HFNRR Test Record anti-skating tracks

@dover 

Thanks for the reminders about the manual's setup instructions.  I reviewed them and just checked the tonearm's behavior on a small mirror, and it was motionless.   I also noticed the azimuth was a hair off.  After correcting the azimuth, the cartridge finally saled through the lowest-level anti-skating torture test on the HFNRR LP without distortion, although there was distortion on the hotter-recorded examples of the same 300 Hz test tone.  As before, the distortion was even on both channels.  After correcting the azimuth, the cartridge could also track a level higher on the tracking tests of the Shure audio obstacle course era III  test LP.  This suggests that slight mistracking on these test records doesn't necessarily ruin their grooves permanently.  (I used LAST LP preservative on these LPs.)

I compared the LP of Pat Metheny's Still Life (talking) with the CD, using my Cambridge Audio CXU as a transport and the Denafrips Ares II DAC.  I could distinguish no differences between the two, using my Sennheiser 650 headphones and Li'l Headroom Plus headphone amp.  The last time I tried this test, probably with my Monster Cable Alpha Genesis 1000 cartridge and the Cambridge CXU, I thought the LP had more articulate bass on "Last Train Home."  The CXU's DAC is brighter and louder than the other two sources.

@drmuso 

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.

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.

@lewm 

Regarding your point (3) above, as you may have read in this thread about tonearms for the SOTA, a former SOTA rep said that the ET-2 was used in their reference system, and they had no problem with the combination.

@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 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?

J.R. has a few seminars on You Tube on the subject  and speaks of how important it is to have proper anti-skate on linear tonearms. He also speaks on the pitfalls of increasing VTA  beyond the midpoint of a cartridge's recommended range. J.R. Is one of the most knowledgeable experts in this field. You should take some time to listen to what he has to say on the subject.

Given the results, I wouldn't hesitate to increase VTF to the top of the manufacturer's range.

Guys, it’s a linear tracking tonearm (the ET2). A properly set up LT tonearm generates no skating force. Zero. And anyway as regards the Foz; it’s for azimuth adjustment, is it not?

drmuso OP

I would suggest that you look into a tool made by Wally Tools...The WallySkater... for setting up anti-skate on your turntable. The tool has the ability to be used with linear tracking tonearms. There are many videos on the subject of Anti-Skate at the website and on why test records are not the best choice for setting anti-skate. There is a wealth of information at the website. If you have any questions, J.R. would be very happy to discuss any setup issues you may have. His knowledge on tonearm and cartridge setup is amazing.

  The Fozgometer is used for setting up Azimuth for your cartridge.

Thank you both for your prompt responses.

@lewm Your (1)--isn’t that cartridge overhang? I did check that with the cartridge alignment tool provided with the ET-2.

(2) You are correct about the type of level I used, so I just rechecked it with an 8" linear level, and it looks good in both planes.

(3) The ET-2 has a horizontal mass of 30 g, vertical mass of 7 g. I guess as the arm traverses the platter there would be some slight effect, but the benefit of the vacuum hold-down of the platter (and benefits of the turntable suspension) is probably more audible and worthwhile, in my estimation. Most mildly warped records (talk about "relative motion between the stylus and the platter"!) can be completely flattened, and such warps probably have more of an effect than the turntable suspension. The hold-down also reduces resonances from the vinyl. Physics is not my strongest subject, so I’ll admit to some handicap in evaluating such things. Generally, playback of music has always sounded great, and I haven’t noticed a systematic decrease in audio quality at certain points of most records, which I imagine would be the issue if there were serious effects from the interaction of the linear arm and the SOTA suspension.  Also, the HFNRR Test Record has the same tracking tests at disparate points on the record, and I can check that the distortion is the same with all of them.

@stringreen Thanks for your offer, but I’m quite far from AZ. But also curious what a Fozgometer is/does.

Fozgometer to do what correctly? 

Get a Fozometer to do it correctly.   If you're near Scottsdale, Az, I'll lend you mine

I apologize in advance for some of my ideas based on your post, because you are obviously both knowledgeable and experienced in using this particular combo of TT and tonearm, but here goes:

(1) I am sure you know this, but there is one thing more to setting up any cartridge on any linear tracker that you did not mention, which is that the stylus tip has to sit exactly on the radius of the LP such that the arm wand is perpendicular to the radius.  Else you will have wow (which could be a source of the distortion you hear). Did you take care to get that right? (Most likely you did and just did not mention it.)

(2) Bubble levels are nice but not the absolute most accurate way to check that the platter is level. Better is a linear carpenter's level, used to check level across the platter in two planes at a 90 degree angle to each other. (I am assuming you used one of those small round levels that has a circle in which to center the bubble. I use one  like that only to "ballpark" level.)

(3) Is it really the best idea to have an air bearing tonearm on a spring-suspended TT? Any relative motion between the stylus and the platter is a no-no, and in my imagination I am thinking that could happen with a passive air bearing arm like the ET2 on a spring loaded TT, and maybe that is why you are not getting optimal tracking.  I personally don't like the idea of increasing VTF just to improve tracking when you are already near the upper end of the range recommended by the manufacturer, but I would not say it's "wrong", especially if it works.

(4) "Distortion in both channels" probably has nothing to do with skating in this case.  Also the HFNRR instructions on how to attain "correct" anti-skating (which does not exist) do depend on the acuity of the listener, probably not very accurate which probably doesn't matter.  Another way to use their mono AS band would be to make one channel 180 degrees out of phase with the other (by for example swapping wires between hot and ground at one speaker.)  Thus the signal in one channel would cancel the other when AS is set optimally, at least for that frequency at that segment of the LP.