ROLAND AF70 DI Anti-Feedback The ROLAND AF-70 automatically and precisely adjusts feedback (howling) with the push of a button. The high-precision anti-feedback filter is designed to pinpoint and suppress howling frequencies, minimizing changes in sound quality. It allows for quick settings to suppress howling during sound checks. The ROLAND AF-70 can also be used as a DI, and it has the necessary functions for DI use. Power adapter included.