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In Reply to: RE: Help SRA related posted by Whitesnake on June 25, 2017 at 19:53:55
I suggest you ditch the microscope, Fremer notwithstanding.
It's time to learn to set SRA by ear, rather than by eye. It's really the only way to get it right, and confirm that it is right. Do some research, find an appropriate recording, and listen. People have been doing it correctly this way for decades.
A microscope may get you close, and it may not as you need to align the rake and not the length of the stylus, and the two are often not parallel. The rake may be hard to see.
Follow Ups:
I'm with you, this is not a visual problem. Even with a perfect visual solution, it would still have to be checked against an audio measurement. Like a test flight in a new plane, works on the ground is not the story, and never will be.
I have always adjusted the arm height for best sound, as soon as I got tipped off about it;
Even with arms that weren't designed for adjustment on the fly , the set screw and post types. I know I can't see what's going on, and really don't need to, I am after results over data. My new arm buying targets were easy VTA , and it was a good choice for me. I set it for general playback, but once in a while, it is good to dial it in, so to speak, for a critical listen.
As for Fremer ,meh, I understand that a guy has to make a living , and duty calls, but I lost interest in his advice after he wrote that an anti magnetizing vinyl gizmo has value and I should go get one. Well It started way before that, when I was looking for equipment. I was used to guys talking about rise times and slew rate, and this guy is talking about magic sound and how nobody understands how he does it.
Nt
well long time ago, I acknowleged that records are in no way cut the same. while you adjust your angles to accomodate a particular recording your other recordings will suffer.
So it has always been a compromise. But every now and then a new article appears and I guess I get distracted and back on the hunt for the perfect alignment. except I now have to account for carts that are not mount the same...
As for the microscope well it make everything so clear again lol
Well, do as you wish--no problem here.But what you say about (what are slightly) different cutting angles is just as true if you use a microscope or your ears. Greater problem IMO is the difference in record weights, thicknesses. Depending on your collection, and at least for normal (about 120 gm) records, if you do a search you will find some that have been considered typical and that others have used successfully to lock in SRA. If you adjust, by ear, to one of those you'll be at least pretty close to most others. Most of us, I think, just leave it there, and do not overly obsess.
In any event, you'll never know if it is just right unless you use your ears. Your choice. You can follow the measurement guys or the listening guys. Besides, I have blown up your stylus image and I can't see a rake. Can you? Are you assuming that it's parallel to the straight sides of the stylus, or that it bisects the angle towards the point?
You say your arm is at its limit trying to match some microscope inspired angle. Doesn't that suggest any problem to you?
Edits: 06/26/17
well I can't see a rake either but i got the results by measuring the leading edge angle and then the trailing edge angle. the SRA will be obtained by starting with 180 degrees, subtracting the first measured angle, adding the second measured angle and dividing by two.
John did it differently and got the same results.
You did it something like this:
SRA = 55.05 + 70.42 / 2 = 90.26-degrees
.....
You can't see the rake but somehow you are certain that you know where it is in spite of the fact that there are all sorts of designs when it comes to styli--and the rake may not be where you think it is. In addition the angle of the microscope would affect image of the angle of the rake, if even you could see it. How certain are you that the scope line of sight was precisely in line with the two rakes, neither of which you could see?The pitch of your arm looks unrealistically high and has reached the limit of its travel--but you're OK with that. Or are you?
But you write: "this can't be right"
I haven't seen a word from you that all of this pseudo-science provides a result that sounds good. And isn't good sound what this is all about?
I say, do some research and learn how to set the SRA by ear as it has been done for many decades. It's really not all that difficult. And ditch any advice about leaving it level. It's possible that level could work to optimize SRA, but it's quite unlikely.
Edits: 06/26/17 06/26/17
I like your approach, and I like to think it would be my approach, if I could be bothered to fiddle with my tonearm every time I play a different LP from the one I've just listened to. So, I'm afraid I am one of those "just level it" guys. But may I ask, on average, is your tonearm angled up or down with respect to the pivot, after you have optimized by ear? And with what cartridge bearing what stylus shape is this the case? Thanks.
I am impressed with the depth of understanding you and Flood display on this subject.
The point is to take a record that most people agree is typical of a "normal" 120 gm record and adjust your SRA by ear to it. It's not all that hard to do and far easier and reliable IMO than the microscope method. Look at what Whitesnake is going through, and with all that pseudoscientific advice! From that point on you have a choice of leaving it "reasonably" close to correct for most records, or if you are of such a mind you can try to adjust it for each. Your choice.I disagree with Ralph about the degree of variability in SRA record cutting, at least for older lps, the kind that I listen to and prefer. Ralph, obviously, works now when cutting machinery is 50-60 years old and record production is in the hundreds. Most of what I listen to are much older (and I think better) disks cut when the machines were young, the cutting engineers known by name and proud of their work. They even signed their cuttings. Record productions were then in the hundreds of thousands and that made it worthwhile for them to take the time to get it right. I believe there was less variability in SRA then. They even had test records useful for setting stylus SRA using an oscilloscope, so obviously an expectation of precision.
Edits: 06/27/17
So is your pivot point typically up or down with respect to the headshell, with the typical 120g LP from the good old days, when you are happy with SRA?
On my Audio Technica ART-9 the consensus (on one of the ART-9 threads on Audiogon) is tail up and I heartily agree. On my old Shelter 501, it was tail down.On another forum I persuaded a correspondent who was running his ART-9 perfectly level to raise it in stages and listen. He responded, "A silly little 2mm and this thing sounds world class focused and transparent as well as faster and more dynamic. I am stunned by the difference."
Yet there are "experienced" folks out there counseling to leave all cartridges level, to wit, just another "set by eye, not by ear." The blind leading the blind, or is it the deaf.
Edits: 06/28/17
It really depends on whether you rely purely on a subjective assessment or objective measurement to determine the appropriate settings. A mixture of both is required to optimise the setup.
A knowledge of the tip design is also necessary to understand the sensitivity of the tip to small errors. The ART-7/9 also has a fairly short contact line compared to more advanced tip cuts, so it will be fairly tolerant of arm height variations.
A blanket recommendation of "this cartridge requires tail up" is not appropriate unless the arm is also specified. Also, you are essentially saying "The manufacturers don't make the cartridge correctly". Implying that ALL ART-9 cartridges have the same "fault" which is unlikely.
For example, on an SL1200, the Technics arm will always look tail up because the reference headshell is not designed to sit parallel to the arm tube when mounted - the reference "0" position of the pillar is set high by ~1.5mm when the cantilever is deflected, at which point the headshell/cartridge plane is horizontal and the tail is up. Someone subsituting a different headshell and who doesn't understand all the parameters will end up with an incorrect solution unless he has determined by objective measurement that the SRA is in error.
A mounting tolerance of ±1° on SRA and tip azimuth is quite typical. The correct arm height will depend on the actual tip angle not an arbitrary "tail up".
Is 0.01mm extra on the pillar height tail up enough? Or did you mean 1mm or even 5mm? ;)
Regards Anthony
"Beauty is Truth, Truth Beauty.." Keats
If your SL-1200 tonearm appears to be tail-up when set to zero, you're cartridge is not tall enough. Try a different cartridge.
You didn't read what I wrote carefully enough. Or perhaps you haven't studied the arm carefully enough!
Regards Anthony
"Beauty is Truth, Truth Beauty.." Keats
When most people say tail up or down I assume their reference is from a position of a level cartridge--notwithstanding the level of the length of the arm from cartridge to pivot.Well, I don't know what the manufacturing tolerances of cartridges are, and not being a reviewer I have only used a handful. But as I said, in an Audiogon thread a number of correspondents wrote of finding tail up was optimal for the AT Art-9, and no one reported otherwise. Independently I found this to be the case, as did the correspondent I referred to. Notwithstanding what you say about the rake of the Art-9 I do find it pretty sensitive to SRA/VTA, as do others
Going back to the Shelter, I recall reading a review of it before my purchase and the review recommended tail down. And that is what I found on my own.
Edits: 06/28/17
The recommendation has to be based on an actual measurable parameter.
If a purely subjective approach is taken then you will get quite a wide adjustment range as one person's "too bright" might actually be a flat response which is correctly reproducing the record and the "tail down" recommendation might actually be rolling off the top end due to the introduction of an SRA error. SRA mismatch is analogous to magnetic tape head azimuth in that it introduces scanning loss as well as introducing significant levels of distortion.
I'm not trying to be argumentative - my point is that "Tail Up/down" without specifying the magnitude of the deviation from horizontal is extremely vague!
Regards Anthony
"Beauty is Truth, Truth Beauty.." Keats
Everything you say is logical. Yet still, if there is a consensus of tail up, for example, it is a great time saver if you have a new cartridge in that you will likely find your spot going in that direction rather than the opposite. That's all. Just based on my too small sample of 2.As for measurement, very difficult to measure deviation from level as truly level may not be easily ascertained, some of the difficulties made apparent in your post. Certainly not worth the trouble for me. I do measure deviations from my optimum for most 120 gm records, as for a 200 gm record, using a VPI arm which has a graduated scale.
Edits: 06/29/17
> while you adjust your angles to accomodate a particular recording your other recordings will suffer.I agree! I think you're on the right track using the microscope to set SRA to about 92-degrees. If you do that, theoretically, your SRA should be correct for most of your LPs.
Good luck,
John Elison
Edits: 06/26/17
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