· This floor version of Tech 21's RPM rackmount provides the same detailed tone shaping possibilities for any signal source. It is particularly useful with acoustic · electric and bass guitars · and upright bass · either direct to a mixing console or with an instrument amplifier. The Para Driver DI gives your instrument a natural warmth and presence · as if miking it through a tube pre-amp. The SansAmp circuitry eliminates the harsh · unnatural harmonics of piezo pickups · while the Drive control offers some tasteful edge - just a little or over-the-top.