Alternative names for "ZYX UNIverse" cartridge

All three coil versions have the same frequency response out to 100KHz.

Coil mass has nothing to do with the difference. The stylus movements are greater than the coil.

Silver is only 17% heavier than copper. Gold 3X heavier.

Silver has the highest conductivity of any metal, higher than copper or gold.

I have both the silver and copper coil Airy 3 SB's on identical arm tubes (VPI JMW10), that can be swapped in 30 seconds for comparison.

Silver takes a couple of months longer to longer to break in. IMO very similar sound characteristics, with the silver slightly warmer with more apparent high frequencies.

The British ZYX distributor stocks and prefers silver. Copper coil versions are special order.

The choice is a mater of taste.

Syntax, Thanks for helping me out on the Koetsu.

Doug, I would have written much of what Don wrote, to justify my doubts about cause and effect, but I did not want to get into it. Also, altho the fact that the difference in conductivity of silver vs copper and the difference in density between them would effectively cancel each other out, if both were equally important in winding the coil of an MC cartridge, I am not at all sure that conductivity makes that much difference; I think the amplitude of the signal generated depends only upon the number of turns of wire, the strength of the magnetic field, and the distance between them. Yet it's not hard to fathom that conductivity may also play a role. But if lowest moving mass was a central factor in "goodness", then moving iron cartridges would hold sway. (But maybe they do.)

Don_c55's description of the silver coils as "slightly warmer" matches my experience.

Copper = most neutral and dynamic
Silver = 17% warmer
Gold = about 3 times warmer

;-)

Interesting question, Lew. Unfortunately, as we know, there's no solution that doesn't carry its own problems.

MI cartridges differ from MC's and MM's in more than moving mass. An MI propagates the signal by causing one magnetic field to induce a response in another magnetic field. The induced response is necessarily phase-shifted from the original, more or less depending on the cartridge's design/build characteristics.

The audible effects of this phase-shift will depend on these characteristics and of course on the transparency of the entire system. At one end we hear mere "smoothing" or "sludge" (think, entry-level Grado). At the other end we may hear a distinct "echo", very disconcerting, at least to our ears.

The first MI I ever played caused Paul and me to wince. His quicker ears and brain let him instantly describe the phase-shifted echo that was the reason for our discomfort.

After thinking (and wincing) for about 30 seconds he asked, "Does this cartridge generate signal in some unusual way?". I confirmed that it did, and described how MI cartridges work. He rolled his eyes and nodded.

Without knowing anything about the cartridge (he'd never even heard of an MI) and with no prompting whatsoever, Paul heard this inherent characteristic and deduced that the generator wasn't a typical MM or MC design. Scary but true.

I think the amplitude of the signal generated depends only upon the number of turns of wire, the strength of the magnetic field, and the distance between them.

True. Of course the distance between them is a function of how far and fast the coils are displaced by a groove modulation. Now if coil A is has greater inertial mass than coil B...