NUX NOD-2 overdrive pedal TUBE MAN MKII OVERDRIVEMini Core Series Genuine Tube like sound that makes it more than your average Tube Screamer! More gain ! That was the overall goal. If youre not playing through a real tube amp, cranked for overdrive, its difficult to get genuine tube overdrive sound. The original Tube Screamer pedals used an OP AMP system, a basic circuitry that became popular for its perfect amp attributes. It had no distortion so it had to be overdriven or distorted by re shaping