AudioCircle
Audio/Video Gear and Systems => The Vinyl Circle => Topic started by: Quiet Earth on 12 Sep 2014, 07:39 pm
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I suppose this is a beginner's question for most readers here, but I never really understood why my turntable needs to be perfectly level. I think I understand why you should set your turntable up on a level surface and aim to get it close to being level. But let's say that you are using a circular style bubble level on your platter or plinth and you stop leveling it somewhere that looks close enough, but not perfectly level. Is this a sloppy set up?
Let's try this question another other way. If I continue leveling my turntable until it looks perfectly level, what sort of improvements should I hear compared to having it just close to being level?
Sorry if this is too basic of a question, but I am not very mechanically inclined nor too sure about the nature of these things.
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Much of it works with gravity. I'd think the implications are pretty obvious.
The difference between grossly off level and perfectly level is substantial. The difference with everything in-between is hard to quantify.
neo
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Hi QE,
Here's an answer to this I provided on another thread. "A few turntable types (say most notably air bearing or other free floating linear tonearms) need to be leveled very well. Most of those with fairly ordinary pivoted arms actually do not. The degree of offset of lateral forces that might arise from a few degrees even of non-level condition are just simply SMALL when compared to what results from the lack of precision that most all of us can regularly achieve with our anti-skating force settings. My recommendation is to not sweat the leveling thing too much..." If you have a pivoted style arm. Hope it helps.
Cheers, John
orig post: http://www.audiocircle.com/index.php?topic=82514.msg1335386#msg1335386
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I suppose the angle that the needle tracking in the groove (due to the pull of gravity on the arm etc) could possibly have some implications, but as others have said, as long as the table isn't grossly off kilter, I think you're really splitting hairs.
.......though if you have $100,000 table, then hell yeah, I'd expect the dealer to come to my home and set it up PERFECTLY level, so that the needle could split hairs all day long.
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I just discovered in the last few days my table was slightly out of level. I suspected it was fairly incremental.
Ill try to get a bit tighter and see if noticeable.
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Don't underestimate the benefit of perfectly level, even with a gimbaled arm. Differences might be hard to quantify, but with a "good" set-up you'll hear it.
What if you have a unipivot?
If the record is on an angle much more than anti-skate is affected. You're putting more force on one groove wall than the other. This will give not only unbalanced sound, it encourages mistracking.
What's the big deal? Level it. You'll be glad you did. BTW Harbor Freight has a nice bubble level for under a dollar.
neo
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Do you level the platter or the pivot point of the arm? Or is it one in the same?
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Most of those with fairly ordinary pivoted arms actually do not. The degree of offset of lateral forces that might arise from a few degrees even of non-level condition are just simply SMALL when compared to what results from the lack of precision that most all of us can regularly achieve with our anti-skating force settings. My recommendation is to not sweat the leveling thing too much..." If you have a pivoted style arm.
This was my gut feel when asking the question. It's not like my turntable is grossly mis-leveled.
Neo,
Thanks for the channel imbalance comment. And possible mis tracking. Other than that, what specifically does one get from a perfectly leveled turntable? These things are hard to quantify in real terms.
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Don't underestimate the benefit of perfectly level, even with a gimbaled arm. Differences might be hard to quantify, but with a "good" set-up you'll hear it.
What if you have a unipivot?
If the record is on an angle much more than anti-skate is affected. You're putting more force on one groove wall than the other. This will give not only unbalanced sound, it encourages mistracking.
What's the big deal? Level it. You'll be glad you did. BTW Harbor Freight has a nice bubble level for under a dollar.
neo
It is also hard on the platter bearing, and this alone may be one of the most important parts to getting a table level. It's almost no effort to hold something in your hand that is level and balanced, try to hold something off center....
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I'll start this (then hopefully a turntable setup "Guru" will pick up where I leave off) by saying you are trying to preserve the geometric physical interface of the path that your stylus has to travel through the single continuous groove of your LP.
The whole point of getting things as level as possible is so that the angle that the stylus is tracking changes at a very gradual rate through
the entire play span of the LP from the lead in all the way to the lead out groove. The basic reason you are taking this much care is so that most of the work of maintaining the tracking interface with LP surface it accomplished by the physical laws of gravity as it applies to your tonearm holding down the stylus in the groove without having to add too much mech anical anti skating force to keep the stylus from lifting from the groove from the natural friction of playing an LP causes on the stylus tip.
There is actually an "acceptable" level to how level the turntable can be, but I don't have much insight on just where that is. (You don't have to achieve Micron Microscope levels of precise levelling,but it's important to try for the best result you can here)
(I'm extremely slow at typing,so just ignore my saying "I'll start by...etc")(Sorry)
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What's the big deal? Level it. You'll be glad you did.
neo
Well said, Neo. Invest a little effort to level it, and then enjoy knowing that you've made it as close to perfect as you ever need it to be.
These things are hard to quantify in real terms.
I can quantify these things for you but will refrain for now. To ensure that your groove side wall forces are well balanced, in audio passages, you'd be doing better to focus on your anti-skating adjustments. Setting it by the tonearm scale will likely leave an imbalance that is much greater than a poorly leveled table. Get something like a Fozgometer setup or make very careful magnifier views of the stylus while playing audio to look for side deflections from free state. Anti-skate adjustments are likely discussed at length on other threads. Neo?
Yers, John
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As a user of an Air-bearing TT and tonearm I level the table with a torpedo level from front to rear and level the table from left to right with the tonearm itself. With zero tracking force applied and the tonearm floating freely, when the table is perfectly level the tonearm shows no tendency to drift either to the left or the right. The bubble levels I can afford to buy are too poorly made to establish a level condition of sufficient accuracy for the tonearm.
It might be possible to use a modification of this technique with a pivoted arm. If the tonearm was free floating with no anti-skating applied it should show no tendency to drift in any direction. If the table is not level from left to right the tonearm should tend to drift towards the low side if the bearing friction is low enough. This would depend a great deal on the tonearms bearing friction.
Scotty
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It is also hard on the platter bearing, and this alone may be one of the most important parts to getting a table level. It's almost no effort to hold something in your hand that is level and balanced, try to hold something off center....
+1 This is what I understood as the main reason for a level table, the bearing. The variations in azimuth and anti-skate bias adjustment are surely much greater than the variations from slightly off level to perfectly level. But rumble and bearing wear could be significantly increased even slightly off level.
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My Trans-Fi TT has a magnetic bearing and air bearing linear arm, so level is extremely critical. After fiddling with various bubble and torpedo levels, I bought one of these 8" Starrett levels and it is a joy to use. It was worth every penny to me and have confidence my setup is dead on.
(http://www.audiocircle.com/image.php?id=71817)
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A very nice level indeed. Do we really need a $150 level for normal turntables with pivot arms and oil bearings? I think it might be a little beyond the scope of the op, a person new to vinyl without an air bearing tonearm. Despite it being a really nice looking tool.
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Well,,, I'm not all that new to vinyl. I'm just asking a newbie question for verification. I will admit that I am mechanically challenged..... :D
I had not considered the bearing performance vs. leveling before this post. I know first hand that a better quality bearing in the same turntable sounds better, so it only makes sense to get the best performance out of the bearing that you are using. If leveling does that, then it is worth revisiting.
Appreciate the help so far. :thumb:
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The physics involved at the vinyl/stylus interface is amazing (as is the fact that it works as well as it does). Instantaneous stresses in the vinyl would cause structural steel to yield and related temperatures are way beyond the melting point of vinyl. So keeping everything aligned is critical. Level should be checked in two directions (at 90 degree angles from each other). Old floors, wall mounted supports, etc. for example can all be off significantly. Quality of the level is important as really tiny/cheap ones aren't worth bringing home (I'd use a marble or ball bearing first).
Being a good citizen, I'm sure your gravity bill is fully paid in full. So a tilt would:
- require additional tracking force to keep the stylus in the groove, leading to extra vinyl/stylus wear
- induce extra additional stresses/melting of the vinyl on the side the stylus is leaning into
- cause additional wear on the stylus/cantilever (it would be skewing the proper anti-skating mechanism of the tonearm)
- as mentioned eventually cause wear to the platter and tonearm bearings
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A very nice level indeed. Do we really need a $150 level for normal turntables with pivot arms and oil bearings? I think it might be a little beyond the scope of the op, a person new to vinyl without an air bearing tonearm. Despite it being a really nice looking tool.
I bought a bunch of dollar store levels - smaller torpedo levels. Not one of them was actually level. Put the level on a non-level surface and take a reading, then turn it around and it should be the same. If you get different readings which is right?
I mentioned earlier that I picked up a round bubble level at Harbor Freight store for under a dollar. I bought another along with it, a small one with levels at 90°. The round one is perfect. Turn it around in any direction and it reads the same. This is an in-store only close-out - brand name Pittsburgh. That must be Pittsburgh, China.
BTW, most of the vinyl melting stuff has been debunked by a record playing physicist. Still, it's better when level.
neo
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I bought a bunch of dollar store levels - smaller torpedo levels. Not one of them was actually level. Put the level on a non-level surface and take a reading, then turn it around and it should be the same. If you get different readings which is right?
Exactly. I should add that TT's and audio aren't the only thing I use it for :wink:
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A very nice level indeed. Do we really need a $150 level for normal turntables with pivot arms and oil bearings? I think it might be a little beyond the scope of the op, a person new to vinyl without an air bearing tonearm. Despite it being a really nice looking tool.
You can find them at flea markets and on ebay for a fraction of the new price. Since they are adjustable you don't have to worry about the Starretts not being true; a great feature IMO.
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Getting the forces even on the platter bearing?... certainly sounds real good. However, most TTs (most belt units and rim drives, etc) apply single direction side forces to the platter and bearing through the belts or idlers, that are greater than those that would result from gravity acting on a significantly mis-leveled assembly. A few designs, such as axial motor direct drives or balanced opposing belt pair drives, would get away from that condition.
So once again, for best enjoyment YES work some to level your TT. For best enjoyment also, don't overthink it too much. :)
Cheers, John
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Do you level the platter or the pivot point of the arm? Or is it one in the same?
I recently had the experience of having my tone arm drop onto the record and then sweep all the way to the label across the grooves. My audio doctor suggested that I might just need a new needle and cartridge. At a local record shop where they can sell you new needles and cartridges, the technician put my turntable on his level surface. He soon found out that my turntable was not level. He used a sharpie pen on a CD case to make a mark at the top of the left side which was low. He brought the CD case over to the right side and the mark appeared to be 1/4" lower. When I got home I raised the left sideof the entire turntable by 1/4" and now I no longer have the sweeping tone arm and marvelous tone from all my records that had been slipping a lot lately.