[Napalm]

[...] Napalm dismisses Mikey and the demag issue without ever mentioning any research[...]

Here you go:

Introduction to terms:

http://www.ndt-ed.org/EducationResources/CommunityCollege/MagParticle/Physics/MagneticMatls.htm

Magnetic properties of materials:

http://www.kayelaby.npl.co.uk/general_physics/2_6/2_6_6.html

Vinyl is not a ferromagnetic material period.

Nap. 

[BobRex]

Vinyl is not a ferromagnetic material period.

Yeah, I've had college physics and I know that vinyl isn't ferromagnetic, so does Mikey for that matter.  So maybe, just maybe something else (Oh, I dunno, the blackening agent (lampblack IIRC)?) is. 

Are you perhaps dismissing the wrong thing?

[Syrah]

Mikey earns a living giving audio advice.  I earn a living giving legal advice.  When I give it for free, people usually say thank you, even when they don't agree with it because they know I'm taking time out of my busy day to try to help them. 

Thank you Mikey!  I think most of us in this forum appreciate your input, even if we are (perhaps rightly, perhaps not) cynical and challenging of all advice.

[Napalm]

Yeah, I've had college physics and I know that vinyl isn't ferromagnetic, so does Mikey for that matter.  So maybe, just maybe something else (Oh, I dunno, the blackening agent (lampblack IIRC)?) is. 

Are you perhaps dismissing the wrong thing?

Yes there is a scientific explanation, it's called "placebo effect".

Nap. 

[Wayner]

Thanks Michael for stopping by. I hope you continue contributing to this thread as I think there is a lot of interest in the subject and for the most part, the group (as a whole) are eager to learn new stuff.

Now, to my hesitation on the USB scope. It's just that things are so damn small. I got from your article that the measurements of SRA should be done with the stylus in the groove, with VTA set to the desired weight. Now, that doesn't leave much of the stylus in viewing range. If I print out a very small (but to scale) paper protractor, and for now, try to align that with an imaginary center-line of the stylus, I fear, again because everything is so small, that I'm still guessing. Although I think the scope would lessen the error rate, maybe bringing it within a 1/2 degree. I'm just wondering if there is a better way, like say with a mirror?

Ericus Rex then brings up a good point. If we set SRA with a thinner or thicker then normal LP, are SRA is going to change, and that may prove the need for multiple VTA settings for our tonearms.

One other point that I want to ask you is, are there any cartridge manufacturers that have "pre-loaded their designs to give the correct 92 degree ARS with a flat tonearm (to the record surface)? The reason I ask is that a few of mine (2) of 6 TTs look like they migh well be in the 92 degree zone, and I know the tonearms are parallel to the record surface (with stylus in the groove).

BTW, I met you at last years RMAF at the AVA/Salk Room (Thanks for the photo op).

Wayner

[Wayner]

For the rest of the group, I started this thread in hopes that Michael would jump in and he has done so. Like everyone else, he (as we all) needs to be treated with some respect, please. You can disagree with him, but I want to learn about setting my SRA properly and this is the MAN.

Thank you.

Wayner

[skunark]

Here you go:

Introduction to terms:

http://www.ndt-ed.org/EducationResources/CommunityCollege/MagParticle/Physics/MagneticMatls.htm

Magnetic properties of materials:

http://www.kayelaby.npl.co.uk/general_physics/2_6/2_6_6.html

Vinyl is not a ferromagnetic material period.

Nap. 

Napalm,

Perhaps this is nothing more than static electricity build up on the vinyl as you take it out of the sleeve or when you drag your feet over the rug as you place it on the turntable?   Vinyl is really no different than a PVC pipe and I do remember those static electricity experiments way back in grade school where PVC can hold a charge.  Or is the claim that there are ferromagnetic impurities in the material that might need to be dealt with?     (I feel like I'm coming in late on this topic)

I will say that after reading several of Napalm posts and reading several of MF's reviews, both are passionate about this hobby and as with anything, you do have to step back and make your own judgment.  I won't blindly take anyone's word either...   No offense MF, but I do tend to read your articles with a bit more caution as lately it appears you have favorites or perhaps get a bit heated in the review and choosing  equipment with the same initials seems like a conflict of interest  ...just kidding about the initials part...

[Wayner]

I have spent the entire afternoon with pencil in hand, CAD at the helm and experimenting to no avail. The ability to see the stylus is the problem, as is the determining the position, either in free air, loaded on the arm with desired VTA or even trying to find specs on the SRA from manufacturers.

I have become weary. Tomorrow, I may try to use some recording software in my computer, to see if I can graphically see change in SRA while recording, hoping that optimum SRA will cause some increase in volume on the recording. I will use some all band white noise first, but later, may try some specific frequency bands. I will adjust the SRA on the fly while recording, marking positions as I go. Until then, I'm going to have a few brews and spin some long needed vinyl.

Wayner 

[hesson11]

If we set SRA with a thinner or thicker then normal LP, are SRA is going to change, and that may prove the need for multiple VTA settings for our tonearms.

One other point that I want to ask you is, are there any cartridge manufacturers that have "pre-loaded their designs to give the correct 92 degree ARS with a flat tonearm (to the record surface)? The reason I ask is that a few of mine (2) of 6 TTs look like they migh well be in the 92 degree zone, and I know the tonearms are parallel to the record surface (with stylus in the groove).

In his video on turntable set up, Michael says yes, records of varying thickness will change the SRA. He suggests setting it for record thicknesses in the middle range and not worrying about thinner or thicker records—unless you're absolutely maniacal in your pursuit of perfection.

I think one of the most valuable pieces of information any reviewer could provide is whether or not 92˚ SRA is achieved with the tonearm parallel to the record. That would be a great addition to Michael's reviews, if it's possible.

Best of luck with your experimentation, Wayner. More power to you!

-Bob

[Ericus Rex]

I just did a quick calculation and if my math is right the difference in record thickness shouldn't be an issue.  For an arm with an effective length of 237mm there is a difference of 4.17mm per angle degree.  I haven't measured any but I can't imagine a difference of more than 2-3mm between my thinnest and thickest record.

[chosenhandle]

SNIP
 I got from your article that the measurements of SRA should be done with the stylus in the groove, with VTA set to the desired weight. Now, that doesn't leave much of the stylus in viewing range.

SNIP

Wayner

Don't use a record, use a CD. It will provide a flat safe surface for the stylus and yet allow you to see the entire stylus with the camera. Plus you can easily drag the CD to get it into focus with the USB camera.

[Wayner]

Good idea. I have a small mirror that is about the same thinkness and it helps get a better view.

Wayner 

[Wayner]

Did a little test before going to the dentist...

I used the Technics SL-1200 as it has VTA adjustment on the fly. Test record was the Soundcraftsmen Test Record, recorded onto a CD recorder, the Tascam CC-222SLMKII, thru the Van Alstine Insight+ EC preamp.

Track 1 was at the lowest setting, tack 7 at the highest. Each graduation was 1mm. I recorded all band pink noise for 20 seconds on each setting, for each track. After listening to the CD about 5 or 6 times I decided that position 4 (or track 5) had a little tingle on the ears. If I had to do a blind test, I might fail tho.

Funny that this position was about the exact position for parallel to record surface arm. So basically, I have proven nothing. However, Depesche Mode Violator sounds real large dimensionally.

As viewed graphically, all the tracks looked identical.

Wayner

[Jeff K]

If it takes a 4mm change in pivot height to alter SRA 1 degree, then one would expect to see a fairly severe tonearm incline to compensate for for a misaligned diamond.  If the diamond is close to alignment, a little tail up or down ought to do it. Start with parallel arm tube and adjust by ear.

So what else is new?   

[jimdgoulding]

I'll share some of my thumb rules.  Might do somebody some good.  Fold a clean white piece of paper one time to make a tent.  Stand it between you and the spindle.  Where the bottom of the paper intersects with the black vinyl makes for a very visable and straight horizontal line to your side view.  Use a flashlight if need be and a magnifying glass and lower the arm in front of the paper interface.  If your cartridge body is flat underneath, you will see right away how this will help to more precisely set your VTA.  SRA is more difficult.  Grado says for best sound a user might want to drop the back of the cartridge body down one or two degrees.  I've done just the opposite.  Still, I can only guess as to what the SRA is cause I can't begin to see the stylus tip and record surface interface sufficiently.  How the heck do you do that?  To the eye, even with the glass, it appears to be perpendicular with the record.   My tonearm pivot is a bit slightly higher than perfectly straight

The thing about VTA is that the line of the cartridge body may not be the exact same as that of the cantilever tip when depressed.  That may vary a smidge from cartridge to cartridge not to mention that all cartridge bodies aren't flat!  Guys with those probably look at the arm.  The computer guys are probably laughin their heads off but we know what we know and what they don't.
 
Anyway, what I have now with my Grado Sonata sounds the best all around. 

[Wayner]

If it takes a 4mm change in pivot height to alter SRA 1 degree, then one would expect to see a fairly severe tonearm incline to compensate for for a misaligned diamond.  If the diamond is close to alignment, a little tail up or down ought to do it. Start with parallel arm tube and adjust by ear.

So what else is new?   

The problem is, unless you can determine where the stylus is to begin with, you have no idea even if you are going in the wrong direction. SRA can change with VTF, record thicknesses, swapping mats, you get the picture. That is the problem. If I knew my AT SRA was right at 90 degrees with my arm parallel to the record surface, I'd try to find a way to tip the ass end up 7 degrees. This is simple math. But the equation is 4mm + something = something else.

Perhaps even when I changed my VTA, I should have checked cartridge weight, at least I should have half way thru the process.

[BobM]

It can also change with stylus force. More force downward moves the front end of the tonearm downward, compressing the cantilever and tilting the cartridge into a more upright position.

It's all inter-twangled. 

[macrojack]

Don't forget to take atmospheric pressure into account. I have a barometer next to my table so that I know what I'm up against when I do my hourly recalibration. Fortunately it's very dry where I live. I have to pity you guys in humid circumstances who fight condensation on a cold diamond.

Sometimes I wonder what the hobby is, tweaking or listening. I guess I run about 50/50. How about you?

[Wayner]

If my tables are sounding good, I don't screw with them. 3 of them I can't do anything about VTA so they are off the hook. The Technics is my experimental deck as everything is calibrated on it. VTA has a scale so repositioning, even on the fly, is totally easy. It's a great deck to fool around with.

I am starting to conclude that perhaps it's better to have the tonearm ass end up a bit, especially if you are tracking on the high side of recommended range. Bob is right on with his comment about the SRA changing with weight.

I've been beating my head with this thing for a couple of days now, and I just can't come up with a better alternative to buying a USB scope. And I'm not sure that's the answer for everyone anyway. Those that are not geometrically minded, will have problems with it and those that are will have problems with it. An invention is needed here, but I have no resources. If I was still at HTI, I'd use one of their scopes.

So not to beat a dead horse, I really don't know where this thread will end. I'm glad Mr. Fremer jumped in and perhaps it gave us all a thought or an opinion, and maybe some started to experiment with their own VTA. I think I'm going to talk to Frank about this and maybe we can hook up the oscilloscope to the table and maybe we can learn something as we fiddle with the VTA, electrically. I mean we might as well be trying to look at atoms.

W

[jimdgoulding]

Don't forget to take atmospheric pressure into account. I have a barometer next to my table so that I know what I'm up against when I do my hourly recalibration. Fortunately it's very dry where I live. I have to pity you guys in humid circumstances who fight condensation on a cold diamond.

Sometimes I wonder what the hobby is, tweaking or listening. I guess I run about 50/50. How about you?

Macro, you funny.