The A15LA has a balanced bridging input with 50 dB attenuation. Use it to connect high-level line or Aux Outputs to low-impedance microphone inputs. It will attenuate the output from such devices as mixers, tape recorders, tuners, or phono preamps to make them compatible with balanced low-impedance units. The A15LA can be directly connected to either balanced or unbalanced sources. If the source is unbalanced, connect it to pin 2 (“hot”) and pin 1 on the A15LA input; no connection is required to pin 3. Frequency Response: 20 Hz to 20 kHz +- 0.5 dB Impedance: Input: 100k ohms; Output: 300 ohms Attenuation: 50 dB Maximum Input Signal Level: 40 dBV Connectors: Input: 3-socket female XLR; Output: 3-pin male XLR Case: Full magnetic shield, steel with gray enamel finish Dimensions: 19 mm (3/4 in.) diameter; 114 mm (4 1/2 in.) long Weight: 80 g (2.8 oz.)