Shure A15AS Switchable Microphone Attenuator

The Shure A15AS is a switchable inline attenuator designed to reduce microphone-level signals before they reach a preamp, mixer, or audio interface input. It offers three selectable attenuation levels—15 dB, 20 dB, and 25 dB—via a simple switch on the barrel, allowing audio engineers to dial in the right amount of signal reduction for the source at hand. This is particularly useful when close-miking high-SPL sources such as kick drums, snare drums, guitar cabinets, and brass instruments, where even a good preamp's input stage can be overloaded by the raw microphone output.

A key feature of the A15AS is its ability to pass phantom power through the unit, meaning it can be used with condenser microphones without interrupting their power supply. The device connects inline via standard XLR connectors—XLR input on one end, XLR output on the other—and requires no batteries or external power. It is a passive device that simply pads the signal level, introducing no coloration or noise of its own. Built to Shure's professional standards, the A15AS is a reliable tool for both live sound and studio environments where clean gain staging is essential.