Source Audio ZIO Analog Front End + Boost เอฟเฟ็กต์ Make everything sound better with any of ZIO's four all-analog preamp circuits. Punch your signal with up to +20dB of boost. The goal in creating the ZIO Analog Front End + Boost was simple yet ambitious: “Make Everything Sound Better!” ZIO is an all-analog preamp/boost pedal from Source Audio that includes a choice of four distinct preamp circuits, each with up to 20dB of additional output boost. ZIO is Source Audio’s first all-analog effects pedal and designed in collaboration with Christopher Venter, the owner and sole engineer at SHOE Pedals.