New 55,000 Euro tonearm

@mikelavigne 

i’m not good at ’why’. in my mind i can connect the dots and reason that a field coil assisted uni-pivot bearing has an advantage of a powered magnetic field with zero mass assisting the bearing performance.

Mike, it is simply a unipvot bearing.

The field coil is used for stabilisation - stop the wobble.

The advantage of the field coil over a magnetic field is that the field coil uses a constant current source, From their site -

The field coil, the special formed counter magnet and the CCS regulator provide the base for the stabilized unipivot bearing.
The field coil also functions as a sensor for unwanted torsional movements. The constant currency source compensates field variations in real time and keeps the magnetic field stable.

It's designed to take advantage of the unipivot, which has low bearing stiction, but address the inherent instability of an undamped unipivot. If I recall correctly Martin Colloms tested and reported that the Naim Aro had the lowest bearing stiction of any arm he had measured.

Other methods of stabilisation include having a centre of gravity below the pivot ( not ideal on warped records ),fluid damping ( examples Mayware/Moerch/Kuzma ) and magnetic fields.

@dover 

i've owned a few unipivots; many years ago (late 90's, into 2001) i owned a couple of Graham arms; the 1.5 and the 1.5tc. they were a bit wobbly. never owned a Phantom or Graham after that.

i've owned 2 Durand Telos unipivots, and a Durand Kairos uni-pivot; both designs which use a side azimuth bridge to steady it. there was an art to setting up these particular arms in terms of degrees of tightness of the bridge and the whole balance. the Sapphire Telos was an amazing arm, still is. one of the very best arms i've owned. maybe the ultimate mechanical uni-pivot. with the bridge the Durand's were not at all wobbly. but not plug and play easy to optimize.

on the FCL, with the field coil turned on, you can push from the side and it will deflect, and smoothly spring back. but zero wobble. the feel when putting side pressure on is more a slight resistance but controlled. whatever is actually happening and however it works, the result is ultimate (in my experience) standard setting information and musicality.

Aside from the fact that the strength of the magnetic field and its orientation with respect to the unipivot would or could make a big difference, why is the FCL superior to the best iteration of the Graham Phantom tonearm(s), which use permanent magnets to stabilize the bearing? I bring this up only for discussion; I have no preformed opinion, because I’ve used neither tonearm.

let’s just say that a passive magnet has performance potential; but a sufficiently engineered powered magnetic field has an apparently much higher effect on performance.

i’m not claiming any particular effect of the field coil. but i am saying that this arm performs beyond any i’ve heard. and then try to connect the dots as to why.

Mike, I do not doubt your testimony on iota.  I am just thinking out loud about the two kinds of magnet and why would an electromagnet outperform a permanent magnet in this application.  And of course, there can be any number of other reasons (such as field strength and field orientation for two examples or elements of construction totally unrelated to magnetism) why the FCL might outperform the Phantom (for one example of unipivot that uses permanent magnets).  Because in the end the "field coil" is here used as a magnet, so far as I can tell from the outside looking in.