| I don't know about this unit, but generally resonators use a delay line with very short time (<15ms) and a very high feedback. This creates a resonance which is tunable by adjusting the delay time. So, whenever you play the note that the resonator is set to, it will be very loud, and every other note will sound like it's in an acoustic chamber with this particular resonating frequency. It's usually a kind of "metal tube" sound. | 
