverse, you know for sure if anything changes. Mono to left, mono to right, .... it is one of my favorite McIntosh features.
My question is after doing all that will I still have time and energy to play and listen? I got all tuckered out just reading the list. 

This is something you have to do every time, right? I mean, level depends on gravity, which with the moon....
I agree: there's so much time, effort and expertise required for managing a vinyl playback system that sometimes it hardly seems worthwhile. Nonetheless, having a large vinyl collection (and occasionally giving in to the urge to buy a special LP), I continue to use and enjoy the medium despite the trouble and the cost.

I've acquired a Swedish Inogon Combination Level and Angle Reader which is reputed to be highly accurate. Using that, I confirmed my turntable is about 1 degree off from perfect horizontal and (interestingly) the reading perfectly matches the free iPhone leveling app's reading! In my humble system, I doubt that the small deviation from absolute level will be audible...I hope!
Put it this way. If you bring it to level by putting something like a piece of sorbothane under one corner, that piece of material (whatever it is) will have a greater impact on the sound than the one degree.

My table has been mounted on the same massive (close to 600 lbs) stand for well over a decade now. Level at one time it must have settled because when checked recently it was a bit off. Not that I noticed. Anyway, it left me with a couple options for adjusting it back level. Main thing I noticed was even when using shims under the platform- not even the turntable itself but the platform under the table- the material used made a difference. Never did hear any difference being level. But what I did to get it level, that DID make a difference.

Those are good points, indeed. I'll let the obsession go!
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