What innovative, unconventional cartridge designs can you recommend?

@lewm 

From where I sit, it seems there are more different optical cartridge equalizers on the market than there are optical cartridges.  Is that a fair conclusion?

Absolutely fair from my couch too.

Although, as others have pointed out, there have been previous attempts at making optical cartridges, the only real player in the market at the moment is DS Audio.

For equalisers, my reference is here DS Audio which currently lists 13 manufacturers and 21 models.  The list seems to grow almost by the day.

DS Audio currently makes six stereo cartridges and six (I think) mono variants of the same.  There will be older models as well.

DS Audio only seems to list third party manufacturers with credible world-wide distribution networks.  There are many more makers, especially in Europe, who lament not getting on to the list.

Only time will tell whether the market is oversubscribed.  If @pindac keeps up his diatribe ...

The beauty of DS Audio open-sourcing their phono stage design (that’s what it is after all, a phono stage) is that you or I can build one with $50 worth of parts if we wish. That, and it primes an ecosystem that supports optical cartridges.

If you’ve looked at the schematic, it’s not rocket science. If I recall, the biggest opportunity for differentiation lies in the output stage; you can make it as simple or as elaborate as you like.

I otherwise fail to see why cart and phono stage should be matched one-to-one, if in fact that’s what was being suggested. But maybe doing so does bring about a sonic benefit? I don’t know.

@devinplombier 

I believe it is far more difficult to manufacture the cartridges!  I have a highly magnified photograph of mine, and the precision is phenomenal.  What I originally thought were the shading plates are the optical sensors (the giveaway is a solder joint on each).  The actual shading plates are incredibly close to the sensors, and so thin as to appear translucent, or maybe it is beryllium shine.  They only have to block infrared.

Anyway, I can give some first impressions from my first two days with this cartridge, and they confirm any expectation bias I might have had 

Low bass is phenomenal, especially very low organ notes, which are particularly obvious in quiet passages.

Quiet passages are really, really quiet. The delicacy of the music shines though

Surface imperfections are mitigated, to the extent that records I got my money back on as unplayable have become useable and even pleasurable.  Seems that clicks, pops and scratches cause bigger changes in velocity than in position 

Fierce passages seem fiercer maybe because there is just so much detail.  Love ’em.

I have my SoulNote Equalizer set so I can switch to a MM cartridge on my Garrard with the press of a button, and a 5-second mute.  I have no doubt that the SoulNote is a far more detailed phono stage than my entry-level Krell pre-amp, even for MM.

With the DS Audio cartridge, the combination is stunning to my ears.  I suspect without any proof at all that the SoulNote outshines DS Audio Equalizers at the price point.  They have to, really, or there would be no point competing .  They have either got to be cheaper, or better, or both.

All the usual caveats.  The cartridge is not broken in and neither is the SoulNote.  My balanced cables are cheap 6-m microphone cables.  I am not a dedicated audiophile, I just love a small selection of classical music.  I have not connected my oscilloscope, nor done any other measurements.

@richardbrand that sounds fantastic! What kind of diamond and cantilever does your cart come with?

@devinplombier 

What kind of diamond and cantilever does your cart come with?

It is the cheapest but one!  Or the most expensive bar four.  The stylus is a 'line contact' and the cantilever is aluminium, probably a tube quashed flat at the end.

The cheapest stylus is elliptical so it would probably track the wear in my records very closely.  That's why I went up a notch.  I've just realised that the visible led on the front, which has no function except to show power is on, is colour-coded so afficionados can tell how much you spent!

From the amount of detritus that the stylus attracts, it covers a different part of the groove compared with my Micro-Ridge styli.

It seems to have more in common with the top-of-the-line cartridges than others in the range.  To quote Ken Kessler

“The DS 003 shows emphatically how trickle-down technology benefits the customer, while maintain a pecking order. As close as it is to the mind-boggling Grand Master, enough differences ensure that the two can co-exist: the DS 003 is the more lively of the two, the Grand Master the more subtle. That said, if you can afford a Grand Master, buy it. If you cannot, the astonishing DS 003 will still blow your mind” Ken Kessler Hi Fi News