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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.

drmuso

Showing 5 responses by lewm

lewm
13,467 posts
 

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
13,467 posts
 

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?

lewm
13,467 posts
 

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?

lewm
13,467 posts
 

Fozgometer to do what correctly? 

lewm
13,467 posts
 

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.

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