For years bassists have been combining guitar and bass amps to remarkable effect, adding harmonics and layers of overdrive from a guitar amp to their core bass tone in pursuit of the ultimate live sound. This ‘bi-amp’ trend got us thinking… Why drag two amps to the show when you could take just one? The result is the OB1 Series of class A/B rack mountable bass heads which take care of this and much more besides. The key to the OB1’s unique sound is our footswitchable Blend circuit which adds a veneer of controllable gain and increased harmonic content to the upper registers of the input signal. The lower frequencies and clean signal are left alone, staying warm and clear just as they would be in a ‘bi-amped’ setup. Depending on where the Gain and Blend controls are set, the possibilities are limitless. Punch in the Blend control to achieve anything from a transparent clean boost, to all-out filthy grind, and everywhere in between. OB1-500 shares the same layout and 2U rack dimensions as the less powerful OB1-300, coupled to a full fat 500 Watt output section to move some serious air.