Shelter 90X Tracking Force


What is the best for the 90X. I a full blown LP-12/Ittok LV II arm. I am currenlty tracking at 1.9 gm based on my dealer recommendation.
xagwell

Showing 5 responses by thom_at_galibier_design

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
Hi Xagwell,

There's a lot to be said about set and forget. You get to focus on the music and that's not a bad thing at all ...

If you get bored (and only if you get bored), you of course can obtain a more precise gauge. I would not mess around if I had "only" a Shure gauge because your results would not be repeatable. The subtle changes in pacing can be quite remarkable with fine cartridges like your 90x.

I've had quite a few questions as of late about the "Class B" rating. I don't want to hijack this thread to discuss this, but it's been on my mind to expand on the my manufacturer's comments (published in Stereophile and posted on my Rants page).

Stereophile limits manufacturers to 750 words. Between not wanting to be ungracious and the word count limitation, I left a lot out. My first draft was over 2,000 words. As Mark Twain once wrote "I would have written you a shorter letter, but I didn't have the time". It was painful to snip all of my comments. In the next week or so, I plan on publishing my thoughts on my Rants page.

Cheers,
Thom @ Galibier
Good trick, John / Doug ...

Can you imagine how much fun it is to exhibit an analog rig at CES, with the doors open to the morning air in Las Vegas in January?

It sure catches my attention.

Cheers,
Thom @ Galibier
Hi Larry,

The Durascale 100 made by MyWeigh has given me repeatable readings. You can Google for their website and link to online retailers.

The only calibrating tool I have for these is the manufacturer supplied weight.

Calibrating weights from two different MyWeigh models differed by some .08 grams for a 100 gram weight - a .08 percent consistency of the calibration "tool".

This weight variance seems good enough for our purposes, since we're concerned with repeatability more than we are with an absolute number. I don't think you care that my 1.87 is your 1.88 - especially since you need to work around the temperature in your room to establish your own norm.

Likely, a better calibrated 100 gram weight is readily available if this causes lost sleep.

The real challenge lies in measuring at record level, and here the price jumps considerably for a pre-configured solution. I'm working on having parts made for a small fitting to use with these Durascale 100's but will likely take a month or so before I get around to this.

The reason I'm using the Durascale 100 as opposed to the 50 is because the acrylic fitting comes in at about 75 grams and I need to be able to "Tare" this amount out.

Our mutual buddy Dmailer, builds up a platform to get the measuring surface of his scale to record level - without using a step-down fitting on the weighing surface.

This solution can likely work quite well with your Teres since your headshell is out in space. Pile stuff up under the scale by resting it on your tt shelf instead of on your platter. This could get a bit tricky with some 'tables. You'd definitely want this "stuff" you rest the scale on to be stable.

Cheers,
Thom @ Galibier
No offense taken, Speedy One ...

I find myself in the difficult situation of trying to give anecdotal evidence while at the same time not coming off as being self promoting or condescending of other manufacturers.

Of course, I can speak only of arms I have extensive experience with, and in the last 24 months, I've lived with ... well, you know...

My 9 month stint with a Graham 2.2 in 2003-2004 was too long ago to be relevant to any current discussion. Since then, I've changed (and I'd like to think improved) my electronics and my speakers.

Part of the problem I had at the time was that my electronics and speakers had the same system bias as my Graham 2.2 did. They were all oriented toward a thin sound which tended to exaggerate "detail" at the expense of body.

I had only my turntable to balance this out. I didn't, I would likely have ripped many of these components out of my system a lot sooner.

Please don't misconstrue this as my being a bass fanatic. I can very happily live with speakers that drop like a stone below 60Hz, but I don't like components that play a slight of hand game with detail.

I'd like to re-visit the 2.2 as well as to play with the Phantom on a clean slate. Of course, this would still be in the context of a single system, but at least it would be a different system, and might better help me to triangulate in on the truth.

The Summer is a good time for this type of exercise, as folks slow down with things audio and I have time to play ... to the extent that I'm not out on the cliffs.

Gosh! What happens if I love the Phantom and start selling it. I'll be back in the same boat again (sigh).

Cheers,
Thom @ Galibier