Ampeg SVT 4 Pro bass head - pre-amp tube and transistor, 2x 300watts/8ohm RMS (900watts mono bridged), 2x 490watts/4ohm RMS (1200watts mono bridged), 2x 600watts/2 Ohm, 3 band EQ, 9 band graphic EQ, ultra low and high boost, effects loop, 19", 3U, Weight: 20kg.