ROD Harp Effects – Feedback P.I.

Feedback is an elusive criminal. That’s why you need a detective!

The Feedback P.I is a device that will help you eliminate the threat of feedback on any stage. It combines the three main approaches for fighting feedback all in one box: An active notch filter, a noise gate, and a Vol knob that can act as a PAD. The active notch filter will take care of the fundamental frequencies that are causing feedback. The Noise Gate acts as a life ensurance, cutting the signal while you are not playing. The Vol knob goes just a couple of decibels above unity, so it can be used as a PAD if you are forced to use a higher gain amp.

How to use:

1.- Set the VOL knob at unity (just a few degrees lower than fully clockwise).
2.- Start with the FREQ knob all the way to the right.
3.- Turn your amp and pedals past the feedback threshold. The idea is to intentionally create feedback.
4.- Once the feedback appears, start turning the FREQ knob to the left until the feedback goes away. You’ll likely find a few spots (or a range) where feedback disappears, but try to find the optimal position at the higher end of the frequency range.
5.- (Optional) Set the Noise Gate to 12 o’clock and engage the switch (up position). If your band is loud, you might need to turn the knob further to the right.
Volume: Set the Vol at unity if you are using a feedback-friendly amp. If you are using a high-gain amp, move the Feedback P.I to the end of your chain and set the Vol knob to 12 o’clock. This will turn the pedal into a PAD that will help to reduce the gain of the amp.

FREQ: This knob sets the frequency affected by the notch filter. It ranges from 400hz to 7000hz. The goal is to find the highest offending frequency. This will better preserve your tone.

ON: Turns the noise gate on or off. When off, the noise gate is bypassed.

GATE: Sets the threshold of the Noise Gate.

You can download the user manual from this link:

Download Manual