The Gallien-Krueger Fusion 550 incorporates a unique six stage tube pre-amp paired with a high current solid state power amp. The rich warmth of tubes, combined with the quick, punchy power section that GK bass amps are known for is an experience like no other. In addition, GK takes the next step in innovation by adding motorized controls which allow you to store two different settings that can be recalled via the included footswitch.The Gallien-Krueger Fusion 550 delivers a massive 500 of power at 4 Ohms (350 watts @ 8 Ohms) and features a unique 50-watt horn bi-amp system with a dedicated control knobs to dial in the level of the horn when you're in bi-amp mode. The pre-amp is powered by a trio of 12AX7 tubes for that classic tube warmth and richness. For superior sound-shaping capabilities at all frequencies, the Fusion 550 sports an active 4-band EQ (Bass, Low-Mid, High-Mid, Treble) as well as a Shaping section that consists of a Bright switch, a Deep switch, and a Contour control knob that works in tandem with Mid Frequency switch. Other pro-grade, premium features include an Effects loop for use with external effects, a Tuner output with mute switch, Speakon & 1/4" outputs, and an XLR output with a Level control, Ground Lift switch, and Pre/Post EQ switch.Get your Gallien-Krueger Fusion 550 Hybrid Bass Amplifier Head today at the guaranteed lowest price from Sam Ash Direct with our 45-day return and 60-day price protection policy.