Audio-Technica AT8531 Belt-Pack Power Module

The AT8531 is the belt-pack power module that sits between an Audio-Technica condenser and the console. It supplies the bias those capsules need and hands a standard mic-level output to the mixer, with a low-frequency roll-off switch built in to shed stage rumble and handling noise before it ever reaches the desk.

It runs from a single 1.5V AA battery or from phantom power, which is what makes it useful on a mixer that has no phantom supply at all. Input is on TA3M and output on an integral 3-pin XLRM. Audio-Technica lists it for the AT803b, AT831b, ATM73a, ATM75, U841A, U851A, U853A(W), U853A(W)U and U857A(W)U, and furnishes it with the U853, U857A, U841A and U851A.