From Gallien Krueger: The Fusion S Series Heads are GK’s brand new Class D Model heads with a tube preamp. 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. These high powered heads incorporate three 12ax7 tubes in the preamp, including one dedicated to the overdrive channel, making it GK’s first ever tube driven overdrive channel. Illuminated knobs add an extra level of sophistication and design by not only making it easier to dial in your tone on stage and but adding a beautiful stage presence as well. Each illuminated knob is also push activated, with additional voicing filters and tonal characteristics built in. Like the Legacy Series, the Fusion S series uses a unique interconnection system that eliminates problems that can develop over time from constant vibration and temperature extremes that gear is subjected to with heavy use. Using circuit boards with gold plated connectors, rather than cables with standard tin connectors, this type of construction delivers a more pure, reliable sound. Features include GK's classic 4 band EQ, tube Overdrive complete with tone shaping, additional push button voicing filters such as "Bump", "Contour", and "Presence", Balanced DI with Pre and Post EQ, an Effects Loop, Aux and Headphone connections, and Load capacity selection, to deliver optimum power into 2, 2.7, 4 and 8ohm cabinet configurations.