I dig this one so much that I built two of them in case someone else wanted one. It's an exact clone of the Mutron III but also includes a few very useful mods. Anyone that has owned the original knows that its gain sets the sensitivity but it changes the output level, so I added an output level so that you have complete control over that and the additional sensitivity control allows you to have better control of how hard you drive the envelope. I also added a filter switch that switches between the stock filter and a 'moog' filter that has a less spikey peak as the filter sweeps downward. There's also an extra LED indicator that shows when the filter is being triggered. It's true bypass and runs on a standard Boss or OneSpot style 9 volt adapter. It's mounted in a 1590BB sized enclosure so it's a lot smaller than the original to save on pedal board space.