STD 305M with SME Series 3 Arm, Need Protractor
- Thread starter Joe Dawson
- Start date
Your welcome Nat. The two holed version is recommended with the
stevenson protractor, from what other(s) have recommended. I downloaded/printed
from vinyl engine.The photos are shown in post #15 and the cartridge does not line
up properly at all.The SME looks better to me, calculating in my mind.
Tech, my TT looks exactly, exactly like yours except I cannot get either protractor to be
really that accurate, although the SME seems much closer than the stevenson.
The SME requires me to have the arm base fully touching the bubble (yours is not)
and it still not that accurate.
I was wondering which protractor did you use??
joe
stevenson protractor, from what other(s) have recommended. I downloaded/printed
from vinyl engine.The photos are shown in post #15 and the cartridge does not line
up properly at all.The SME looks better to me, calculating in my mind.
Tech, my TT looks exactly, exactly like yours except I cannot get either protractor to be
really that accurate, although the SME seems much closer than the stevenson.
The SME requires me to have the arm base fully touching the bubble (yours is not)
and it still not that accurate.
I was wondering which protractor did you use??
joe
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technome
New Member
I used the SME protractor that came with the tonearm. My arm had the single hole head shell, but the spindle to pivot distance is the same.
The protractor you need should measure 60mm from the centre of the spindle hole to the centre of the stylus grid.
Now I look at your photo of the arm in post #5, it looks like the tonearm body assembly might be too far forward on the bearing yoke. That could be an optical illusion, though. Have you checked everything is assembled properly?
There's a service manual at vinyl engine:
https://www.vinylengine.com/library/sme/series-iii.shtml
The protractor you need should measure 60mm from the centre of the spindle hole to the centre of the stylus grid.
Now I look at your photo of the arm in post #5, it looks like the tonearm body assembly might be too far forward on the bearing yoke. That could be an optical illusion, though. Have you checked everything is assembled properly?
There's a service manual at vinyl engine:
https://www.vinylengine.com/library/sme/series-iii.shtml
Hi Technome,
Attached are two photos, one of top of tt (arm back half way from full forward),
and the other showing 117 null point discrepancy.
I measured the spindle to null point on both the SME lll and Stevenson protractors
and they measured 61mm and 60mm respectively.
Yes, the arm is maximum forward bumping on the bubble/level. I made a little mistake,
both the SME and Stevenson are pretty close to proper at the 61mm and 60mm with arm
maximum forward.
At arm half way back via gears, at 60mm, the cartridge is nearly 2 lines off. At 117mm null point,
the needle is off a good 25mm (1 inch). (See photo STD top117mm).
I believe that was Stevenson's goal, minimum distortion at inner grooves. But an inch
off at 117mm seems way off isn't it?
Again, Thanks for your time and efforts Gentlemen.
joe
Attachments
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totem
Addicted Member
Almost see post #14
*Regardless what you read on VE.
Joe notice where tech's arm is positioned in the sliding base post #20, the middle position gives adjustment both fore and aft
while not always possible its the ideal location for max adjustment that an OEM would
shoot for.
Having to be positioned all the way at either ends begs the question why.
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technome
New Member
Joe,
You need to have the grid positioned under the stylus point each time you look at one of the two alignment points.
I have attached a couple of photos. Ignore the fact that this is an SME 309 on an Oracle. And ignore that I am using a circular alignment disc and using the Baerwald alignment points. I could not find my vinylengine printouts. The principle is the same but you need the Stevenson points.
At the inner point, line up your stylus point at the centre of the grid with the protractor over the spindle.
Then check the outer point. You will need to rotate the platter and the protractor to do this. Once again, place the stylus tip on the centre of the alignment grid, like so.
At both positions the stylus body should align with the grid lines, but it doesn’t need to be exact. Near enough is good enough, but it should not be a long way off.
If you have your tonearm in its mid position, it should be good enough.
You need to have the grid positioned under the stylus point each time you look at one of the two alignment points.
I have attached a couple of photos. Ignore the fact that this is an SME 309 on an Oracle. And ignore that I am using a circular alignment disc and using the Baerwald alignment points. I could not find my vinylengine printouts. The principle is the same but you need the Stevenson points.
At the inner point, line up your stylus point at the centre of the grid with the protractor over the spindle.
Then check the outer point. You will need to rotate the platter and the protractor to do this. Once again, place the stylus tip on the centre of the alignment grid, like so.
At both positions the stylus body should align with the grid lines, but it doesn’t need to be exact. Near enough is good enough, but it should not be a long way off.
If you have your tonearm in its mid position, it should be good enough.
technome
New Member
Yeah, but the difference of 0.06mm is trivial in this context.
I can't believe I can be so s...... Got it looking very good and arm is notnot fully forward anymore. Just to think
I knew this info/TTs 40+ years ago leaves me a little depressed. Getting old is not for the faint of heart.
I am checking the TT out in a few hours, after all is warmed up.
Thanks Technome and gents for being patient with me.
joe
I knew this info/TTs 40+ years ago leaves me a little depressed. Getting old is not for the faint of heart.
I am checking the TT out in a few hours, after all is warmed up.
Thanks Technome and gents for being patient with me.
joe
Unsent until the issue was sorted out, but what the heck - it might help another owner.
I don't see the point of using a downloaded or third party protractor rather than the the SME provides. I assume the reason people buy SME arms is that they trust that the company's engineers and production staff are among the most capable in the world. So why wouldn't you trust their protractor? You download or buy a protractor - do you know it is scaled exactly correctly, or that the people who made it knew what they were doing?
In the back of my mind I come back to the small plastic rulers I was supplied when teaching Biology in the 90s - I was having students determine the field of vision of their microscopes, and their results were terrible. It turned out that the cause was those rulers, which, despite being bought from a school scientific supply place (and so were not cheap - but the quality and pricing of school supplies is a different issue), were sourced from the cheapest manufacturer and one, who apparently was unclear on the length of a centimeter, and therefore, a millimeter.
I don't see the point of using a downloaded or third party protractor rather than the the SME provides. I assume the reason people buy SME arms is that they trust that the company's engineers and production staff are among the most capable in the world. So why wouldn't you trust their protractor? You download or buy a protractor - do you know it is scaled exactly correctly, or that the people who made it knew what they were doing?
In the back of my mind I come back to the small plastic rulers I was supplied when teaching Biology in the 90s - I was having students determine the field of vision of their microscopes, and their results were terrible. It turned out that the cause was those rulers, which, despite being bought from a school scientific supply place (and so were not cheap - but the quality and pricing of school supplies is a different issue), were sourced from the cheapest manufacturer and one, who apparently was unclear on the length of a centimeter, and therefore, a millimeter.
Well, I thought about it, the Stevenson is a download from VE Vinyl Engine. When printed out, the dimensions measured correctly
and it has two nulls, rather than one. My TT sounds clearly better on a variety of selections, than after using the SME protractor.
keep on truckin
joe
and it has two nulls, rather than one. My TT sounds clearly better on a variety of selections, than after using the SME protractor.
keep on truckin
joe