Radial PZ-DI PZDI Peizo and Magnetic Pickup Selector / DI The Radial PZ-DI is a unique direct box that is specifically designed for acoustic and orchestral instruments.  Unlike most direct boxes that are limited to a "one size fits all" design, the PZ-DI lets you properly match the input impedance to the source to optimize the frequency response, dynamics and feel so that no matter what type of pickup you employ, you will enjoy smoother, more musically pleasing results. The design begins with a 3-position load adjustment switch: The 1 meg-ohm position delivers the classic impedance found on most active DI boxes.  The 220k-ohm setting warms up the tone of a magnetic pickup to give you the feel and tone as if connected to a tube amplifier.  The ultra-high 10 meg-ohm impedance is used to compensate for the harsh, squawky tone that usually plagues piezo-equipped instruments.  This is followed by a fully variable high-pass filter that lets you "size the instrument" by gently rolling off bass frequencies to eliminate unwanted resonance.  You could for instance, retain the low frequencies on a cello or increase the cut-off point to better suit a violin.  For active instruments such as acoustic guitars that incorporate a battery powered preamp, you can engage a low-pass filter to gently soften the hard edge for a smoother more natural tone. To maximize signal handling and reduce distortion, the PZ-DI incorporates an innovative DC to DC switching supply that converts the phantom p