Dual bias controls let you complete most tube swaps in less than a minute. The precision, hand-built, single-channel THD Flexi-50 50W/20W Class AB Amplifier Head can operate loaded with almost any preamp and power tubes in any combination. It's the only amplifier you need to own. Whether you strive for English overdrive, California clean, or Texas punch, this master-class head can deliver. It also boasts a heady 50W Class-AB operation, footswitchable overdrive/boost, and footswitchable master volume control. Its consistently overbuilt and pristine circuitry ensures dramatic touch sensitivity even at the highest overdrive settings. Its incredible flexibility (the reason it's named Flexi-50) delivers all the sounds and tones you could possibly desire, from vintage purr to modern, high-gain roar. The Flexi50 also has a Lo/Hi input switch; Volume, Treble, Middle, Bass, Master, and Cut knobs; Boost section w/separate Gain & Tone knobs, and wattage select switch (50W/20W).