The GD30CE-12 sports Takamine's TP-4TD preamp, giving you rich, clear amplified output, instantly. Takamine G-Series guitar includes a TP-4TD features a gain knob; a tuner; an active shelving EQ with bass, middle, and treble sliders; and a low-battery indicator. The preamp is switched on by plugging a standard instrument cable into the end pin/strap pin jack. Unplugging the cable turns the preamp off. The TP-4TD is powered by a single 9-volt battery.