What innovative, unconventional cartridge designs can you recommend?

@elliottbnewcombjr 

Thanks for the need for a SUT in addition to my MC input.  Puts me off the ART-1000X a fair bit, especially as I find out more about the unique features of the DS Audio series 3 range.

Conventional cartridges have to do physical 'work' as they generate electricity from the movement of the stylus.

DS Audio cartridges use an external power source, and the stylus does no work to generate electricity.  Instead electricity is generated when photons hit two light receptors.  The photons stream from two powered light-emitting diodes, one for each channel. In between the emitters and the receptors is a 'shade' made of extremely light beryllium, attached just above the stylus. 

The output of each receptor is proportional to the amount of shade not in the way.  Unlike conventional cartridges, the output varies with the position of the stylus.  Electromagnetic cartridges generate signals proportional to the transverse velocities of the stylus.  At the limit of excursion, DS Audio generates maximum output, conventional cartridges none.  That is why conventional phono stages won't process DS Audio output correctly.

The signal produced by the powered cartridges is huge, so signal to noise can be far lower.  I think I am sold, if only I had the money!

@richardbrand,

There is a stylus wear test being performed by Ray Parkhurst over at the Vinyl-Engine with some very interesting results; it's a 30-page thread, but starting at this page will give some insight - SWS3: Stylus Wear Study 3 - Page 24- Vinyl Engine.

The whole concept of the stylus bottoming is now being analyzed with the details showing that records are cut differently which can impact when the stylus bottoms-out.  There is a lot to digest.   

The Soundsmith strain gauge cartridge. It eliminates the RIAA- equalized phono stage.

@cleeds 

There are those that claim a stylus at typical VTF exerts many tons of pressure at its tip. That isn’t true, either.

I am writing this before diving into @antinn 's references but here's my back of the envelope thoughts!

One ton is about 1000-kgs, and pressures used to often be stated in tons per square inch.  For example, mild steel had a tensile strength of about 40 tons per square inch (before SI forced the Pascal on us).

So one ton is a million grams, and the pressure of one ton/sq in = the pressure of one gram per millionth of a square inch.  The same as a square with sides a thousandth of an inch.  There are about 25 mm to an inch, so 25-microns per side.

The half-wavelength of a 20-kHz tone towards the inner limit of a record is about 5 microns. The combined length of both groove walls is about 50-microns. A line stylus with a downforce of 1 gram, that completely fills a half wavelength, would exert about 25 / 5 x 25 / 50 or about 2.5 tons per square inch.  Double the downforce and you get 5 tons per square inch.  Change to a less filling stylus shape, and the numbers go up again

richardbrand OP

"Thanks for the need for a SUT in addition to my MC input."

Noooooo, you need one or the other, not both. An MC Input typically has enough gain for LOMC Low Output Moving Coil cartridges, (that would include the 0.22mv of the ART1000x) and they also include RIAA Equalization, the end result is a LINE level signal.

SUT Step Up Transformers are used to simply pre-boost the signal strength enough to use a typical MM Moving Magnet Input, which then performs both some boost and RIAA Equalization.

RIAA Equalization must occur somewhere, but not twice.