Audio-Technica AT915AMRX/ML manual Description, Installation and Operation

Description

The AT915AMRx/ML is a wide-range con- denser microphone with a MicroLineâ 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

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).

Figure 1. Cable routing

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.

	Frequency Response (Typical)
									in dB
								10 dB	Response
50	100	200	500	1k	2k	5k	10k	20k

AT915AMRx/ML

MicroLineâ

Miniature

Condenser Adjustable- length Gooseneck Adapter- mount Microphone

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

Frequency in Hertz

LEGEND12" or more on axis (flat)

Roll-off

Terminal screws

Case grounding contact

	Shield	Y	R
1"	S
	Yellow-Yellow	PC board
1/2"
	Red-Red	switch side

1/8" strip reds

and yellows

Shield strands, fully twisted

Yellow-Yellow

Red-Red

the case back onto the cable, tie a single knot in

Figure 2 Figure 3