SMEV set up problem....help needed

Nsgarch,
please bear in mind with all this beautiful theory, and also Dertonarm, that:
1) At least with the SME V the pivot post can be clamped within a "range" (tilted ~ 1-2 deg. either to one or the other side!) thereby changing azimuth slightly, quite often un-noticed when changing VTA / SRA.
2) If in the case of a record clamp like e.g. VPI (rubber washer), SME (alu washer), yet another ~ 1-2 deg (vinyl level) is the case mostly toward the last band of the record, since the record centre is slightly elevated for the clamp to work as intended.
3) If a record is not completely flat (and which one is?) yet again the azimuth is changed by the vinyl, offering a different "level" surface constantly during each revolution.

I guess it is like with most things, try and get things set-up well --- yet try NOT to get too anal about it, lest you may not listen to music any more but to azimuth, VTA, SRA, VTF, etc. etc.
Greetings,
Axel

Hi Axel, the three items you mention are all factors, but I take question the degree (literally and figuratively!) of their impact.

1.) Less than a half degree on the tonearm azimuth, and easily dialed in with a small spirit level across the headshell assuming the platter is leveled first; and assuming the stylus is true to begin with.
2.) Again, less than half a degree -- even on the worst warped records. More than a half degree and tracking begins to deteriorate, possibly the tonearm will fly free of the record! An eighth inch deflection (or warp) at the outside edge of a record is about one degree and nearly untrackable (depending how steep the bump.)
3.) Again, a negligable deviation.

It's not easy to get the Stylus Rake Angle perfect either; there is no standard, and records (especially these days) come in different thicknesses. And not everyone has a TriPlanar, Graham, or some other arm with on-the-fly micrometer adjustment. HOWEVER, it's very important to at least get in the ballpark. And to do that, you have to know where your arm is set when the stylus on YOUR cartridge is perfectly vertical. Thus my method for determining that condition.

Nsgarch,
let's agree to disagree here.
If the avg. spirit level is toward the one or the other side touching the demarcation line THAT is NOT 1/2 degree!
I work with that stuff so let's say 1 deg. plus to one and 1 deg plus to the other side, i.e. 2 deg from one extreme to the other. I will go with 1 deg. on average, yet the rage is 2 deg.
Now getting anal with microscopes, 1/2 deg. would be *much more* noticeable than that spirit bubble being but only very slightly out to the on or the other side, at least that's my learning.
Greetings,
Axel

Axel,
I use a miniature calibrated bubble level -- mainly because it sits on top of the headshell more securely. But I could use a small spirit level, like the one van den Hul supplies with his cartridges. Either way, I could do so with a much higher degree of accuracy than you imagine possible ;-) As long as the instrument has been calibrated to a reference, it's all in the eye of the "technician".

BTW, two other ways to check and set azimuth accurately are:
1.) The 'null' method: playing an out-of-phase white noise groove with the preamp set to "mono".
2.) The mirror method: viewing the stylus with a small scope (from in front of the cartridge) as it rests on a first surface mirror and adjusting for a perfect hourglass shape; similar to the SRA calibration technique.
3.) Another method for dialing in the azimuth (similar to the 'null' method, is to use an ocilloscope.

Frankly, I like these three methods better than the leveling technique just because they take into account that the diamond itself may not be perfectly "true" in relationship to the cartridge body.

If one is using any kind of cartridge with a line-contact or microridge stylus, this degree of setup accuracy is really essential rather than 'anal'; and the results prove it. On the other hand, there are many fine cartridges available with elliptical and even spherical styli, which are more tolerant of less than perfect setup.

Neil
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