When using the AudioSuite version of the BF‑3A, be sure to select an auxillary side-chain input (normally the track you are processing). The default is “None” and if you leave it set like this, there is nothing feeding the detector and you will not hear any compression action.Turn the Peak Reduction knob full counterclockwise (off) and use the Gain control to increase the signal level. Although the BF-3A does not compress the sound with these settings, it still adds its unique character to the tone.