Discuss The Viv Lab Rigid Arm

@atmasphere    The hardness of the metal in the bearing is not the only issue.  The fineness of the machining is fundamental.

Another one I have thought about is my Simon Yorke Aeroarm.  This is a parallel tracking design, very lightweight with a distance from pivot centre to stylus of about 3 inches.  The arm has a round aperture sliding along a steel bar separated by an air bearing.  The clearance of the air bearing is 5mu centimetres.  The air pressure is 1.4 bar, held steady by a hospital grade compressor and control valving.  I have wondered what movement this might allow (if any) and noted such is likely to be in line with the arm and therefore the groove so not affecting azimuth.  I have never heard distortion of any kind on this rig which is my forever player and sounds simply wonderful with low-mass cartridges.

The hardness of the metal in the bearing is not the only issue. The fineness of the machining is fundamental.

@clearthinker 

Yes. The bearings in the Triplanar are tiny.

The problem you have with any arm with a short arm section is any record warp will be audible as a speed variation and will affect the bass impact since the tracking force changes with warp and bass modulation. To get around that the bearing must be in the plane of the LP. Think about two people carrying a couch upstairs. Who is carrying the most weight?

@mijostyn   The tracking error of the Viv varies as the effective length chosen. I f I wanted the Viv I would instinctively go for the 9 inch version, although quite a number of commentators have said they prefer the 7 inch (6 inch anyone?).  But whichever you choose I rather doubt the tracking error would be as gross as the 5 degrees you postulate.  Nevertheless I am curious that a quite a number of listeners say they cannot hear the resultant distortion on the 7 inch Viv.  I think it would be interesting to play sine waves on that and a conventional 9 inch arm using a line contact or similarly radical stylus and see if there is audible distortion.  It may be easier to perceive it on a steady state signal than with music.

To more realistically mimic the tracking geometry of the Viv, you would also have set your cartridge to the correct underhang.  Might actually be a fun experiment...

@mijostyn   Warped records are a menace.  I have very few as I have rejected them unless the programme is very desirable and the disc very rare.  But in fact the Aeroarm plays severely warped records better than bigger and heavier arms.  Typically a bad warp throws the pickup into the air, particularly on 45 or 78 rpm.  Because its moving mass is around a quarter of a light 9 inch arm and the moment of inertia much less because the effective length is only one third, every warped record I have stays in contact with the record.  I concede it doesn't sound very nice, but it does keep playing!  Not really a virtue I am inclined to crow about.

As to carrying a couch upstairs, indeed.  Although that is much less of a strain than a heavy large speaker, such as my ML CLX Anniversaries that I recently had re-furbished and where at 72 years of age I had to help the carrier at the low end; we had one corner each.  The guy at the high end had a much easier time.  There was no room on the stair to fit more than two at the bottom.