Offering outstanding Audio-Technica sound for surface-mount applications, the U851A features a PivotPoint® rotating output connector, UniSteep® filter and UniGuard™ RFI-shielding technology. This battery- or phantom-powered condenser microphone accepts interchangeable condenser elements—available for boundary microphones in cardioid, hypercardioid and omnidirectional polar patterns. Its heavy die-cast case and silicon foam bottom pads minimize coupling of surface vibration to the microphone. With superior off-axis rejection and maximum gain-before-feedback, this professional microphone sets audio-quality standards in challenging acoustic environments.
Specifications
- Element: Fixed-charge back plate, permanently polarized condenser
- Polar Pattern: Half-cardioid (cardioid in hemisphere above mounting surface)
- Frequency Response: 30-20,000 Hz
- Low Frequency Roll-Off: 80 Hz, 18 dB/octave
- Open Circuit Sensitivity: Phantom: –40 dB (10.0 mV) re 1V at 1 Pa Battery: –41 dB (8.9 mV) re 1V at 1 Pa
- Impedance: Phantom: 200 ohms Battery: 270 ohms
- Maximum Input Sound Level: Phantom: 133 dB SPL, 1 kHz at 1% T.H.D. Battery: 123 dB SPL, 1 kHz at 1% T.H.D.
- Dynamic Range(typical): Phantom: 111 dB,1 kHz at Max SPL Battery: 101 dB, 1 kHz at Max SPL
- Signal-to-noise Ratio: 72 dB, 1 kHz at 1 Pa
- Phantom Power Requirements: 11-52V DC, 2 mA typical
- Weight: MICROPHONE: 244 g, POWER MODULE: 139 g
- Dimensions: MICROPHONE: 4.25" (108.0 mm) long, 3.31" (84.0 mm) maximum width, 0.91" (23.0 mm) height, POWER MODULE: 3.31" (84.0 mm) H x 2.48" (63.0 mm) W x 0.87" (22.0 mm) D
- Switches: Off, on-flat, on-roll-off
- Output Connector: Integral 3-pin XLRM-type
- Accessories Furnished: AT8531 power module; battery; soft protective pouch









