[English Translation Test Accuphase AC-6 / LP 01/2019]

1. The Golden
Number Five
Measured by the product change intervals in other equipment categories,pickups hold a special position in the Accuphase portfolio. All the more so thebrand-new AC-6.

The AC-6 is – you guessed it: the fifth pickup system in the Accuphase history. As it
is customary practice in the Asian region, the number four was skipped as a typename. The first Accuphase pickup cartridge, the AC-1, saw the light of the day in
1979, which was no less than seven years after the company start-up. Excessive
activism has never been a trait of the Japanese, and today things aren’t any different.
Hence the AC-6 is far more than just a slightly improved AC-5, which brought us joy
already well over seven years ago (see LP issue 6/2011).
The AC-6 is a classic MC pickup with 0.4 millivolts of nominal output voltage at one
kilohertz, thus it’s within normal range and won’t cause problems to any phono
preamp. The stylus compliance is specified with 8 µm/mN, a value which needs to be
graded at the lower fringe of ”medium-hard“. In other words: ultra-light tonearms are
not necessarily suitable game partners, but these are unusual today anyway. On aside note, its predecessor AC-5 featured a considerably softer suspension. The badnews about the AC-6 is: it costs almost 6,000 euros.
In a consistent way Accuphase relies on a light and rigid body. The generator ismounted on a titanium plate designed to pass on the energy as fast as possible. The
actual housing is made of extruded aluminum. Of course, the body shines in that
unmistakable Accuphase champagne tone which, like on the front panels, wasobtained by means of an anodizing process.
There’s little information on the generator itself. The magnetic field is provided by astrong neodymium magnet of the N50 class – the most powerful one can buy formoney and sweet words these days. The advantage of the thus achievable fieldstrength is that one can realize useable output voltages with a relatively low numberof turns in the coils. Which is precisely the case in the AC-6: at 1.8 ohms, the coils
are very low-Z. This would suggest that only very little wire was used to keep the1[English Translation Test Accuphase AC-6 / LP 01/2019]
moving mass very low. Moreover, a low generator impedance in conjunction with adecent output voltage enables a low-noise amplification of the tiny signals. The coils
are wound from OFC copper – for once, there’s no silver or gold to be found here.
For comparison: the good old AlNiCo alloy (aluminum, nickel, cobalt), for decades
the means of choice in loudspeaker as well as pickup building, yields only one ninthof the field strength that’s achievable with N50. We have no further information as tothe generator geometry and coil alignment, yet about the ”business end“ of thepickup: the stylus sits on a boron tubelet, at the end of which a semi-line contact
diamond is fitted. With a rounding radius of 3 x 30 micrometers, it’s a very sleek cut
aimed to ensure a maximum contact surface both at the edges and on the groove
bottom and thus an optimum energy transfer.
Being a genuine Accuphase product, the AC-6 is, above all, a feast for the eyes: adownright flawless workmanship graces this gem. And sadly rather the exception
than the rule in this day and age: it’s mounted absolutely correctly. Which means thatthe stylus support sits perfectly straight in the generator. The assembly is very easy,
the titanium carrier plate has M-2.5 thread holes in the standard half-inch clearance.
The front and lateral edges are perfectly straight and orthogonal to each other so that
one can simply use them for orientation during the installation procedure. The first to
be called up was the AC-6 in the Transrotor-SME 5009 on the Transrotor Alto fromthe previous issue – in terms of weight certainly close to the limit of what this pickup
should be paired with. The C-37 phono preamp, kindly supplied by German
Accuphase distributor PIA, was set to a terminating impedance of 300 ohms,
followed by Pink Floyd’s immortal masterpiece ”Wish You Were Here” hitting theturntable. With smashing success. The combination is flooding the whole room to its
farthest corners with music, the soundscape is huge, yet the proportions of thesingular events remain clear-cut and within their true dimensions. Sure, this is alegendary album and, of course, it sounds good, but such a phantastic sound from amore than 40-year-old record? This I had not expected. Soundwise the AC-6 goeseven one step further than the AC-5, if I remember correctly: the electronicallycreated parts of the album sound so beautifully soft like I’ve probably never heard it
before. By comparison, a Lyra Atlas plays with noticeably more wire and verve. TheAccuphase represents the Japanese art of pickup building in the best tradition; withits gentle immediateness it sometimes reminds of great Koetsu pickups. Vocals?
There is no better partner for this. Rickie Lee Jones serves her wealth of phrasingson a silver platter and sounds so marvelous that tears are going to well in your eyes.
Holger Barske2