Tightness Of ARO Stub

Posted by: Mark Dunn on 06 August 2000


I recently removed the ARO from my LP12 to give the cartridge a sprucing up and I noticed that the stub on which the main counterweight sits was loose. Apart from the fact that you can't adjust the tracking weight with this condition (the stub and C/W turn as a unit with not relative movement), it's probably prone to resonate too.

The stub is held to the main bearing cup with a small screw that's accessed through the centre of the stub and thus it's easy to tighten. My question is, how tight? There's a rubber grommet between the bearing cup and the stub, so it's obviously not meant to be 'Linn tight'. I've tried 'a bit more than pinched up' which produced a prominent bass resonance, - so I backed off a smidgeon which significantly reduce the issue.

I'd appreciate input from anyone with experience of this (those nice Naim folks, perhaps?) as I would imagine that this is a well known effect. My front end is Armageddon/LP12/ARO (with heavy C/W)/Dynavector DRT-XV1. Thanks!

Best Regards,
Mark Dunnn

Posted on: 08 August 2000 by Dev B

The stub can be considered to be an integral part of the arm tube and should be tight with no movement all, obviously overtightening can cause stress on the main cup, but it is quite unlike the bearing pillar screw and the cartridge screws which must only be done up 'just so' so that you feel no resistance.

The change in bass may be becasue your adjustments to the stub have allowed the counterweight to be moved forward, closer to the tonearm pivot. This tends to change the character of the bass and midbass considerably.



PS. How are you getting on with the XV-1?

Posted on: 08 August 2000 by Mark Dunn
Hi Dev:

Thanks for the input regarding the ARO's stub, - I'll take a second look.

>PS. How are you getting on with the XV-1?<

The XV-1 is utterly superb! It's *SO* far ahead of anything else I've heard that comparisons are pretty meaningless. If you haven't heard one yet, it's definitely worth the effort.

Best Regards,
Mark DunnĂ

Posted on: 10 August 2000 by Mark Dunn
Hi Mark:

Thanks for the input. I've now tightened it just a touch more than is necessary to prevent the stub turning with the counterweight when setting the tracking force and all is (very) well.

By the by, anyone at Naim tried the Dynavector XV-1? It's very symbiotic with a fully Naimed LP12! All I need now is a Prefix/Hi-Cap so I can have a fully- fully Naimed LP12.

Best Regards,
Mark Dunn