The Shure A85F is a low- to high-impedance microphone-matching transformer that provides 24 dB of signal increase gain. It has balanced female XLR and unbalanced high impedance male 1/4'' phone plug connectors, and may be used in reverse. The A85F is typically used to connect a balanced low-impedance microphone output to an unbalanced high impedance input on a mixer or recorder.

NOTE: Not for connection to the balanced line-level output of a mixer.