Data Sheet

broadcast & production microphones
AT875R
Line + Gradient Condenser Microphone
Features
• Designed for video production and broadcast (ENG/EFP) audio
acquisition
• Extremely short length and light weight ideal for use with
compact digital cameras
• Provides the narrow acceptance angle desirable for long-distance
sound pickup
• Smooth, natural-sounding on-axis audio quality
• Tailored response minimizes camera and handling noise
• Rugged design and construction for reliable performance
Description
The AT875R is a xed-charge condenser microphone with a line +
gradient polar pattern. It is designed for video production and broadcast
(ENG/EFP) audio acquisition.
The microphone requires 11V to 52V phantom power for operation.
The microphone's highly directional polar pattern provides a narrow
acceptance angle along with crisp, intelligible audio reproduction
desirable for long-distance sound pickup.
The output of the microphone is a 3-pin XLRM-type connector.
The microphone is enclosed in a rugged housing. The included AT8405a
stand clamp permits mounting on any microphone stand with
5
/
8
"-27
threads. A windscreen, two o-rings and a soft protective pouch are also
included.
Operation and Maintenance
The AT875R requires 11V to 52V phantom power for operation.
Output is low impedance (Lo-Z) balanced. The signal appears across Pins
2 and 3; Pin 1 is ground (shield). Output phase is “Pin 2 hot”— positive
acoustic pressure produces positive voltage at Pin 2.
To avoid phase cancellation and poor sound, all mic cables must be wired
consistently: Pin 1-to-Pin 1, etc.
The high sensitivity of the microphone assures useful output and an
excellent match to most input sources. In some cases, however, an
attenuator may be required between the microphone and preamplier to
avoid overloading sensitive input stages.
Avoid leaving the microphone in the open sun or in areas where
temperatures exceed 110° F (43° C) for extended periods. Extremely high
humidity should also be avoided.
Note: To use the microphone with a camera-mount microphone holder
whose diameter is too large to secure the microphone, slide the two
supplied o-rings onto the microphone handle, spaced so that one ts
just in front of, and the other ts just behind, the rubber nubs inside the
microphone holder. When the top of the microphone holder is closed and
tightened down, the o-rings should hold the microphone securely in place.
Architect’s and Engineer’s Specications
The microphone shall be a xed-charge condenser. It shall have a line +
gradient polar pattern and a frequency response of 90 Hz to 20,000 Hz.
The microphone shall operate from an external 11V to 52V DC phantom
power source. It shall be capable of handling sound input levels up to
127 dB with a dynamic range of 107 dB. Nominal open circuit output
voltage shall be 31.6 mV at 1 V, 1 Pascal. Output shall be low impedance
balanced (100 ohms).
The output of the microphone shall be a 3-pin XLRM-type connector.
The microphone shall be 175.0 mm (6.89") long and have a diameter of
21.0 mm (0.83"). Weight shall be 80 grams (2.8 oz). The microphone shall
include a stand clamp, a windscreen, two o-rings and a soft protective
pouch.
The Audio-Technica AT875R is specied.