The Wilson Effects Overdrive is not just another tube screamer circuit. With a modified gain stage and tone stack the Overdrive gives you much more gain and much better sound than the original circuit and at a fraction of the price. Not only does it give you more gain but there are also some additional features that set this apart from your run of the mill tube screamer clone. Their is an added clipping switch that allows you to toggle between the original diode clipping of the circuit as well as LED clipping which provides a slightly louder punchier sound than the diodes. In addition to the clipping switch there is also a Fat switch that allows you to alter the tone stack yet again and add more bass to the overdrive. All of this and you still won't pay as much as a reissue would cost. The Overdrive is true bypass and is powered by an industry standard 2.1mm center negative power supply or 9v battery.