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VPI JMW9 Tonearm setup questions

I just bought a VPI Aries Scout via mailorder, and am in the process of assembling it. I have some familiarity with setting up and adjusting cartridges and tonearms, BUT, I must admit that I am not familiar with unipivot tonearms.

I have no local dealer that has any VPI turntable set up, so I have not actually seen a JMW tonearm setup. I purchased the Scout based on the very positive comments here on Audiogon and elsewhere.

So, my question is really a basic one. The JMW9 Manual at page 4 states simply to "Place the arm tube assembly on the lower bearing." When I do that, the entire arm is balancing on the sharp pivot point of the lower bearing, but it is otherwise not secure in any respect.

Because the manual has no drawings or pictures showing what parts are to go where, I've been scratching my head wondering if I am missing a part of the bearing assembly that might slide over the sharp pivot point and takes up the space inside the cavity of the upper bearing housing. In fact, the nomenclature of "bearing housing" implies that this cavity is supposed to "house" a bearing, and there is nothing in there except the sharp pivot point.

Am I missing something here? Or is the tonearm supposed to float and wobble around touching absolutely nothing except the pivot point.

I hope this makes sense. Thanks for any guidance you can offer.

Coffee_nudge
Tad
coffee_nudge
coffee_nudge OP
120 posts
 
ANOTHER remedial question:

The manual also indicated that tonearm height (VTA) can be adjusted with the "knurled knob" beneath the pivot. However, when I turn the know, it does not appear to do anything except move the knob itself up and down the threaded shaft.

The manual is not very helpful for a relative "newbie" like me. So what am I supposed to do with this knob, other than twirl it up and down the threaded shaft (no obscene comments please). Keep in mind this is the JMW9 -- I understand the 10 and 12 are somewhat different in the VTA adjustment mechanism.

I apologize for these elementary questions, and appreciate any and all help with this new (to me) tonearm design.
slipknot1
1,423 posts
 
There should also be a small set screw that needs to be lossened. The whole assembly can be adjusted up or down, depending on the knob's position. Loosen the knob, pull the assembly up, retighten the knob. do this in small increments.
docjr8156
34 posts
 
Hi,

First you have to set the knurled knob at the lowest position in the shaft. Use the supplied wrench (bigger one) to loosen the "set-screws" in the base of the arm. You can locate 2 holes where these screws are, one directly to the back of the arm assembly and the other one 90 degrees from that on the right side if you are facing the table. Once you loosen these set screws, if you move the knurled knobs, you will notice that the height of the threaded shaft changes. This is the VTA adjustement for the Scout. Start by making sure that the LP in the platter is parallel to the arm. Use the arm tube to parallel and not the headshell. Also, make sure that the headshell of the cartridge is parallel to the LP surface. Using the supplied "tractor" you can easily align the cartridge bth horizontally and vertically. After all these settings, you'll have your "starting point". All adjustments, especially the VTA" can be fine tune by ear. Hope this helps.
coffee_nudge OP
120 posts
 
Okay. I am making progress here....got the tonearm and cartridge basically set up. I was running through the paces of the Hi Fi News Test LP, and ran into a brick wall when dealing with (you guessed it!) anti-skate. I realize this is a somewhat "controversial" issue with HW/VPI/JMWs.

I can get the cartridge to handle Track 6 (300hz +12db). But then I get a buzz from the right channel on Track 7 (300hz +14 db) and the arm just loses tracking on Track 8 (+16db). I did not even try Track 9 (+18db).

The results described above were achieved using the twist of the wire method suggested by VPI, with two full counterclockwise twists to increase anti-skate. I am reluctant to twist it any further, as I do not want to cause any damage to the wires.

Is this normal anti-skating performance for a JMW arm, or is there some method I should try, or is something else out of whack.

Thanks to all who have helped so far. Keep the info coming (please).

Tad
jmcgrogan2's avatar
jmcgrogan2
6,346 posts
 
Slipknot1, that's my mistake then. I assumed (I know, I know), since my JMW 10.5 arm has damping oil in the cup which houses the point, I assumed the JMW 9 arm was a similar design, only shorter. Sorry if this caused any confusion.

Regards,
John
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