Playing with SRA and VTA - some surprises

Discussion in 'Audio Hardware' started by Strat-Mangler, Jun 20, 2017.

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  1. Strat-Mangler

    Strat-Mangler Personal Survival Daily Record-Breaker Thread Starter

    Location:
    Toronto
    Returned to vinyl in August so I'm still learning every day and today was no exception.

    Did some extensive reading on SRA and how setting it up as close as possible to 92 degrees should be the goal. Using a camera, I was able to see the angle of the diamond and I set the SRA appropriately which took some trial & error but after about 10 min, everything looks perfect on paper.

    Then, I spun a record. Oh, my! This was not what I wanted. Instead of the sound being engaging, full of life, inviting, and cohesive, it fell apart. What I had afterwards was a collapsed soundstage, everything became extremely muddy, the high-end was quite muted, and the mids sounded annoying, quite frankly.

    Since I always give the benefit of the doubt, I decided to take advantage of my VPI Prime's ability to calibrate VTA on-the-fly so I spun a beautifully recorded LP I know like the back of my hand and it sounded terrible. I then went to the table and raised the arm *quite* a lot. The mids and high-end were now amazing but the bass was a little on the shy side. The arm was then brought down a bit and then, the bass was back! The clear and inviting mids and high-end remained.

    So I'm glad I did that experiment even though the end result was somewhat of a surprise. Looking at my stylus, I see the angle of the diamond is more pronounced than the 92 degrees people oftentimes refer to but in the end, it's what the ears hear that is most important ; not adhering to statistics.

    Nevertheless, it was an interesting conclusion. Color me surprised. :)
     
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  2. snorker

    snorker Big Daddy

    Did you use a microscope? It's really hard to judge the angle even with one, but I found it impossible to truly see the contact patch of the stylus with a camera set to macro. It's possible you didn't actually have SRA at 92 degrees when it sounded so horrible.
     
  3. Strat-Mangler

    Strat-Mangler Personal Survival Daily Record-Breaker Thread Starter

    Location:
    Toronto
    Basically, the takeaway is the fact that the angle was obviously wrong (according to the 92-degree theory, anyway) and to fix it, I had to drastically drop the arm down. With my camera, I could see the angle well enough so that I knew I had it set pretty close, if not dead-on.

    Once I decided to set it while listening, to get the optimal sound, I had to drastically raise the arm and the angle looks very different but I can't argue with the sound. It's *quite* obviously better than how it was when I was calibrating it with an angle as opposed to using my ears as a barometer. Two opposite directions needed to get the results.

    I had no agenda and figured it'd be nice to get even better sound. Well, I did get better sound but in the end it was after I adjusted it on-the-fly that I got it which is something I had never done. Although I'm delighted with the end result, I'm nevertheless shocked at the differences.
     
    Last edited: Jun 20, 2017
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  4. snorker

    snorker Big Daddy

    Hey, as long as it sounds good. Must be nice to have the easily adjustable VTA!
     
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  5. deadcoldfish

    deadcoldfish Senior Member

    Location:
    Santa Rosa, CA
    Be sure to check VTF after the VTA change, just to be certain it's still set correctly.
     
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  6. Lenny

    Lenny Forum Resident

    Location:
    New York
    I have written often here that VTA/SRA should be set by the ear and not by the eye. As an unplanned experiment you've proven the wisdom of that. Nice that you have a VPI arm, so easy to adjust.

    We shouldn't take Michael Fremer and his microscope so seriously. Not only were different records cut at slightly different angles, but even the most careful setting by microscope can only get you into the neighborhood. I believe everyone who has written credibly on the subject has made the final determination by ear.

    Furthermore, it's not the stylus that will be correct at about 92 degrees. It's the rake. And the rake, not always parallel to the stylus, is sometimes extemely difficult to see even under a good microscope.
     
    Last edited: Jun 20, 2017
  7. amgradmd

    amgradmd Forum Resident

    Location:
    Richmond, VA
    OP: Which cart are you using?
     
  8. Strat-Mangler

    Strat-Mangler Personal Survival Daily Record-Breaker Thread Starter

    Location:
    Toronto
    I did as I was positive such a drastic change in height would be met with a very different VTF but it turns out the difference was -0.8mg. Not too big a difference but I'll eventually set it back to 2.2mg.
     
  9. The FRiNgE

    The FRiNgE Forum Resident

    Keep in mind your rake angle goes more negative a degree or two under the tracking force applied. The higher the tracking force, the more the cantilever deflects, the more negative the rake angle becomes.

    I understand the actual vertical angle of the groove varies from about 15 degrees to 0 degrees, according to the mastering engineer's practice, mostly older records are closer to 15 degrees... so a rake angle of 92 degrees (2 degrees positive from perpendicular) will be way off for older records, :crazy: the crazy world of vinyl!
     
    Last edited: Jun 20, 2017
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  10. Lenny

    Lenny Forum Resident

    Location:
    New York
    I don't know what you mean by "older records" but it was John Risch and a collaborator who did the research in the late '70s and confirmed the 92 degrees (or so) practice for the stereo era.
     
  11. missan

    missan Forum Resident

    Location:
    Stockholm
    SRA/VTA are set by VTF. The arm should be parallel to the platter.
     
  12. John Buchanan

    John Buchanan I'm just a headphone kind of fellow. Stax Sigma

    The playing "edge" of the diamond may not be parallel to its long axis. Not a problem with sphericals.
     
  13. GuildX700

    GuildX700 Forum Resident

    Location:
    USA
    I'm glad my Empire 698 is so easy to set up, set suspension to factory height, set cartridge/stylus to factory line on headshell, with typical thickness record set arm height to parallel with record.

    I've done very little fooling around as my cartridge installs have always passed all the Shure audio obstacle test tracks with flying colors, even the worst ones, and typical playback listening has never revealed issues from beginning to end of record sides. I guess some tables are more fussy than others, the more ability to adjust must lead to more poor set ups.
     
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  14. missan

    missan Forum Resident

    Location:
    Stockholm
    It doesn´t matter much. There still is about the same contact points.
     
  15. Bill Hart

    Bill Hart Forum Resident

    Location:
    Austin
    I've long wished for a remote controlled VTA on the fly mechanism, which has appeared on only two arms that I'm aware of. Why? Not for the sake of constantly fiddling ( I currently do not adjust VTA for each record), but because having the ability to make small changes while the record is playing makes it far easier to find the sweet spot- doing it manually requires that I stand off-axis and twirl a knob. Sure, I can hear the differences from the sidelines, but if I'm really doing the final tweak by ear, it would make sense (to me) to evaluate the changes from the actual listening position.
    I have just set up my turntable in the last week after moving from the East Coast to Texas. It took a fair amount of work, as did setting up the rest of the system. (I'm now in the 'dialing in' stage of the system, and after each session, the overall presentation improves).
    I set up hundreds of turntables when I was a teenager- I had worked in various stereo stores from the time I finished high school through the time I was in college. Back then, it seemed to be far more basic, cartridges did not cost what they do now, and there was less attention paid to things like VTA/SRA.
    When you have it really nailed, the system not only has both better bass and high frequencies, but the whole presentation seems clearer and more focused. I don't really know of any magic "tricks" to do that-- it is tedious.
    I also don't like having to mount 5 figure cartridges. I used set up people when I lived in NY- there were several who were really top notch, it was their business to do this day in and day out, so I knew I was getting an optimal set up. I could easily go from there, and fiddle with stylus pressure or VTA. When I got to Austin, there were no set up people. I called one dealer not far from Austin who said "Sure, bring it on in!" (I tried not to embarrass him when I told him that, aside from the fact that the table and arm, on plinth, weigh in at 231 lbs, not including the isolation base and stand, which is another 145 lbs, I far preferred set up in situ). The only thing I really needed was an easy way to do azimuth since the set up guys I've dealt with rely on the Fozgometer. So, I bought that from him and did it myself. When I got to VTA settings, I had my wife help. We used several records that I have long used for VTA and got it really dialed in.
    I did buy a couple of digital microscopes and experimented with rake angle using those, but I found it time consuming, hard to stay 'on point' with the microscope cranked up sufficiently to really see the stylus, and for some reason, though I could create images, I found the software for drawing and measuring angles almost impossible to work with. (I'm the first to admit that it may be my deficient computer skills at work here).
    I used to change VTA frequently record by record when I ran Lyra cartridges, which seemed to be acutely sensitive to small changes. The Airtights, which I have been using for 8 or 9 years?-- seem far less sensitive to minor VTA changes on a record by record basis. So, once I get it nailed for a "standard" (non-180 gram) record, I can adjust if necessary because the arm has a Vernier type gauge on the adjustment knob, on the arm support and on an external digital read out (if one uses the adjustable arm pod to change arm height, something I never do).
    I think you have to find a happy balance between getting it "right" and not driving yourself crazy. That balance probably varies from person to person. I have one friend who weighs each record, and has pre-set heights determined for each weight. I'm not going to make fun of him because his system was astounding good, incredible bass, very in the room mids and spectacular high frequencies without a trace of sibilance or "bite." That's just one method, if you are so inclined, but I'm pretty happy with a set it and forget it approach overall. I do think having the ability to easily adjust arm height while a record is playing ('on the fly') makes this setting process far easier to accomplish, even if you don't continue to change VTA on a record by record basis.
     
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  16. John Buchanan

    John Buchanan I'm just a headphone kind of fellow. Stax Sigma

    That's not correct. And it explains why setting SRA and VTA correctly is far more critical on a line contact stylus than a spherical.
     
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  17. John Buchanan

    John Buchanan I'm just a headphone kind of fellow. Stax Sigma

    Yes, altering the VTF will also alter the VTA/SRA, however that is not the correct way to ensure an optimum set up. Fine tuning requires optimising a lot of variables.
     
  18. missan

    missan Forum Resident

    Location:
    Stockholm
    The basic is arm parallel to the platter, correct VTF. With a quality arm and a good cartridge the azimuth will be OK.
    I find many suggested set up schemes to be in the subjective domain.
     
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  19. missan

    missan Forum Resident

    Location:
    Stockholm
    Why should it be more critical, and what explains it, do You mean? Of course the contact points are about the same.
     
  20. missan

    missan Forum Resident

    Location:
    Stockholm
    As I see it it is the correct way; arm parallel to the platter and using the correct VTF for the particular needle to fall inte place.
     
  21. John Buchanan

    John Buchanan I'm just a headphone kind of fellow. Stax Sigma

    Years of setting up tonearms in the past makes me skeptical of the "tonearm parallel to the record surface and fine tune the SRA/VTA with VTF" idea. This will lead to incorrect and suboptimal setting up. However, if you wish to do that, feel free. Your loss.
     
  22. missan

    missan Forum Resident

    Location:
    Stockholm
    Believe me, I don´t have any loss in this. Not having the arm parallel to the platter is always incorrect. If the pivot is higher the VTF will decrease, if the pivot is lower the VTF will increase; when applying stylus drag when playing.
     
  23. John Buchanan

    John Buchanan I'm just a headphone kind of fellow. Stax Sigma

    We'll just have to disagree on this.
     
  24. Lenny

    Lenny Forum Resident

    Location:
    New York
    Nonsense! SRA is a very misunderstood concept. Do some research. Setting the arm parallel to the record might get you the correct SRA, but it's highly unlikely. Your point about VTF is simply inapt. VTF may be set independently from SRA/VTA. SRA should be set by listening. A lot of people simply don't care, don't want to bother, can't hear the difference, or don't know how. But it's the only way to optimize vinyl playback. Otherwise you won't hear your set-up at its best, most especially with styli that have strong rakes.
     
    Last edited: Jun 21, 2017
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  25. Strat-Mangler

    Strat-Mangler Personal Survival Daily Record-Breaker Thread Starter

    Location:
    Toronto
    You didn't look at my profile? It's in tthre ; Dynavector 20X2L.
     
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