Audio-Technica MICROLINE AT915AMRX/ML - Manual

AT915AMRx /ML
MicroLine

Description
The AT915AMRx/ML is a wide-range con-
denser microphone with a MicroLine  polar pattern.
It is designed for quality sound reinforcement,
professional recording, television, and other
demanding sound pickup applications. The
small-diameter alternating gooseneck design
permits highly flexible positioning while maintain-
ing a smooth, well-contoured appearance. Its
adjustable-length design allows for the ultimate
in positioning flexibility. The AT915AMRx /ML
features a
5 / 8 "-27 threaded flange that allows it 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.
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
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
roll-off to help control undesired ambient noise.
Four additional interchangeable elements
are available to permit selection of angle of
acceptance from 90
° to 360 ° .
Audio-Technica design engineers have utilized
the newest low-mass diaphragm technology in the
quest for superior performance. The permanent
charge is now on the fixed back plate, rather than
the moving element. With A-T fixed-charge “back
plate” construction, a gold-vaporized diaphragm
just 2 microns thick (about .000079") can be used.
This considerably reduces moving mass, thus
improving frequency response and transient
response while reducing distortion.
The microphone is enclosed in a rugged
housing with a low-reflectance black finish.
Installation and Operation
Output is low impedance balanced. The out-
put 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 ter-
minals. 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 3,
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 2, 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.
By removing an attached AT8533x power
module, the cable from the microphone can be
routed through the bottom of the flange instead
of exiting from the side as supplied (Fig. 1).
The provided foam windscreen simply slips
over the MicroLine element, effectively reducing
wind noise or “popping” when used extra close.
The small-diameter gooseneck is easy to
manipulate for proper positioning. Heavily lubri-
cated, 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, tempera-
ture extremes can be harmful. Exposure to high
temperature can result in gradual and permanent
reduction of the output level. 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.
Figure 2 Figure 3
Figure 1. Cable routing
Frequency Response (Typical)
LEGEND
Roll-off
12" or more on axis (flat)
Frequency in Hertz
Response in dB
10 dB
20k 10k 5k 2k 1k 500 200 100 50
Shield strands,
fully twisted
Yellow-Yellow
Red-Red
1 / 8 " strip reds
and yellows
1 / 2 "
1"
Terminal
screws
Case
grounding
contact
Yellow-Yellow
Red-Red
Shield
PC board
switch side
S Y R
Miniature
Condenser
Adjustable -
length
Gooseneck
Adapter-
mount
Microphone