What innovative, unconventional cartridge designs can you recommend?


Most cartridges have a stylus and cantilever where the transducer (magnet, iron or coil) sits on the far end of the cantilever.  What other designs are there?

I am mindful of two designs which put the business end right on top of the stylus.  The first is the moving coil (MC) Audio Technica AT-ART1000 which places two tiny coils, each 0.9-mm diameter, with eight turns of wire directly above the stylus.  Australian price is about AUD-7000 and there apparently is a newer model, slightly less exxe. the ART1000X.  This has square coils for a bit more output, and threaded mounting holes.

A downside is that stylus replacement involves a factory maintenance program and the Australian website page describing this service does not exist.

Another design is optical, exemplified by DS Audio's range.  While these still need a stylus to trace the groove, the signal is produced by reading the intensity of light produced by a Light Emitting Diode (LED) hitting two sensors.  Between the LED and the sensors are two 'shades' mounted above the stylus which change the amount of light as the stylus vibrates.  These cartridges need a special "photo-stage" to replace the conventional phono-stage which is an additional expense.

Australian prices including photo-stages range from AUD-2,150 for the DS-E1 to the DS Master 3 at approximately AUD-40,800, which is a bit outside my price range!  Where is the sweet spot?

What other way-out designs are there?

richardbrand

@audphile1 

I wish I could easily share SoulNote's 24 page branding document, which sets out several design philosophies, some of which are very challenging to old-school thinking.  Maybe your distributor can send you one.

Underpinning everything is the principle that the time domain matters, and frequency domain thinking stuffs up the time domain.

The document is derived from a 12-part series originally in Japanese with a fairy dodgy translation!.  Part 9 is Chassis Structure Affects Sound which includes

SoulNote products have unfixed top panel, unfixed board, unfixed terminal base, and thin and light cable

Part 10 is Physical damping (vibration isolation) blurs the waveform on the time axis.  It also talks about the role of air inside the cabinet, and makes the point that shelves should have openings and racks should be open.

Part 11 is Chassis Resonance with the thought that a monocoque, rigid design has more severe resonance modes than lightweight, loosely connected panels.

The printed circuit board is supported at three points and not fixed.  It is not fixed, but only placed on three pillars without stress, in order not to transmit the vibration of the chassis to the PCB and to avoid the strong resonance of the PCB itself

In my opinion, here is an engineer trying to understand what audiophiles have been reporting for ages, and translating the results back into practical engineering, albeit unconventional.  He claims that the market will decide if his theories are correct. 

Anyway, something does seem to be working and I don't believe in magic

I definitely trust they know their craft. I guess it’s a new concept for me. Do you feel the connectors moving when you are connecting cables?

@lewm 

RB, you wrote above, "So here is a practicing engineer who goes on to challenge the conventional view of audio as frequency dependent.  To him (and me) it should be time dependent." Can you amplify on that statement? Seems to me that frequency and time are not separable.

Yes, music comprises sound pressure levels which vary with time.  In nature, the only thing I can think of that interprets changes in these levels as frequencies is the ear canal.

Yet, historically audiophiles think in frequencies - the bass, the midrange, the treble etc.  And engineers use Fourier analysis to derive the frequency components in the original time signal.  Fourier analysis depicts sound as superimposed sine waves.which lend themselves to measurement.  Given the ability to measure, we get distortion readouts and introduce feedback to reduce the distortion in the frequency domain.  But feedback smears the time domain!  It is what SoulNote calls the Curse of the Fourier.

Take speakers for example.  If you just look at the frequency domain, you probably value a flat frequency response.  But that is much less than half the story.  Look at the speaker's response in time to an impulse, for example in a waterfall chart.  They really tell more of the story.

But look at how time stuffs up the sound from physically separate drivers, especially as it is characterised in the comb filter effect.  Even if you carefully time align the drivers to get coherent direct sound, the reflections are smeared in time and you are locked in to a small sweet spot.

That's why I like pseudo point-source speakers - your pseudo-line source speakers may perform the same coherence trick but I have not done the maths to fully convince myself.

The PRATs might have been right all along!

@audphile1 

Do you feel the connectors moving when you are connecting cables?

No more than the nervous twitches in my hands, which will get worse when holding a delicate optical cartridge worth thousands!

Seriously, I did not notice anything unusual but I only had two RCA connectors to push on.  Much prefer XLRs because of the reduced force required and the positive lock mechanism.

Do you feel the connectors moving when you are connecting cables?

No more than the nervous twitches in my hands, which will get worse when holding a delicate optical cartridge worth thousands!
 

Lol. You’re going to be fine.