● Pewter housing with manual mirror finish and rhodium and gold plating
minimizes vibrations and induction noise ● Microridge stylus shapeclosely resembles record cutter to ensure wide-range response ● Solidamorphous boron cantilever with high propagation speed● Samarium cobalt type 30 magnet with excellent thermal characteristics● “Real sound” type generating coil using 6N-LCOFC wire

Unlike CDs, playback of analog records in high quality requires dedication and anunderstanding of the various aspects of the process, making the enjoyment of musicwith this medium a special and truly rewarding experience. The C-27 Phono Equalizer
Amplifier from Accuphase has garnered high praise in the audiophile world. We are
now taking the next logical step in releasing the AC-5 MC Cartridge. Moving Coilcartridges from Accuphase have a long and distinguished this tradition, history,
beginning with the AC-1 in 1979, and followed by the AC-2 and AC-3. The AC-5 picks
up this tradition, while incorporating a new design and the finest materials available. It
was honed to perfection through extended
listening tests and is designed to ensure theultimate in analog record reproduction.
Phono Equalizer Amplifier C-27

Pewter housing minimizes vibrations andinduction noise
Pewter is an alloy of tin (Sn, 91%) with small
amounts of antimony (Sb, 7%) and copper(Cu, 2%). It has a beautiful silver-white sheen
and features just the right degree of rigidity toensure minimum self-resonance. For theAC-5, this material has been given a manual
mirror finish and rhodium and gold plating.

＊ The acoustic velocity of tin (Sn: 2,500 m/s) rivals
that of silver (Ag: 2,600 m/s).

R:60μmMicroridge stylus ensures long life and wide playback
frequency range
The diamond Microridge stylus developed by Namiki Precision Jewel Company provides wide frequency response forplayback. This stylus
shape, which is also
called a line contact
stylus (see Figure alarge curvature in thedepth direction andRidge: line contact

8-piece pure damper
The damper serves to support the vibrating parts such as
the armature (coil frame) and generator coils, while atthe same time controlling the vibrations in the system toachieve the correct damping characteristics. In the AC-5,only pure synthetic rubber without any additives is used
for the damper,
which is radially di- Damper
Armature
vided into eightequally sized sections. This uniqueconstruction (seeFigure 4) ensures
quick response toFig. 4 8-piece damper
vibration velocity changes and neutralizes elastic deformation stresses between the channels.

DiamondAA

Record groove

Solid amorphous boron cantilever with high propagation
speed transmits stylus movement with ideal fidelity

RidgemFig. 1 Microridge stylus
Fig. 2 A-A cross-section
view (Record-contactingR3μm section)

6μThe cantilever transmits the mechanical vibrationsof the stylus at one end to the electricity-generating
coil at the other end. It is therefore an important
link in producing an accurate electrical signal fromthe information engraved on the record. One of therequirements is high propagation speed, combinedwith high rigidity. The AC-5 uses a cantilever with
0.3 mm diameter made of solid amorphous boron.
This ideal material achieves a propagation speedof 16,200 m/s, far surpassing beryllium (12,870m/s) and approaching that of a diamond (18,350m/s). Since solid amorphous boron has a
non-crystalline structure, it is 3 to 4 times stronger
than crystal boron which consists of large crystals.

accuracy for both channels, resulting in improved
overall reproduction quality. The coils use highly pureoxygen-free 6N-LCOFC wiring with a diameter of 0.03
mm. Despite the low impedance of only 4.5 ohms, ahigh output rating of 0.24 mV is achieved.

1), has a small curvature in the effective tip whichcontacts the groove. This design significantly improves channel separation, frequency response andother parameters. A special feature of the ridge
shape is that it closely resembles the shape of therecord cutter. Even if the tip is diminished by wear,
the curvature radius will always be maintained at 3
micron (see Figure 2), which means long service life.

Samarium cobalt type 30 magnet withexcellent thermal characteristics“Real sound” type generating coils using
6N-LCOFC wire

The magnetic material used for the electromagnetic circuitry
is samarium cobalt type 30. Its Curie temperature, i.e. thepoint where the material loses its magnetism, is a very highof 700 to 800 degrees Centigrade. The fact that operation
remains stable at high temperatures translates into excellent
thermal characteristics also at normal temperatures.

In the groove of a phonograph record, in-phase
information is engraved in the horizontal direction andout-of-phase information in the vertical direction. The
AC-5 therefore employs a symmetrical coil arrangement
along the horizontal axis (see Figure 3). This prevents a
difference in sonic balance between the signal current
for the left and right channels generated by the coils.
Imaging and depth are recreated with exactly the same

The AC-5 comes in a very
handsome black lacquered box made of Japanesecypress wood. As shownin the photo at left, this canalso be used to house thecartridge with the head
shell attached, by using
the supplied shell holder
plate.

Vertical axis

Fig. 3−L-ch＋R-ch＋−−

L-ch＋＋
Horizontal axis R-ch
StylusConventional coil

● Stylus model magnified 2000 times

Wooden case also serves as shell holder−

StylusAC-5 coil＊ Head shell not supplied.
Please purchase a third-party head shell separately.

Dimensions and major structural parts

Frequency response (L channel)

Side view
19.5

4.1

Samarium cobalt type 30
0.3 mm dia.
Solid amorphous boron●Tracking force Recommended: 2.0 g
Range:
1.7 to 2.5 g

Material:
Curvature:
Service life:●Compliance

Microridge needle
diamond 0.1 mm sq.
3 µm x 60 µm
2,000 hours(tracking force 2.0 g)

Horizontal: 15 x 10−6 cm/dyne
Vertical:
12 x 10−6 cm/dyne●Output terminals:

1.25 mm dia.
(gold-plated brass)●Recommended load impedance
Amplifier: 100 ohms or higher
Step-up transformer:
10 ohms or higher●Cartridge weight:

Outputterminals

StylusRear view
3.2

Bottom view
112-M2.6

12.7●StylusCantilever

4.6

AC-5 Specifications

Moving coil
0.24 mV (1 kHz, 5 cm/sec)
4.5 ohms (1 kHz)
20 Hz to 20 kHz (±1 dB)
30 dB (1 kHz)
0.5 dB (1 kHz)80 µm/2.0 g (300 Hz)●Generating coil Wire material: 0.03 mm dia. 6N-LCOFC
Layout:Horizontal symmetrical●Magnet:●Cantilever:

7.8

4.2

●Cartridge type:●Rated output voltage:●Impedance:●Frequency response:●Channel separation:●Channel balance:●Trackability:

1.215

4.8

Front view
17

Right +Left +

Right –Left –

Serial number

Shell fastening screw holes

11.5 g (standard)● Specifications and design subject to change without notice for improvements.

Supplied accessories
Stylus cleaning brush (goat hair)
Stylus protector (transparent polycarbonate)●Fastening screws: non-magnetic titanium screws
M2.6 x 8 mm, 2 pcs.
M2.6 x 10 mm, 2 pcs.
●Mounting tool: Philips screwdriver●●L1005Y

PRINTED IN JAPAN

851-0200-00（B1）