The SM83A Wired Lavalier Microphone with a suppliedamplifier assembly, features a 12 dB/octave rolloffbelow 100Hz to help reduce room noise and other undesirable low-frequency signals. The SM83A consists of the 83A microphoneelement and an amplifier assembly with an attached 3 m (10ft) output cable terminated by a three-pin professional (XLRtype) audio connector.The SM83A is powered either internally by a readily available9-volt battery (not supplied) or externally by phantom powersupplied by broadcast, sound reinforcement or recording equipment, or an external phantom supply. An automatic powerswitchover feature provides automatic switching from battery tophantom power. The SM83A operates over an extremely widevoltage range of 11 to 52 Vdc, covering both DIN and IEC phantom power standards. A dual-channel power supply (ShureModel PS1A) is available for providing phantom power to theSM83A.