The UltraPure System is an active (pickup + preamp) system for acoustic guitar. It consists of our award-winning Pure Pickup, an onboard preamp with soundhole access, an endpin jack, and a Velcro mounted 9-volt battery holder. The newly designed UltraPure Preamp features +/-20 db bass/low, K&Ks proprietary wide band midrange, and treble/high controls, plus internal gain trimmer. The addition of a phase switch is one of the most important tools for live sound amplification. Also includes a volume control and low battery indicator. All features are easily accessed at the soundhole.