The Guild F47R Traditional Series Grand Orchestra Acoustic Guitar with D-Tar electronics features a solid red spruce top and bracing, solid rosewood back and sides, rosewood fingerboard and bridge, Gotah 500 tuners, tortoise binding, and the Guild D-TAR Pickup system. With the Grand Auditorium body style the Guild F47R exudes warmth yet has the volume and projection of a jumbo sized guitar. The D-TAR Wave-Length Pickup and Preamp System combines a thin, piezo under-saddle transducer with an 18v, low-noise, high input impedance preamp, to create a system with twice the dynamic range of typical 9v systems. The 18v preamp is powered by two "AA" batteries and a voltage converter. With 18 volts, the signal has more headroom, so hard strumming won't distort as easily. The preamp also has an input for a second source, like a magnetic pickup or a soundboard transducer.Two adjustable trim pots, one for low frequency shelving and one for high frequency shelving, allow you to fine tune and "set and forget" the bass and treble frequencies to optimize the Wave-Length for your instrument's size and shape; enabling you to transparently amplify the natural timbre of your acoustic guitar with minimal coloration. The soundhole mounted Volume and Tone controls give the ultimate in final control over your tonal palette.But perhaps the coolest part of the system is D-TAR's Load N Lock system, which allows quick and easy "AA" battery changes. Just unscrew the endpin "collar," remove the old batteries, and pop in the new ones. A quarter turn of the collar is all you need to lock them in place.