Tonearm Alignment Protractor

[daiwok]

Yeah, with an RS-A1 you just stick it anywhere... don't even need a protractor. ;D

anywhere ?  :P

[rfgumby]

anywhere ?  :P

Well, anywhere on the top of the turntable...

All right, I admit I'm just teasing Ian.

[haydn]

I am using the Lofgren A points with good results. Always open to advise, if someone says the Denon 103R is better with the B points or the Baerwald points happy to give it a go.  

Being relatively uninitiated as to all these technical differences between the various alignment methodologies, I didn't know what the difference between the Lofgren A and B points were.   ???

So, for all those in the same position as I, Lofgren's "A" alignment minimizes peak distortion while his "B" alignment minimizes RMS distortion. The advantage of using Lofgren's "B" alignment is lower tracking distortion, particularly during more playing time - i.e. lp's rather than 45's - at the expense of slightly higher distortion at the beginning and end of the record. On the other hand, Lofgren's "A" alignment minimizes and equalizes the distortion peaks at the innermost groove, in-between the null-points, and at the outermost groove.

Stevenson "A" uses the same equations as Lofgren but with a different goal, i.e. zero distortion at the inner groove. Ultimately, the difference between these alignment methods is all about different null points and the type of distortion you're prepared to live with. 

Graeme Dennes over on vinylengine says that Stevenson's goal (for the "A" alignment) was to minimise (in fact to make zero) the weighted tracking error (WTE) and the resulting distortion at the specified inner groove radius.  However, the WTE and the distortion occurring over about 75 percent of the record playing time is greater than that which occurs under the Lofgren A alignment for the same conditions (ie arm length and groove radii). He says Stevenson A alignment is only significantly better than the Lofgren "A" alignment during the last 3-4 mm of the record playing surface (usually less than one minute of playing time).

Always open to advise, if someone says the Denon 103R is better with the B points or the Baerwald points happy to give it a go.   

There is, apparently, no difference between Baerwald and Lofgren "A". So, does anyone use Lofgren "B"? More importantly, I suppose, is can you hear a difference?
h

[willbewill]

Well, anywhere on the top of the turntable...

All right, I admit I'm just teasing Ian.

Looks great going around on the platter - but sticks in the groove

[daiwok]

Back to protractors, no matter which one you use, you will get an error, that is a fact. Minimising that error down to 0.5mm, well good luck, you will need some special jig and a magniflying glass to see it. Why has no-one ever made a jig for setting up carts ? something that you can use like a vernier to makde ultra fine adjustments, then fix the damn cart while you try and tighten the bolts without is moving around ! Surely that is worth paying for compared to some of these USD 250 protractors ? of course you don;t have these issues with a linear tracker - do you ?  ;D :P

ok - off to the patent office now  ;D

[haydn]

David, we already know you've got young ears and as you're younger than I, probably better eyesight.   So I'm sure knocking up a new protractor as you've suggested shouldn't be too difficult for you;D

Once you've got that patent, I'm sure there are a few us that'd be willing to stick an order in.....
h

[jon]

There is, apparently, no difference between Baerwald and Lofgren "A". So, does anyone use Lofgren "B"? More importantly, I suppose, is can you hear a difference?

There is no difference between Lofgren A and Baerwald? That does surprise me. I have all three templates and their is a difference between the two. Of course the end result might be same and therefore it is the method to achieve it that is different!

[daiwok]

Same difference Jon ! 

[jaspert]

Ok, Jon's recently got himself a vintage Dennesen Soundtractor and Nic's said he has one of Yip's MInt Tractor's but hasn't used it yet. There's a fair bit of praise for the Mint over at audiogon, particularly over a Feickert or a Wally.

Has anyone got or used a Wally, a DB , Chpratz, a Feickert Universal or Galibier Protractor  or any other - to align your tonearm? Nic said Yip already has the spindle size for a L75, so some of you  may have compared it to one (or both?) of the above? Anyone got a personal favourite - and why??? 
h

I used to use a cheap Ortofon alignment protractor costing $4. When an opportunity to get a mint Feickert Universal Protractor for US$115 came up, i snatched it as it's quick tool to setup and useful with different tables and different arms.  Now recently, i've also bought a Mint LP Best Tractor specific for my new Graham Phantom tonearm/turntable combination and this precision arc protractor is a real pain in the bum to setup. I had a brief go at it late last night, not enough time and too tired to carry through so will get back here when i have it nailed.

[daiwok]

I used to use a cheap Ortofon alignment protractor costing $4. When an opportunity to get a mint Feickert Universal Protractor for US$115 came up, i snatched it as it's quick tool to setup and useful with different tables and different arms.  Now recently, i've also bought a Mint LP Best Tractor specific for my new Graham Phantom tonearm/turntable combination and this precision arc protractor is a real pain in the bum to setup. I had a brief go at it late last night, not enough time and too tired to carry through so will get back here when i have it nailed it.

Let us know if you hear any difference once you nailed it  : BTW Jasper - how about posting your system when you get the chance 

[rbakedq]

I am using a Turntable Basics protractor, with a piece of thread added to make pointing at the tonearm pivot very precise. It is a Baerwald  two point universal mirrored protractor, so you eliminate parallax error.  Also, aligning the cantilever to the grid is made much easier by looking at the refection in the mirror.  The main trick I have found for getting accurate results, using the TT Basics protractor or the any of the many paper protractors I have downloaded, is good lighting.  What I do is use a bright LED flash light.  The trick is to point it at the stylus in just such a way that the stylus glows; it then becomes much easier to align to the marks.  When using a mirrored protractor, always make sure to eliminate parallax error;  ie. be sure the line you are going to use is perfectly aligned with its reflection. After immobilizing the platter and pointing the site line at the pivot, I start by looking from the side and put the stylus on the main line.  I then look from the front to see if i am right or left of the center grid line, and move the cartridge  back and forth until after repeating the last three steps the stylus is perfectly centered, at the sane time aligning the cantilever with the grid lines.  Tighten the bolts check again and most likely start over.  In all it takes me about ten minutes.

[rfgumby]

I have a Turntable Basics protractor as well.  With those, I usually tape the protractor to the platter , and the platter to the plinth so nothing moves out of alignment.  That string to help orient it exactly the right way is a great idea Rich!

[rbakedq]

Scott: if you look at the first picture you can see I use a wedge made out of balsa wood to immobilize the platter.  I sometimes tape the protractor to  the platter mat, but I mostly just recheck the alignment to  the pivot. 

[haydn]

It's interesting that almost all these arc protractors use Baerwald or Lofgren "A" alignment. Looking at that Turntable Basics protractor, it certainly appears easy to use - but then the Mint is too by all accounts. It's obvious, too, from some of the other forums that those that claim they use `Baerwald/ Lofgren "B" ` are confused because the alignment null points are not identical.

I came across another two protractors - the Schon http://www.tnt-audio.com/accessories/schon_e.html and the TNT http://www.tnt-audio.com/sorgenti/analogue_bites_e.html - over on TNT-Audio and both these use the same alignment methodology. On the Schon link, there's an interesting use of a piece of refillable pencil lead to assist in alignment whilst on the latter, for those with straight arms, there's a real nifty piece of plastic that assists in setting VTA that I might just have to get. 

Is there no one that uses - or has at least tried - Lofgren "B" and can report either less or more distortion? 

Always open to advise, if someone says the Denon 103R is better with the B points or the Baerwald points happy to give it a go.  

Jon, over on Dogogo http://www.dagogo.com/DenonDL-103.html, there's a suggestion that Stevenson alignment rather than Lofgren "B" may be better for the Denon 103 than Baerwald/Lofgren "A".  This may be because it was used in review with a Japanese tonearm and on Audiokarma, http://www.audiokarma.org/forums/showthread.php?t=155358&page=4, one contributor claims Japanese turntables use Stevenson null points.

Bet Lenco never used Stevenson! ;D

[jaspert]

Let us know if you hear any difference once you nailed it  : BTW Jasper - how about posting your system when you get the chance 

Too busy today with other chores to finish the alignment with Mint :-\
but I will post a pic of my system later.

I took some pics tonight. As you can see the Mint arc protractor has a really fine line and you really need a magnifying glass and 10x loupe to check that you are tracing the arc and aligned properly. Parallax error is taken care off too. it's about precision at the miniature level.

Pic of the Feickert.


Pic of Mint Arc Protractor with the free illuminated magnifying glass and Peak x10 loupe( optional $10).


Front side on pic taken with my  Canon macro lens.


Side on pic.