VPI JMW arms
Cemil Gandur -- Thu, 05/22/2008 - 11:36
I'm using that arm on the Super Scoutmaster, first the 9" and now the 10.5" version. The problem I am having is that the arm mistracks badly on some audiophile records. I've tested it using test discs, and it basically only makes the first out of four test tracks (in order of severity).
I assume that most of it is bias related, since that's what the test tracks are for, and when I pull a bit on the bias wire of the JMW, it stops mistracking.
The problem is that VPI doesn't believe in bias, and althought they supply a crude wire and weight thing, they seem to imply that the JMW doesn't need any. There are not enough rubber rings provided with the 10.5" arm to bias it to the point where it can track the second test track.
VPI suggests to increase the tracking weight, but I'm already at 2.2 grms with my Dyna XV1S, which is towards the end of max.
Any suggestions? Is tracking only a function of weight and bias or is there something else that I have overlooked? I'm nitpicking a bit as the issue is only obvious on some recordings, but still, it is annoying to have it. I don't remember any such issues with my old Linn.
Thanks for any help.
Hi there, one clockwise twist of the connector solved that problem in my 12.6, you can try either direction depending what channel is the mistracking, it now makes 3 tracks of that test record, I believe the fourth is pretty close to impossible. Make sure to recheck azimuth after, cheers marco
Connector?
Sorry, the thin wires that exit the armtube end in a connector that locks into the junction box, you carefully unlock and twist it one way or another before locking it again. Doing so you change the bias force, but not in fine increments, because you have to twist the connector 360° to lock it again. This will also affect azimuth, so make sure to check it again also. Sorry for the bad english, hope it's clear anyway.
Very helpful. Thanks!
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