This multifunctional tool for acoustic musicians was conceived by Jacques Ruppert, mastermind of Ruppert Musical Instruments (RMI) and engineered by Lehle. It is a high end preamp in 2 channel design, with A/B switch for 2 instruments, a switchable parallel loop, a tuner-mute function and a DI out which is isolated by a Lehle transformer. As a special feature the Acouswitch, which serves as a central controller for acoustic setups, it has a body-contour-control to suit every musical environment: on the one hand a narrow notchfilter to reduce feedback with a frequency range of 45 Hz - 500 Hz, on the other hand it can boost a broad band of low to low-mid frequencies to make the sound fatter or make small speaker cabinets sound bigger.