Tranfiguration Orpheus description

The real reason for the increased output vs. impedance is a new core material (around which the coils are wound). This material was introduced by MySonic Labs' Matsudaira (formerly of Audiocraft) on his Eminent cartridges from a few years back.

One of Ortofon's newer SPU series (which I believe was also designed at least partly by Matsudaira) shares the same core material, and has similar output voltage vs. specs (something like 0.5mV with an internal impedance of 2ohms).

I believe that MySonic Labs shares a builder-craftsman with Immutable, hence the transfer of core materials.

Although the Eminent is highly regarded in Japan, production is very limited, so it may not be well-known in other countries yet.

Incidentally, both the Eminent and new SPU model use a traditional "Ortofon-style" magnetic circuit (with polepieces aka yokes and all), so it is doubtful if the choice of magnetic circuit has much to do with the increased output efficiency.

IOW, give ZYX or other cartridges the same core material and chances are that you'd get similar increases in output vs. impedance efficiency without much redesign effort required at all.

hth, jcarr

That ain't technical background, that's marketing speak :-).

Again, both the Eminent and Ortofon SPU Synergy (you can find these on the cartridgedb.com site) have a 1.8-ohm coil impedance and produce 0.5mV (measured at 5cm/sec). If we apply the sqrt 2 conversion factor (3.54 vs. 5cm) to the coil impedance, we see that putting a 2.5 ohm coil into the SPU Synergy or Eminent would yield 0.5mV @ 5cm/sec. No need for a yokeless magnetic circuit, just a suitable core material (and appropriate coil design) :-).

And FWIW, since the diameter of the coil wire can be either thicker or thinner, you cannot simply look at the coil impedance and deduce that the coil weight is lighter. A higher-impedance coil could be the one that's actually lighter, depending on the coil wire diameter specified.

Now don't get me wrong, I'm not trying to knock yokeless designs (I like them, too). But trying to draw a connection between yokeless and greater efficiency (output vs. impedance) isn't warranted, IME.

regards, jcarr

The diameter of the wire is also a component in deciding the sound, so rather than using the thinnest possible wire, a cartridge maker is likely to use whatever wire diameter that he (or she) thinks will give the right sound. In production you can go down to 15 micrometers (or even 12 if you don't mind somewhat higher than normal wire breakage), but based on my personal experience, I'd estimate that the Eminent, SPU Synergy and Orpheus all use considerably thicker wire - probably something on the order of 40 micrometers or even 45.

I quite agree with you that yokeless designs have certain advantages over traditional designs with polepieces (yokes). I simply don't agree that higher output efficiency is one of those advantages. Actually, if it is only output efficiency that you are pursuing, a traditional polepiece architecture is the easier one to do, first because the size of the magnet in a polepiece-based design can be far larger than what is practical in a yokeless design, and on top of that, the polepieces offer a greater degree of flux focusing than a magnet by itself can.

Incidentally, yokeless cartridges have been out on the market from the late 1970s, while as a subset of yokeless, designs involving ring magnets that fully surround the coils have been out since at least 1981, possibly earlier. So already a bit of time has elapsed since their introduction, certainly enough to refine the general concept :-). I do reckon that it is possible to refine the yokeless concept further, but then the same thing can likewise be said about polepiece-based designs. IME, neither one is maxxed-out yet, and each has a distinct set of trade-offs (advantages and disadvantages). A cartridge designer may validly prefer either, depending on his design goals, insights and resourcefulness.

A quick visit to the Stereophile website shows that they _have_ reviewed ZYX cartridges. At the very least they've reviewed the ZYX R-1000 Airy S, because they provide a link to an online review (done by Art Dudley in May 2004). Go to "Equipment Reviews", then "Phono Cartridges" within "Analog Sources", and you'll have the link.

BTW, among the other cartridge review links Stereophile provides, the Linn Akiva and Lyra Parnassus D.C.t are both yokeless/polepiece-less designs (albeit executed differently from the Transfigurations).

regards and hth, jonathan carr