I have spoken to JR at CAF, and I agree he is very smart and very knowledgeable on tonearms and cartridges; much more so than I. However, in a properly designed and implemented LT tonearm the friction force between stylus and vinyl has a vector that is constantly in a straight line with the junction between the arm wand and the guide rail (the pivot, if the thing could pivot). Furthermore the stylus is always tangent to the groove. (This is more certainly true of air bearing designs like the ET2. Some others like the Rabco permit teeny tiny arcs as the stylus traverses the LP.) Thus there can be no skating force. In addition, tell me what LT tonearm even has an AS device built on to it? Or is that what JR is selling?
HFNRR Test Record anti-skating tracks
I just bought a slightly used Benz Ruby 2 cartridge from a reliable source and installed it in my linear-tracking Eminent Technology ET-2 tonearm and SOTA Star Sapphire turntable. A classic analog front end. I set up the arm/cartridge very carefully, and this is my second go round with doing so with this 'table.
After leveling the turntable so the cartridge remains stationery in the blank area between tracks, in the middle of the HFNRR Test Record, I played Band 6, which contains a mono 300 Hz tone. The instructions say to listen for any difference between the channels to show whether the anti-skating is correctly set. Of course, with a linear-tracking turntable the only anti-skating adjustment consists of having the turntable perfectly level, which I also check with a bubble level.
On this band of the test LP, both channels sounded the same, but there was similar distortion on each side. The instructions for this band go on to say "If there is any hint of instability (distorted or buzzing sound) on one channel or the other then adjust the bias compensation accordingly." (Apparently "bias" is the British term for
"anti-skating."). So if there is distortion in both channels, what does that mean? I'm confident the anti-skating/turntable level is correctly set. On my old Shure Era III test record, the cartridge didn't do great on the trackability tests, but the only cartridge of mine that ever did was the Shure V-15 Type III (imagine that). The Ruby 2 could only pass the first two test levels before there would be some slight mistracking.
On conventional records the cartridge generally sounds fine, very similar to the Monster Cable Alpha Genesis 1000 that preceded it. Both cartridges seemed to mistrack one crescendo in "Meditation 2" from the Larajii Day of Radiance Ambient 3 LP, which sounds OK on an old Nakamichi cassette recording I made from this Japanese-pressed LP. Having made the cassette dub, I rarely played the LP. (FWIW, a different pressing of this unusual recording is on the TAS Super Disc list.)
I explained the HFNRR record results with the seller, who collects cartridges, and he suggested increasing the tracking force. I have it on 2 gm now; 2.2 gm is the upper limit for "recommended tracking force."
Would you agree to increase the VTF, or should I just ignore the test record result? I am inclined to try it, at least to see if the Ambient 3 track will play better. But it is laborious to adjust the VTF with the ET-2 arm.
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@benjie I've searched for the YouTube videos you mention and can't find them. Could you provide a link, please? I am inclined to agree with lewm, though, that antiskating with the ET-2 is covered by having the turntable perfectly level. FWIW, I did increase the VTF of my Ruby 2 to the max. recommended VTF of 2.2. I didn't hear any significant difference in going from 2 g to 2.2 g. When I've got nothing better to do, I may pull out my old Thorens with its Grace F9E cartridge and see how it tracks the Larajii LP. I made the cassette dub of this with the Talisman Alchemist IIb cartridge that the dealer originally installed on the ET-2 when I bought the turntable; the distortion isn't present on that recording, and my Nak cassette deck made very faithful recordings that would have shown such distortion if it were present. The only things different in my setup now (other than the cartridge change) is that I added a very thin felt mat to my SOTA and a damping trough to the ET-2. The latter was an addition recommended and made by Eminent Technology (Bruce Thigpen); it is filled with a silicon fluid provided with the trough. The manual claimed it had reduced flutter on one turntable down to .007%, and that their tests showed that wow and flutter is a product of the tonearm, not just the turntable. It says linear-tracking tonearms have lower wow and flutter than pivoted arms--one more reason to go with LT arms! |
I stand corrected on the use of the ET2 on a suspended TT like the Sota. That linear tonearms generate no skating force is not a matter of opinion. It's factual. However, probably there is no LT tonearm that is perfectly set up, so in the real world one may have tiny amounts of skating force but vanishingly low compared to any pivoted tonearm and not even correctable by any feasible AS device, because it would vary in vector direction as the arm traces the grooves, inner, outer, inner, outer-directed, etc. |
I used to distribute both products - there are no problems running ET2''s on Sotas. 1. There are no skating forces generated on the ET2 air bearing linear tracking arm, therefore your tests are redundant. 2. To check the level and that the air bearing is clear - First step - check the platter is dead level. Then - Set the counterweight so that the cartridge tracking is 0 ( arm is floating ) Make sure the arm does not drift either way - if it does it is not perfectly level. I also like to nudge the arm in both directions and check that the travel distance is the same in both directions. Once you are happy then reset the cartridge tracking weight. Please also note that depending on the compliance of your cartridge you can vary how the counterweight is set up - ie low weight further out on the beam or higher weight closer to the pivot. All the instructions are in the manual, if you don't have it they are on the Eminent Technology website. Contrary to many comments on this forum, the arm is very stable once set up.
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