Hello all,
A bit of generic advice about high performance cartridges and tracking force ...
You've seen quite a bit of action on electronic stylus force gauges both here and on various other forums - gauges accurate to within .01 grams. You will find this level of precision to matter with cartridges at this level of resolution.
One thing to bear in mind is that you should measure tracking force at RECORD LEVEL.
Depending on the tonearm, you can have as much as a .3 gram difference between measuring at scale level and at record level. With the Schröders you'll be off by about .3 grams. With other arms you'll likely be off by less.
This has nothing to do with the absolute "goodness" of one arm over the other - we are after all tracking at record level and not 3/4" above the record.
Another thing to keep in mind is that every Shure gauge I've cross validated measures about .3 grams optimistic - with a 2.5 gram reading being in fact be closer to 2.2 grams. If have a Shure gauge, you can work around part of this error.
Position the Shure gauge so that 2 of its pads at its base overhang the record platter. This will lower the scale a slightly. This is a trick I picked up from Franks Schröder. Depending on your tonearm, you may not be able to cue your stylus down, but if you can, you'll get closer to an accurate reading. The scale will be slightly tilted, so take this into account as you line the pointer up in the mirrored area.
I've demonstrated the effect of a .05 gram change to several people on both a Dynavector XV-1s and a ZYX Universe (on both a Triplanar and Schröder Reference) - to their slack-jawed amazement.
Now, the first observation you'll correctly make is that a subtle change in tracking force affects the VTA/SRA as you load/unload the cartridge's suspension. We accounted for this by adjusting VTA/SRA both up and down. The effect you'll observe is far more gross and different in character than the result of a VTA/SRA change.
The most recent instance of this demonstration involved a Dynavector XV-1s, which I started out with a measured 1.92 gram tracking force on a Triplanar tonearm. Tracking was wonderful - contrary to numerous comments on this forum about the necessity of tracking as high as 2.5 grams.
The setup sounded a bit sluggish however - as if the turntable was running slow. I verified that the table was running on speed. The effect was that of Ricki Lee Jones' band sounding as if they were stuck in an all-night drive through Wyoming in a snow storm - with a white-knuckled bass player at the wheel. If you've ever driven through a Wyoming blizzard, you know how spent you'll feel the next day.
I lightened the force to 1.87, and BINGO! They sounded well rested and on tempo!
The above anecdote is one reason I tend to ignore comments about a cartridge's PRaT or its absence. Not to sound dismissive, but no post I've ever read on an analog setup has taken this aspect of setup into account.
People tend to think of tracking force in terms of mistracking, or in extreme instances from the perspective of maintaining the windings in the linear area of the cartridge's magnetic field. You never hear mention of under/over damping the resonant system.
On the subject of these posts on the Dyna XV-1s needing to track at 2.5 grams, I spoke with the US Dynavector distributor. He too is puzzled as to how these folks are setting up their arm and cartridge. Now, bear in mind that my above experience is limited to two tonearms at present - an 18 gram effective mass Schröder Reference, and a Triplanar (about 12 grams).
It's possible that some of the other arms in the 9.5 to 10.5 gram range behave differently. I would advise these individuals to re-visit their setup, and if you still find yourself needing to track at 2.5 grams, to increase your effective mass by adding a headshell weight - resetting the tracking force after the fact of course.
Cheers,
Thom @ Galibier
