HAO BL-1 Bass Liner EQ Effect Pedal Circuit designed by legendary audio engineer Phil Jones of Phil Jones Bass. Level Control offers up to +10 dB of signal boost. Hi-Fidelity, wide-dynamic range 5-band EQ with +/- 18 dB at 50 Hz, 160 Hz, 630 Hz, 2.5 kHz, and 12 kHz. Mute switch with Mute Status LED Mechanical True Bypass switching