Ok, I've been wondering, can someone please explain this 92 degree SRA stuff to me please?

M

MusicDirector

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I've been hearing and reading a lot lately about this 92 degree SRA stuff and I don't understand how one checks and adjusts it. About the only thing I grasp is what the acronym stands for (Stylus Rake Angle...and that took me 3 months to figure out) and the concept behind it.

Here's the thing: I strictly use legacy/vintage tables. I just prefer them and like them over the new stuff, sorry. (Not that some of the new tables are not pretty, I think some are drop dead gorgeous, but it's not about the looks).
Anyway, I use a Pioneer PL510A and a Denon DP-47f.

My questions are:
1) Does SRA even apply to using vintage/legacy tables?
depending on that answer:

2) How does one check for the angle degree?

3) How does one adjust for it, if needed?

Those are the things that are never addressed in any articles on this subject I have ever read.
I wish I could ask Michael Fremer about this as well since he was the first one I read about regarding this.

Can anyone enlighten and educate me in easy to understand language on this? By that, I mean just don't over-use acronyms, as it takes me a very long time to figure them out and I get confused easily with them. Don't get overly technical on me either please.

Thank you,
Eric
 
MikeCh said:
Scroll down to step 5:

Setting Up A Phono Cartridge | The Absolute Sound

I'm sure Andre can and will answer any questions you have once you read thru the process.

Fremer does have several articles explaining SRA too:

Set-Up Tips | Analog Planet
Click to expand...

Thanks Mike. Why did I not see that part of the article from Fremer? At any rate, the article from the first link helped too.
Ok, getting a USB microscope is not hard and doesn't cost all that much (One can be had for $70 to $100 that is just as good as any other).
The only sticking point that remains it adjustment, but that is sort of cleared up as well. In my case, there are now two reasons I need not concern myself with SRA. (I'm not having any sound issues anyway, was just curious about it).
1) The article says it is not for the faint of heart....I'm the faint of heart.
2)More practically though is the fact that on my tables there is not way to adjust for it. The tonearms can not be raised or lowered. This appears to only be for Unipivot tonearms, not stock tonearms on vintage tables.

Thank you.
 
There's been a copule of posts about inaccurate measurements with the USB microscope, so you need to be very precise.

- The USB microscope has to be set exactly 90degrees to the side of the stylus. Any amount of offset can change what you think you are actually viewing.
- You have to know where to draw "the line" through the stylus tip based on the type of cut it has. Some are right up through the center, others are along the back edge, etc.
- You need some way to actually measure the angle while you are looking at it through the USB microscope.
 
MusicDirector said:
Thanks Mike. Why did I not see that part of the article from Fremer? At any rate, the article from the first link helped too.
Ok, getting a USB microscope is not hard and doesn't cost all that much (One can be had for $70 to $100 that is just as good as any other).
The only sticking point that remains it adjustment, but that is sort of cleared up as well. In my case, there are now two reasons I need not concern myself with SRA. (I'm not having any sound issues anyway, was just curious about it).
1) The article says it is not for the faint of heart....I'm the faint of heart.
2)More practically though is the fact that on my tables there is not way to adjust for it. The tonearms can not be raised or lowered. This appears to only be for Unipivot tonearms, not stock tonearms on vintage tables.

Thank you.
Click to expand...

Find a JVC 7045 arm! :)
 
BobM said:
There's been a copule of posts about inaccurate measurements with the USB microscope, so you need to be very precise.

- The USB microscope has to be set exactly 90degrees to the side of the stylus. Any amount of offset can change what you think you are actually viewing.
- You have to know where to draw "the line" through the stylus tip based on the type of cut it has. Some are right up through the center, others are along the back edge, etc.
- You need some way to actually measure the angle while you are looking at it through the USB microscope.
Click to expand...

AutoCAD works very well for your first and third concern.
 
BobM said:
There's been a copule of posts about inaccurate measurements with the USB microscope, so you need to be very precise.

- The USB microscope has to be set exactly 90degrees to the side of the stylus. Any amount of offset can change what you think you are actually viewing.
- You have to know where to draw "the line" through the stylus tip based on the type of cut it has. Some are right up through the center, others are along the back edge, etc.
- You need some way to actually measure the angle while you are looking at it through the USB microscope.
Click to expand...

Whew! I'll never have to worry about SRA then with all that, no matter what table I'll ever have then. My take away is that one has to be an engineer with a Phd to even begin to know how to measure SRA let alone anything else.
There is no way in hell I could even begin to think about any of this. I'll take my chances.

Then again, I'll never own a cartridge priced more than $200 anyway. I just don't see or get the point in it. I have a $400 cart (Ortofon 2M Bronze) on my Denon now and while it's alright and everything, I think it's over-priced by a good $100 for what it is. So no matter what SRA will never be a real concern for me. That's good to know.
 
You can regard the 92 degree angle as a compromise- an average. The reason is that all LPs are cut slightly different.

When we install a new stylus on our cutterhead, the big deal after that is to get it to cut properly, that is to say without distortion and without noise. In the process you find that even though you know how the cutterhead was set up before, its not that way with the new stylus, even though they all install the same way in the head. The reason is due to slight variances in the styli themseleves. As a result, the 92 degree angle is not what the engineer is looking for- he is looking for the right angle such that it works. That is usually pretty close to 92 degrees.

The point in looking at your setup to see that it is correct is in part to make sure that your cartridge is in fact OK. Some cartridges have the stylus incorrectly mounted and can't be set up properly. So its a good idea to take a look.
 
atmasphere said:
You can regard the 92 degree angle as a compromise- an average. The reason is that all LPs are cut slightly different.

When we install a new stylus on our cutterhead, the big deal after that is to get it to cut properly, that is to say without distortion and without noise. In the process you find that even though you know how the cutterhead was set up before, its not that way with the new stylus, even though they all install the same way in the head. The reason is due to slight variances in the styli themseleves. As a result, the 92 degree angle is not what the engineer is looking for- he is looking for the right angle such that it works. That is usually pretty close to 92 degrees.

The point in looking at your setup to see that it is correct is in part to make sure that your cartridge is in fact OK. Some cartridges have the stylus incorrectly mounted and can't be set up properly. So its a good idea to take a look.
Click to expand...

Usually having to cant the cartridge 30 degrees is a good tip off! :)

Good to see you here Ralph!
 
Personally, I think this 92 degree SRA thingee is a made up specification that made Mickie Fremmer the be all and end all analog guru. Reading all his reviews he never ceases to mention 92 degrees. If there were some cartridge standards, I might agree. But I have always went with what sounds better. If I can’t hear a one or two degree difference, than it doesn’t make a difference in my book. I have never read one manufacturer state that their cartridge should be set up with a 92 degree SRA. 90 degree maybe, the front profile at a perfect right angle to the record surface maybe. The bottom of the cartridge body parallel to the record surface maybe. And many others. I start out with the cartridge manufacturers recommendation and go from there. There is enough sweat on the platter after I set up a new cartridge without resorting to a USB microscope. And let’s not forget what the poor stylus tip and cantilever go through during setup. It’s a miracle it works at all after a few slips and bounces.
 
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