Linn LVX mounting position question

[kptv200]

Hi,
I'm currently building a modified L75, to date i have reduced the top-plate by removing the tonearm mounting hole section and welded a new edge to create a 13" x 13" square top-plate. I did this for mounting a Linn LVX(not the best i know, but on a budget!) straight on to a bespoke solid plinth, reason being i wanted to avoid any issues with the VTA and create a neater mounting with the Linn collar. Now having downloaded a mounting template which was slightly out of scale, i can see the spindle to post distance on my project is going to cause concern, due to the required centered hole and eventual collar position clashing with the side of the modified top-plate. I have checked the distance with a beam compass and the mounting collar is going to foul with the plate edge, and i'm now wondering how to over come this problem. Now the question....is it possible i could move the mounting around in the required spindle to post distance radius arc - see attached photo.
Would this work or create issues with overhang? Your advise would be greatly appreciated.

Kevin
SE London

[AJ]

As long as your spindle to pivot distance stays the same anywhere within that arc is ok, BUT just check where

You cartridge tracks, you don't want it over the motor it will pick up hum from it,

Mounting distance is 211mm, linn collar is 60mm wide, half that is 30mm to Center,  211 - 30 = 181mm

To EDGE of mounting collar , if you use a ruler you can sight along your arc @ 181mm to see where it looks best

When your happy with position then do accurate measure of 211mm mounting distance,

Overhang is 18mm and set with cartridge in head shell after arm fitted

Sounds tricky but it's not, take your time and if in doubt ask  

I like the shape of your top plate,  very nice  

Linn arm is not bad ( i use one ) were not all loaded eh  


Foot note,mine is the lvx basik plus but I think the collar is the same  ie 60mm

[wer]

I do not know the Linn mounting collar, but is there any problem shaving off a 4 or 5mm flat from the side?

[tonyw]

Yes, the proportions of your modified top-plate do look good.

If the 60dia Linn base forces you to locate the arm too far forward for visual satisfaction (or hum avoidance), and you don't want to modify it, you could try getting a smaller threaded base made. This could either thread directly into a timber plinth, or clamp in place with a nut below.

From a quick web search it looks as though the shaft diameter of Linn arms might be nominally 25mm, so you should be able to get a base of no larger than 40dia to work, if that's what you need.

Tony

[Chris65]

I imagine you would not have to move the tonearm mounting much further forward on that arc to clear your top-plate. The headshell would still be well away from the motor, see the Gallery for some idea, your cut-down top-plate must be very similar in size to a PTP3/4.

[kptv200]

thanks all for your thoughts and suggestions, i am relieved the post and collar will still be fine within the Spindle to post arc. I will make a protractor that will include the 6mm collar holes and 25mm post hole, and work out the best location in relation to the top plate edge.

Kevin.

[kptv200]

Positioned the tonearm mount ...checked and double checked the post centre to spindle. All good. ..but the template I downloaded suggests a pillar shaft hole of 25mm....not the case, it needs 30mm!! Now got to centre a bigger hole...grrr!

[kptv200]

ok.. now centered an enlarged mount hole and about to set up a test run on the turntable before veneering the solid plinth. Question: the ground wire at the din plug end of the tonearm cable - is it grounded on the top plate? Oh and the tonearm is mounted on the plinth and not on the top-plate if that makes a difference.

[colin]

Hi Kevin
The flying ground lead at the din plug end is for connecting to a sprung subchassis eg Linn or Thorens.  It is not needed on  your Lenco - can be left disconnected, the arm is grounded to the tt chassis via the collar.  Just connect the flying lead at the phono plug end to the preamp/main amp ground post.
hth
 

[kptv200]

Hi Colin,
thxs for your reply, i've trimmed the tt chassis down, and the arm is now mounted upon the mdf/ply plinth, will this make a difference ie no contact with the metal tt chassis? will the 'flying ground lead' need to be extended and connected to the tt chassis? if so i guess a separate grounding nut n bolt from the mains/motor grounding?

[rfgumby]

You'll want one common point where all the grounds on the TT are connected to.  Typically this is referred to as a "star ground".  If there's a top plate, that's where I'd connect any grounds which you require- and all on the same post, not at different spots on the top plate, that would create multiple ground points, which is often really a bad idea with tiny signals such as these.

[kptv200]

thanks for the tip, i'll be making a 'star' on the tt chassis. Looking forward to my test run prior to the plinth veneering.

Kevin