What innovative, unconventional cartridge designs can you recommend?

I’d say the same for my Dynavector 17D3, though its cantilever is 0.4 mm longer than that of the Karat. Nevertheless an excellent performer.

@dover 

But the Neumann and ART1000 both have cantilevers wafting around upon which the coils are mounted

The diagrams I have seen of the Decca moving iron (MI) cartridge do label the structure holding the diamond stylus as a cantilever.  It is different in shape and position from typical straight cantilevers, though, and is made of iron.

Essentially it runs nearly vertically above the stylus, before doing a near right-angled turn towards the rear of the cartridge, where it is flattened into a flat spring shape and clamped in place.  The spring allows the stylus to move vertically through bending, and sideways through twisting (with different compliances!).

On its own, this (double?) cantilever does not prevent some unwanted fore-and-aft movement of the stylus, so a tie-back cord is added where a more conventional cantilever would run.  The actual cantilever is hidden above the lateral coil and magnet structure.

Have I got this right so far?  For the diagrams I am looking at, see for example Those Were The Days:Ortofon A/B, SPU, Decca London, Garrard GMC and Tannoy VariTwin Phono Cartridges

These diagrams also show damping medium (rubber?) attached to the flattened spring.

I don't think it is fair to suggest the ART1000 has its coils mounted to a cantilever which wafts around!  The coils are mounted almost exactly over the stylus as can been seen here Direct Power Stereo MC Cartridge | AT-ART1000x | Audio-Technica | Audio-Technica.  The cantilever exists solely to position the stylus in the body, and to stop it rotating.

@dogberry @viridian 

Surely the Neumann predates the Decca?

When I titled this thread "What innovative, unconventional cartridge designs can you recommend?" the words were carefully chosen to firstly not be click bait, and secondly to stop an eternal debate along the lines of my cartridge is better than yours!

In the latter aim, it seems to have succeeded.  We are now discussing just four families of cartridge designs, each of which has its sensors mounted close to the stylus.

The "can you recommend" was intended to influence an imminent buying decision.  While interesting historically, there was no intent to produce a timeline of who invented what, when.

Oh boy, That iron alloy structure works like this: imagine a long thin triangle of metal, then bend the point down 90° from the plane of the triangle. Now fashion that downward pointing part into a tube and plug a diamond stylus into it. Decca called the metal an ’armature’ and so should we. The metal triangle we started out with has a ridge stamped into it to provide rigidity so it will not exhibit unwanted movement beyond what might be required by lateral movement of the groove, which will cause slight torsional movement of the armature.

It should be obvious to all that this was designed for mono records, and is likely the very best way of reproducing them. What surprises me is that another set of coils was able to be placed to read vertical motion, and using a sum-difference wiring arrangement, stereo becomes possible. Bloody engineers, can no one stop them?

As for the ART1000 cantilever "wafting" around, it does so no more than any other cantilever. At least its transducer is close to the stylus, much more so than any conventional design (which is why extremely short cantilevers have been recently mentioned).

And the Neumann cartridge came along way after the original Decca. In fact, the Decca is an electronic adaptation of an acoustomechanical design from the days of wind-up gramophones.

But I agree, there is no reason to limit the discussion to which kind of tip-sensing cartridge is best. I'll leave it to you to figure out why that might be the way the thread has developed! 

@dover 

I've set up at least 30 Deccas, both original and modified, the original Ikeda MC and Decca's are certainly the quickest and most direct sound of any of the modern cartridges

Out of interest, are you including any DS Audio optical cartridges in your group of "modern cartridges"?

There is a review of the DS003 here DS Audio DS 003 Optical Phono Cartridge - The Absolute Sound where it is compared with the mega expensive Grand Master and the effects of trickle-down technology are explored.  Trickle-down is more like a tropical downpour.  The reviewer puts most of the sonic differences (not necessarily better or worse) down to the Equalizer, not to the cartridge.

DS Audio is a subsidiary of Digital Stream Corporation in Japan, who made major contributions to a device you are probably using now - the optical mouse!  It is hard to find a mechanical mouse these days.