SCOUT counter-wgt. problem--

[d.r.cook]

After several weeks, I've finally gotten a new(used) Shelter 501 cart intalled, and HAD it working pretty well. Was excited to use my Shure track force guage for the first time, setting tracking force at 2.5.

Ran a few albums, all seemed fine.

Then a couple days later, come back, play something and it's completely out of whack. Barely tracking at all, skipping, etc. And now, even I bring the counterweight all the way forward, it's not enough to move the force guage.

Clearly, something's way out of kilter, but I don't know what or how to find it (or how it HAPPENED) . . . I DO have an unusually tight set-up space, with heavy cables immediately behind . . . it's possible something got bumped, but hard to imagine that created this much havock.

Any suggestions? Theories?

Thanks,
Doug

[Gregory Earl]

You are sure you have the arm properly centered on the spike?

[mtodde]

You are sure you have the arm properly centered on the spike?


That's what I would check. It is pretty easy to put the tonearm on the spike off-center.

Once you have it set properly I'd back off the tracking force some. I had the best results between 1.8-2.1 grams with the 501 when I had my Scout.

[d.r.cook]

thanks i'll check--sounds like a good possib.!

doug

[d.r.cook]

Ok, that doesn't appear to be it. It FEELS like it's on the point, and the arm sits relatively level outside the rest . . . but still, when I set it for 2 grams on the guage (on 1 and setting the cart into the "X2" groove), even with the counterwgt all the way up, it doesn't budge the scale.

any further insight? The thing is, I'm all but positive it was set up correctly at a little over 2 previously, and it ran and sounded fine. I was also careful to get the pin on the counterwgt fairly tight before, so I don't know HOW it got out of whack like this.

I guess, unless there's other suggestions, I'll just give VPI a call on Monday.

thanks,
doug

[d.r.cook]

ah, haaaaa! it was the force gauge that had gotten out of joint . . . now tracking nicely at 2 . . . think i'll go a little lower.

doug

[dogpile]

ah, haaaaa! it was the force gauge that had gotten out of joint . . . now tracking nicely at 2 . . . think i'll go a little lower.

doug

Hey Doug. Glad you found the problem :righton: Setting up a T/T is fun yet frustrating at the same time :p

[mcow1]

ah, haaaaa! it was the force gauge that had gotten out of joint . . . now tracking nicely at 2 . . . think i'll go a little lower.

doug

:thumbsup: Glad you found the problem.

[Gregory Earl]

Heh. Alright Doug:goodie: . Now let's spin some tunes. Shall we?

[marcb]

Glad you figured out the problem. :righton: FWIW, you may also want to keep a couple of other things in mind.

One, the Shure gauge doesn't measure VTF at record level, but rather a little higher. Consequently, even if your guage is accurate at weighing mass (and some of the Shures aren't), the gauge will probably indicate a weight of about 2/10ths of a gram heavier than actual tracking force at record level.

Two, FWIW, the Shelter 501 is a fairly low compliance cart (9x10-6) and the JMW9 is a fairly low mass arm (7.9 grams). In essence that means that Shelter has a fairly stiff cantilever and with a light tonearm such as the JWM9, the resonance frequency is around 15hz rather than in the optimal range of 8-11hz because the JWM9 doesn't put enough mass onto it at proper tracking force.

Assuming you are using the standard JWM9 arm, you may want to try adding some weight to the tonearm in order to get proper resonance matching with the Shelter 501. Ideally you should probably add quite a bit of weight in order to get a resonant frequency of about 10hz. But you can probably get it down to around 12hz by adding 3-6 grams of weight to the headshell.