How Audio-Technica Builds the ART1000 MC Phono Cartridge (price and tech correction)

During my visit to Audio-Technica in Machida City, Tokyo, Japan, I was I given a tour of the factory, which mostly produces microphones along with some headphone components. Other than the new ART1000, all of the cartridge manufacturing and assembly takes place either at another factory in Fukui, Japan or at an Audio-Technica owned factory in China.

The ART1000 is manufactured in a small corner of the Machida City factory where one well-trained woman is responsible for the nearly impossible task of assembling the special cartridge. I saw her do it, but was not allowed to video the process. However, I was given permission to describe it.

First, aided by a microscope she winds the tiny coils a specified number of turns on a specially made miniature coil winder. Because it's not wound on a former that becomes part of the finished cartridge, once it's wound on a tiny bobbin she carefully applies alcohol from a tiny diameter dispenser that melts the wire's enamel layer, which quickly re-hardens, thus maintaining the coil's round shape. It's then removed from the bobbin, after which she carefully dresses the tiny diameter leads. A pair of the end products looks like this:

Next, she carefully places a tiny clear, stiff, translucent film onto a work space under a powerful microscope. The film has two precisely placed circular recesses into which she has to carefully maneuver the two coils, one at a time. There's no room for error. The tiny coils must fit perfectly within the shallow circular recesses. They are placed one at a time and then each is affixed with another drop of alcohol. If the coil accidentally moves before it's fixed on the film, all of the work is for naught and she has to start over.

Once both coils have been properly affixed to the film, a special jig is used to hold the film in place while she uses tiny tweezers to place the cantilever/stylus assembly in place atop the film/coil assembly.

Again, there's no margin of error. Now she has to carefully affix with adhesive to the top of the stylus shank the film containing the coils.

When that assembly is complete, she next has to carefully thread the damper assembly onto the cantilever and using another special jig created by the cartridge designer Mitsuo Miyata, she places the cantilever into the rear "pipe" and tightens the tiny grub screw, completing the coil/stylus/cantilever assembly.

Well not quite: she also has to dress and flatten the tiny coil wires atop the cantilever and again, using alcohol, neatly to melt the enamel, fix the wires in place.

The above photo shows what the final assembly looks like, though the actual one is far smaller. The cartridge body is machined Titanium. Each cartridge is then tested for all of the usual parameters. Because the positioning of the coils in the magnetic gap is so 'severe' and critical, each cartridge comes with its own precise tracking force specification. There's no recommended range. You have to set it precisely as recommended for your particular sample, though they are all within a small range.

The image at the top is of a rejected, assembled cartridge. As you can see the coil profile does not sit centered in the gap, and therefore all of this work is for naught.

This is why assembly takes so long and only two hundred can be built annually. And it also helps explain the $5000 cost. Is it worth the money? Read the review in an upcoming Stereophile "Analog Corner". However, before that's published we'll post a 96/24 file here on analogplanet.com that you can download and listen for yourself!

And of course all of this helps explain why, should your ART1000 need a "re-tip" it will cost more than the usual 're-tip' cost: approximately 65% of the cost of a new ART1000.

COMMENTS
sommovigo's picture

I'm thinking it probably was alcohol, used to dissolve the outer layer of the enamel on the wires in the coil so that they'd gummy-up and stick together. Looking forward to hearing the download!

Michael Fremer's picture
I have amended the story. Thanks.
Eskisi's picture

May be this is already mentioned in the interview which I am yet to watch, but is the coil arrangment in effect a more "exposed" version of the captioned cartridge from 1986?

avanti1960's picture

Thanks Michael and to A/T for sharing the process!

PAR's picture

I am really looking forward to hearing that file and to the review.

In the meantime and coincidentally I was recently speaking with a truly legendary audio designer on matters phonographic and this design came into the discusssion. He said that he is concerned about the effect of adding the mass of the coils at this location on the cantilever. That ertainly seems a valid thing to consider.

BTW I will not identify the designer as I have no permission to associate this remark with him in a public forum. On the other hand I cannot claim it as my original thought.

thomoz's picture

The show sounded utterly amazing. This cart tracks fantastically clean and has oodles of detail without the treble boost

apaya's picture

Michael,
I hope you had the time to at least visit the Diskunion Jazz record store in Shinjuku during your visit. It is great to see old and new Blue Note releases side-by-side as well as record stores packed with customers!
I have managed to spend entire days in the various Shinjuku Diskunions.
Armin

gorkuz's picture

PAR,as with all engineering, it's a choice of trade-offs. You bring up a legitimate consideration.

On one hand, mounting the coils there means elimination or at least reduction of slop/flex and resonance from the cantilever. Almost certainly the reason for this placement. OTOH, there's the mass issue of the placement legitimately brought up. Not just the raw mass, but its balance. Any off-centering can cause the micro-twisting of the cantilever if the mass is not perfectly balanced relative to the vertical plane of the cantilever and therefore an effect on the azimuth of the stylus. If short of perfect alignment (in the real world) the effect can be of the stylus tip kicking around left-right (radially relative to the record center)as the stylus goes micro-bashing its way down the groove...

You make your choices and you listen to the results. Evidently, the designer and AT thought this worthwhile. The rest is up to our ears and tastes...and wallets.

IK

gorkuz's picture

Thought I'd add that even if that mass is perfectly balanced, twisting will still occur due to the groove walls being at 45 degrees to the vertical. As the groove walls apply impulses to the stylus, the coil mass will try to lag that motion, causing torsional twisting. With the longer unsupported length of the cantilever being at the stylus end, this is more significant than were these at the other end.

IK

X