Demagnetise your moving coil cartridge
Welcome to the latest addition to the LJC Hi Fi Toys Collection: a moving coil cartridge demagnetiser, from US manufacturer Aesthetix. Delve into the murky and sinister world of hi-fi accessories. Forget which pressing sounds best: make them all sound better!
If you already own an moving coil cartridge demagnetiser, don’t have a moving coil cartridge, or don’t have a turntable, just listen to music on your phone, or came here due to a Google search error looking for the London Jam Collective, look away now. If you own an moving coil cartridge and haven’t had it demagnetised, read on.
Magnetism is a problem I didn’t know I had, until one of these came along and solved it. After unplugging the tonearm leads from the back of my phono amp, and hooking them up to the demagnetiser for the required 10 to 15 seconds operating cycle, the change in performance of my system was immediate and frankly, laugh-out-loud astonishing. This is not a subtle improvement, it is audibly significant.
Moving Magnet vs Moving Coil cartridge
Moving Magnet (MM) cartridges consist of a magnet mechanically connected to the end of the cantilever, which moves within a pair of coils to generate a stereo signal.
Moving coil cartridges are an inverted moving magnet design. The magnet is stationary within the cartridge body and the coils are moved by the stylus/cantilever. Moving coils generate a much smaller electrical signal than their moving magnet counterpart, which require a further stage of amplification (phono amp)
Science or Voodoo?
The coils of a moving coil cartridge acquire magnetism over the course of time, which gradually impairs the sensitivity of the cantilever, affecting high frequencies most.
You are unlikely to be aware of coil magnetic impairment, as it builds up slowly over time, unrelated to the amount of cartridge use. It is audibly transformational when removed, especially to a cartridge that never been degaussed over years of use.
Demagnetiser in operation
The Aesthetix unit is about the size of a packet of cigarettes (if you can still remember cigarette packets). It runs on a couple of 9v batteries, and is fully free standing in operation. Unplug the leads coming down from the tonearm to the phono amp, and plug them instead into the sockets at the back of the Demag unit. Push the power button, which lights up, then press the activate button. The unit sends a sine wave up through the leads into the cartridge coils for about ten seconds, and then switches itself off. It is the same process as degaussing tape heads, only for moving coil cartridges.
You see above the highly complex phono interface in the back of the unit. Two plug connectors, one for left and one for right channel. Just plug and go.
The before and after performance on the same LP track was illuminating, a lifting of veils, lots of them. The clarity and precise definition of my Dynavector TKR was immediately restored to its original beauty. What I realised with hindsight was that, over time, the sound had become muddy in comparison, the bass tending to bloom. Back came the tuneful bass, liberating the middle and top end to sparkle.
Aesthetix recommend a demag session every couple of weeks to keep your mc cart in top performing condition. I’m not convinced you need it more than every six to eight weeks. Unlike the promise of new and better equipment, a demagnetiser doesn’t add anything. It merely restores the performance you have already paid for. If you bought a sow’s ear, it remains a sow’s ear and does not become a silk purse.
Caution: demagnetizing does not work with moving magnet (MM) cartridges, only with MC cartridges. It passes a sine wave through the moving coils. You not want to demagnitize MM magnets.
I have a Dynavector TKR moving coil cartridge and I consider the demagnetiser an essential part of my musical armoury. (If you want a home demonstration, after my call-out fee, mileage and hourly consultancy rate, it is cheaper to just buy one)
The US-made Aesthetix ABCD-1 currently costs £200 GBP , around $300 USD, or whatever the hyena hedge-fund speculators have decided the GBP/USD rate should be today. (Brexit! Ukraine! Oil prices! My next Lamborghini!)
The Japanese developed a similar device, the Luxman X1A, whose operation is described thus:
The coil bobbin of MC cartridge is always susceptible to magnetism. The magnetised bobbin can respond to large movement of stylus tip and cantilever, but cannot generate electricity according to minute movement, thus degrading reproduction of subtle music signal and treble frequencies.
The Luxman is found as New Old Stock located in Japan, on eBay around $150 . Looks a lot chunkier, and gold colour, not out of place in a ’60s sci-fi movie. Full warp speed ahead, Scotty, degauss!!
Gryphon Black Exorcist MC cartridge demagnetizer: $230
Made in Denmark, The Black Exorcist uses a similar sinewave sweep tone to demagnetize a cartridge’s coils. “The Gryphon is very nicely made and works as well as any demagnetizer I have tried,” said Michael Fremer
“Gryphon recommend heavy vinyl users demag their cartridges once a month. They suggests that the demagnetising process take place with the stylus resting on the record. Not rotating, of course. This device restores the magnetic properties of your cartridge to a near-new state”.
The UK has only one main importer/distributor of the Aesthetix, Cool Gales in Bath. The US manufacturer also has other distributors worldwide. The Gryphon Black Exorcist is also available as whole system demagnetiser, which sounds to me a bridge too far.
The Aesthetix Demagnetiser is not “cheap”, but in terms of what it delivers, it’s a steal compared with other hi-fi improvements, such as high-end cables or those five foot high speakers you keep promising yourself.
I did a demag today after a couple of months, and the uplift was immediate: spine-tingling, more detail, more definition, more excitement, sharper imaging, beautiful.
Magnetism also affects the composition of vinyl records. I heard the Furutech Vinyl Demagnetiser demonstrated at a high-end hifi show. It amazed a room full of sceptical high-end audio listeners, but the workload is demanding, you have to demag every LP every time before every play, it has no lasting effect on the LP. At around fifteen times the cost of a cart demag no one was rushing to buy one. Me neither, but beware the hifi curmudgeon, there was no question it made significant improvement.
I bought the Aesthetix myself, not a review sample, and I have no financial interest, merely passing on an experience you may not have known about or considered. It is a good and very cost-effective product which gives you more enjoyment from your investment in records, and deserves commercial success.