Optical attenuators are said to be unreliable or nonlinear such that channel to channel balance is tricky. I have no direct experience pro or con, except the testimony of an experienced audiophile that when working properly his was very transparent. I would think that DS Audio is aware of such issues and is careful about channel matching. And in any case, an attenuator is quite different from a phono cartridge. I’m interested in RB’s opinion once he’s had time to develop one.
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?
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Yes I’m also looking forward to @richardbrand thoughts on DS003 and how it works with the Soulnote phono equalizer |
I think @lewm and others here are entitled to ask what you mean by a TLA without having to look it up. I did look up FSE and the best fit was Fetal Scalp Electrode. Not sure if that is a misspelling! An alternative is Field Service Engineer but they normally visit customers. So please do explain what you mean by FSE? It is normal courtesy to spell a Three Letter Acronym (TLA) in full the first time it is used. Meanwhile it seems you have found a UFO who has convinced you what everybody else here knew intuitively - that the stylus shape and cantilever material are important for optical cartridges. Oops - I forgot. UFO = Unidentified Friendly Objector. Now we have to deal with your frankly ridiculous assertion that optical sensors are non-linear and highly variable, which would logically lead to poor channel balance. Does 0.3dB sound like bad channel balance to you? Every digital camera and digital movie camera relies on optical sensors. So does every optical mouse. Most astronomical telescopes, including the Hubble and Webb orbiting ones, uses optical sensors. The relevant physics operates at the quantum level, as described by quantum sceptic Albert Einstein. When a photon of the right energy is absorbed by a photodetector, it displaces exactly one electron. Nothing non-linear there. The process is stochastic, but billions of atoms will average out very well. There also nothing non-linear about the amount of shade cover provided to a photodetector in a DS Audio optical cartridge. Quite remarkably, Tetsuaki Aoyagi, who was awarded TAS' 2025 Inventor of the Year TAS-Fall-2025_Innovator-of-the-Year_Tetsuaki-Aoyagi.pdf, published the circuit design for Equalizers about 4 years ago to encourage other manufacturers to produce them in direct competition with his own. He provides technical support and there is no charge for other manufacturers, nor is there a licence fee. He believes, rightly in my opinion, that optical cartridges should become a mainstream choice like Moving Magnet and Moving Coil. |
Apparently, mine is winging its way from Japan, and will Likely Meet the Bulldozers destroying Mountains of Parcels at the POff, Next Week. If Customs does not get there first. They'll be collecting just 10% Goods and Services Tax. Looks as if I'll have to renounce my British Citizenship if I ever want to visit there again. No big deal, when I took my kids on a visit, they sauntered straight through on Aussie passports while I got royally interrogated by a gentleman from the sub-continent because I used my British one. |
If you are worried about non-linearities and poor channel balance, have a look at the Decca moving iron cartridges others have mentioned here. Originally designed for mono horizontal wiggles in the groove, the design was extended to cover vertical wiggles but the mechanicals are not symmetrical. leading to different compliances vertically and horizontally. Furthermore, the transducer design uses two coils in one direction, and one in the other. Single-ended versus double-ended. Lots of non-linearity there, not to mention extreme production variations. No, give me transducers arranged symmetrically at 45-degrees left and right to fit to my rather symmetric tangential Holbo tonearm! |
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