Tone amplified! With its deluxe appointments and Fishman® Nashville pickup, the Bobtail Round-Neck stands out in the mix in more ways than one. The vital feature of all Gretsch resonator guitars is the Gretsch Ampli-Sonic™ diaphragm (resonator cone), which is hand-spun in Eastern Europe from nearly 99 percent pure aluminium, yielding an impressive quality and volume of tone.