ROLAND (M-CUBEGX) MICRO CUBE GX GUITAR AMPLIFIER - 3 WATTS. The New Standard in Ultra-Compact Amps!! A top-seller worldwide for nearly 10 years running, the MICRO CUBE is the most popular battery-powered amp of all time. ROLAND (M-CUBEGX) MICRO CUBE GX GUITAR AMPLIFIER - 3 WATTS. The New...