The Finch Electronics Cotton Candy is a mosfet clipping based overdrive circuit. Within it, the input and output buffers are driven by a new, old stock, bi-fet CA3240 op amp date stamped the 7th week of 1982. This specific op amp has a super high input impedence and is sure to not bog down any pickups you plug into it. It also contains a charge pump that allows you to run it either at 9 volts or 18 volts for better articulation and headroom, all off of a 9 volt supply. No need for an 18 volt power supply. It is true bypass and will make your tone not suck.