Block Feedback! The Harp Shield Audio signals from the amplifier’s speaker are picked up by the microphone and fed back into the amplifier where it is amplified again resulting in what we know as feedback; the Harp Shield will prevent this process from ever starting by using noise gate technology. The Harp Shield is designed to mute the microphone when you are not playing by decoupling the microphone from the amplifier, thus preventing feedback. With the Harp Shield your microphone is muted when not playing and as you begin to play, the Harp Shield will unmute and allow your signal to pass through to the amp; when you stop playing, the pedal automatically mutes the microphone to prevent feedback. The pedal has a sensitivity control to prevent background noises from opening the audio path and inducing feedback. In the event that feedback does occur, just press the foot switch (a momentary switch) to reset the pedal and stop the feedback. When using this pedal, it is still necessary to use proper microphone handling techniques to help prevent feedback while playing. The Harp Shield differs from guitar noise gates in that the gate range is set for microphone levels and the fact that you will not lose any tone.
The only control is the SENSITIVITY control. With the control all the way the pedal is most sensitive and will allow virtually any signal to pass through the microphone; but, the mic will be more susceptible to a low volume noise opening the pedal and inducing feedback. Turning the control CW increases protection from feedback by requiring a higher level of audio to unmute the microphone and pass the audio. With the control turned too far CW you may not be able to pass audio while playing softly. The foot switch is a momentary non-latching switch; pressing the switch mutes the microphone (kills the audio) and resets the gate stopping feedback.