Audio Technica UniPoint AT857AMLx, UniPoint AT857AMx Product Information

Description

The AT857AMx is a wide-range condenser
microphone designed for quality sound
reinforcement, professional recording, televi­sion, and other demanding sound pickup
applications. Standing 12.21" above the
mounting surface, its small-diameter alternat­ing gooseneck design permits highly flexible
positioning while maintaining a smooth, well­contoured appearance. The AT857AMLx is a

19.00" version of this microphone.
Supplied as a cardioid, the AT857AMx easily

accepts interchangeable elements to permit
selection of angle of acceptance from 100° to
360°.

The microphone features a 9.8' (3.0 m) per­manently-attached miniature cable. Its free
end connects to the provided AT8533x
power module via internal solderless screw
terminals for simple cable-length adjustment
in the field. It can be powered from any exter­nal 9V to 52V DC phantom power supply. A
recessed switch in the power module permits
choice of flat response or low frequency roll­off to help control undesired ambient or
mechanical noise.

The microphone element is enclosed in a
rugged housing with a low-reflectance black
finish. A 5/8"-27 threaded flange allows the
microphone to mate with the threads of a
standard microphone desk or floor stand. A

5

/8"-27 threaded stud is also provided so it can

be secured to a permanent mounting surface.

Installation and Operation

Output is low impedance balanced. The
output connector of the power module
mates with XLRF-type cable connectors. The
balanced signal appears across Pins 2 and 3,
while the ground (shield) connection is Pin 1.
Output is phased so that positive acoustic
pressure produces positive voltage at Pin 2,
in accordance with industry convention.

To attach the microphone cable using the
pre-stripped end:

Remove the three screws
from the base of the power module and slide
the outer case off to reveal the circuit board
and screw terminals. Next, slide the case
onto the cable (narrow end first), and tie a
single knot in the cable about 1" from the
tinned ends.

Do not pull directly on the

exposed small wires and shield.

Following
Figure 2 on the back of this sheet, attach the
wires to their respective terminals. Make
certain that the terminals are clamped on the
conductors, not on the insulation, and that
there are no loose strands of wire that might
touch other terminals. Replace the case,
being certain that it goes over the case
grounding contact and that the roll-off switch
is accessible. Finish by replacing the three
base screws and testing for proper operation.

To shorten the cable:

Remove the cable
from the module, and cut it to the desired
length (allowing a few extra inches). Next,
after sliding the case back onto the cable, tie
a single knot in the cable about two inches
from the cut end. Following Figure 1 on the
back of this sheet, cut the cable off 1" down

from the top of the knot and carefully remove

1

/2" of the outer jacket. Strip the mic cable
wires and attach them to their respective
terminals. Reassemble the module following
the instructions in the previous paragraph.

The provided AT8102 two-stage foam wind­screen simply slips over the head of the
microphone, effectively reducing wind noise
or “popping” when used extra close.

The small-diameter gooseneck is easy to
manipulate for proper positioning. Heavily
lubricated, it operates smoothly and quietly.
Should the unit become noisy with prolonged
use, apply a light machine oil directly on the
gooseneck area affected.

While a modern condenser microphone is
not unduly sensitive to the environment,
temperature extremes can be harmful. Avoid
leaving the microphone in the open sun or in
areas where temperatures exceed 110° F
(43° C) for long periods of time. Extremely
high humidity should also be avoided.

Architects and Engineers Specifications

The microphone shall be a fixed-charge
condenser with a cardioid polar pattern and a
frequency response of 30 Hz to 20,000 Hz. It
shall be capable of accepting optional inter­changeable elements for additional polar
patterns. It shall operate from an external 9V
to 52V DC phantom power source. Nominal
open-circuit output voltage shall be 7.0 mV at
1kHz, 1 Pascal. Output shall be low imped­ance balanced (200 ohms).

The microphone shall have a permanently­attached 9.8' (3.0 m) miniature cable with a
pigtail output. The pigtail output shall connect
to a power module via internal solderless
screw terminals. The power module shall
include a switch for low-frequency roll-off
and shall terminate in a 3-pin XLRM-type
output connector.

The microphone shall be a small-diameter
alternating gooseneck design, with a 12.21"
(310.2 mm) [19.00" (482.5 mm)] overall
length. Head diameter shall be 0.47" (12.0
mm). The microphone shall include a 5/8"-27
threaded flange to mate with the threads of a
standard microphone desk or floor stand. A

5

/8"-27 threaded stud shall be provided for per­manent installation to a mounting surface.
The microphone weight shall be 3.6 oz (103
grams) [4.6 oz (131 grams)], without cable.
Finish shall be low-reflectance black.

The Audio-Technica AT857AMx [AT857AMLx]
is specified.

AT857AMx
AT857AMLx

CARDIOID
CONDENSER
ADAPTER­MOUNT
GOOSENECK
MICROPHONES

Frequency Response

50

LEGEND

500

200100

Frequency in Hertz

12" or more on axis (flat)
Roll-off

2k

1k

10k

20k

5k

10 dB

Response in dB

200 Hz

1 kHz
5 kHz
8 kHz

LEGEND

SCALE IS 5 DECIBELS PER DIVISION

90

60

120

30

150

210

240

270

300

330

180

0

AT857AMx
AT857AMLx

Polar Pattern

AT857AMLx
Dimensions

Audio-Technica U.S., Inc., 1221 Commerce Drive, Stow, Ohio 44224
Audio-Technica Limited, Old Lane, Leeds LS11 8AG England

Form No. 0310-0857-00-B/W P50902 © 1996 Audio-Technica U.S., Inc. Printed in U.S.A.

0.47"

12.0 mm

1.39"

35.2 mm

310.2 mm

12.21"

30.0 mm

1.18"

2.6 mm

0.10"

3.58"

91.0 mm

0.83"

21.0 mm

AT857AMx/AT857AMLx SPECIFICATIONS

†

ELEMENT Fixed-charge back plate

permanently polarized condenser

POLAR PATTERN Cardioid (Unidirectional)
FREQUENCY RESPONSE 30-20,000 Hz
LOW-FREQUENCY ROLL-OFF 150 Hz, 6 dB/octave
OPEN CIRCUIT SENSITIVITY –43 dB (7.0 mV) re 1V at 1 Pa*
IMPEDANCE 200 ohms (1000 ohms without power module)
MAXIMUM INPUT SOUND LEVEL 138 dB SPL, 1 kHz at 1% T.H.D.
DYNAMIC RANGE (TYPICAL) 111 dB, 1 kHz at Max SPL
SIGNAL-TO-NOISE RATIO

1

67 dB, 1 kHz at 1 Pa*

SWITCH Flat response, low-roll-off (recessed)
PHANTOM POWER REQUIREMENTS 9-52V DC, 2 mA typical
WEIGHT MICROPHONE (AT857AMx) 3.6 oz (103 grams)

(AT857AMLx) 4.6 oz (131 grams)

POWER MODULE 2.1 oz (60 grams)

DIMENSIONS MICROPHONE (AT857AMx) 12.21" (310.2 mm) long above mounting surface

(AT857AMLx) 19.00" (482.5 mm) long above mounting surface
(BOTH) 0.47" (12.0 mm) head diameter

POWER MODULE 3.58" (91.0 mm) long, 0.83" (21.0 mm) diameter
OUTPUT CONNECTOR (POWER MODULE) Integral 3-pin XLRM-type
CABLE 9.8' (3.0 m) long (permanently attached to

microphone), 0.10" (2.6 mm) diameter,
2-conductor, shielded cable; free end attaches to
screw terminals in power module

ACCESSORIES FURNISHED AT8102 two-stage foam windscreen;

AT8533x power module;
AT8425 5/8"-27 threaded mounting stud

OPTIONAL INTERCHANGEABLE ELEMENTS AT853H-ELE hypercardioid (100°)

AT853O-ELE omnidirectional (360°)
AT853SC-ELE subcardioid (170°)

†

In the interest of standards development, A.T.U.S. offers
full details on its test methods to other industry
professionals on request.

* 1 Pascal = 10 dynes/cm

2

= 10 microbars = 94 dB SPL

1

Typical, A-weighted, using Audio Precision System One.

Optional Accessories:

• AT8104a metal lockable windscreen.

• AT8117 large foam windscreen.

• AT8314 2-conductor, shielded, vinyl-jacketed,
broadcast-type cable with XLRF-type
connector at microphone end, XLRM-type
connector at equipment end. Available in
10', 20', 25', 30', 50' & 100' lengths.

• AT8416 shock mount.

• CP8201 line matching transformer
(Lo-Z to 50,000 ohms).

• CP8506 four-channel 48V phantom power
supply (AC powered).

• CP8508 single-channel 24V phantom power
supply (AC powered).

AT857AMx

Dimensions

1.39"

35.2 mm

30.0 mm

1.18"

2.6 mm

0.10"

0.47"

12.0 mm

19.00"

482.5 mm

3.58"

91.0 mm

0.83"

21.0 mm

Shield strands,
fully twisted

Yellow-Yellow

Red-Red

1

/8" strip reds

and yellows

1

/2"

1"

One-Year Limited Warranty

Audio-Technica microphones and accessories purchased in the
U.S.A. are warranted for one year from date of purchase by
Audio-Technica U.S., Inc. (A.T.U.S.) to be free of defects in
materials and workmanship. In event of such defect, product
will be repaired promptly without charge or, at our option,
replaced with a new product of equal or superior value if deliv­ered to A.T.U.S. or an Authorized Service Center, prepaid,
together with the sales slip or other proof of purchase date.

Prior approval from A.T.U.S. is required for return.

This
warranty excludes defects due to normal wear, abuse, ship­ping damage, or failure to use product in accordance with
instructions. This warranty is void in the event of unauthorized
repair or modification.

For return approval and shipping information,

contact the
Service Department, Audio-Technica U.S., Inc., 1221
Commerce Drive, Stow, Ohio 44224.

Except to the extent precluded by applicable state law,

A.T.U.S. will have no liability for any consequential, inci­dental, or special damages; any warranty of merchantabil­ity or fitness for particular purpose expires when this war­ranty expires.

This warranty gives you specific legal rights, and you may
have other rights which vary from state to state.

Outside the U.S.A., please contact your local dealer for war­ranty details.

Terminal
screws

Case
grounding
contact

Yellow-Yellow
Red-Red

Shield

PC board

switch side

S Y R

Figure 1

Figure 2