The upper limit tracking weight should not be exceeded. You should not use it to set VTA/SRA
Most cartridges(but not all) are designed such that the top of the cartridge, that mates to the arm, should be parallel to the playing surface - this almost always ensures the SRA is correct or within acceptable tolerances
Some cartridges do respond better with a "Tail-up" or "Tail down" alignment, but that is accomplished using the VTA adjustment feature of the arm (if it has one) - not the cartridge tracking force
The following is from Soundsmith on VTA/SRA
So as you can see - the stylus angle should NOT be at 90 degrees.Firstly, let me explain a bit about VTA vs. SRA. This is a complex subject, one that is one of the most misunderstood aspects of cartridge design, manufacturing and alignment.
VTA is a term that describes the CANTILEVER tracking angle. Soundsmith uses cantilevers with VARIED designs of VTA. The universe of cartridges have historically been made with varied cantilever tracking angles over the many years, from as low as 15 degrees to as high as 30 or more. The angle of the cantilever is of little value, as it describes only the design of a particular cartridges use of a particular cantilever/stylus design. What is finally important is always the SRA, or Stylus Rake Angle. That must always be 2 degrees, raked back towards the direction of the incoming groove in the record – that matches the way most all records are made.
Soundsmith uses varied cantilevers, with varied VTA’s; these can change slightly from unit to unit as there is often variation in the mounting of the diamond as well as the faceting of the diamond. Many cartridge manufacturers do not take this into account carefully, and as a result, the resultant SRA can vary badly from unit to unit. Michael Fremer did an expose’ some time ago showing a very expensive NEW cartridge where the VTA was correct, but the SRA was not “just a bit off”, - in fact, it was not even close to being -2 degrees, but was PLUS 10 degrees. He posted a picture of it.
Recently the use of USB microscopes has brought a plethora of “experts” who believe they are viewing the SRA correctly. Often, they are fooled by the optics, an issue also complicated by the fact that by not realizing that by viewing the “shank” of the diamond they are not viewing the actual facet angle which traces the groove walls. This facet edge position VARIES from diamond to diamond within a single diamond stylus design as the shaft of the diamond is not always held perfectly in the tool that is used to hold it while the facets are being made. It can vary as much as +/- 4 degrees easily – WITHOUT the ability of being easily observed.
So, while folks believe that they obtaining correct SRA by viewing either the edge facet itself, the cantilever VTA or the diamond shaft, they can still be very far off. Knowing the VTA of a particular cantilever/diamond design is therefore of little value. Also of extreme importance is the fact that a STATIC view of SRA - versus how the cantilever moves UP when the record is playing, offers additional degrees of ERROR when using a USB microscope to determine proper SRA.
An interesting case is the diamond we use in many of our models, including the Sussurro. Many who view that diamond with optical aids are shocked to see that it is raked back by what appears to be as much as 20 degrees, and have questioned Soundsmith’s ability to mount a stylus.
This particular diamond we use in several of our designs has a “HIDDEN” facet at the bottom, thus returning the SRA to 2 degrees raked inward. A discussion of our stylus in this regard, and the explanation, can be found here:
http://www.audioasylum.com/cgi/t.mpl?f=vinyl&m=927659
The most important thing to know when setting up ANY cartridge is that if it lucky enough to have been made correctly, that when the cartridge is mounted, the tone arm should be parallel with the surface of the record. SRA adjustments up and down from there can be made, and there are many ways to do this by ear, with advice coming from many sources – sometimes with opposing views - all posted on the web.
Soundsmith cartridges differ from others in this respect; since we well recognize the many extreme variables in mounting, manufacturing and attaching diamonds and cantilevers – as well as the SUSPENSION differences from cartridge to cartridge in ALL types of cartridges, we make every effort to adjust each of our cartridges individually to the variable nature of the true SRA of each cantilever/stylus assembly.
Therefore, we assume that people who know about mounting and aligning cartridges know that one always starts with the tone arm parallel to the record, and adjusts up or down from there to listening preference.
It may sound better, but you may be doing damage to the stylus or your albums
Regards