The Amp Mode Boost is a Mosfet transistor boost and is the exact same circuit that is found in our best selling Prism preamp, as that mode is many musicians' favorite. Mosfet transistors are very popular types of transistors to use for boost circuits because they have many amp like" characteristics when they clip. Several very popular Mosfet boost circuits on the market have a very noticeable crackle when their boost knobs are rotated. Jackson Audio fixed this issue so it is perfectly silent when the boost knob is rotated. Use the Amp Mode as a preamp for your overall signal, a boost to push an overdrive pedal even further into saturation, or as a post overdrive boost to clarify and push your guitar forward in the mix! The Amp Mode features 9-18V operation, true bypass switching and a tiny footprint featuring top mounted jacks! The single boost control sets the overall boost for the Amp Mode. The Amp Mode is a true boost in that when the boost control is fully counter-clockwise, it doesn't boost your signal, it instead acts as a unity gain buffer that emboldens your guitars signal to prevent against tonal loss when using effect pedals or driving long cables."