Sustain is one of the strangest Overdrives that I've ever heard built into an Amp. Built like a Tank and will probably run for 40+ years w/out maintenance. The IC 100 Amp's were made famous by T-Rex, Pink Floyd, The Clash and Daniel Ash(Bauhaus, Love & Rockets). The Amp has 2 Channels: 1 Super-Clean and a nasty Bright(Clean) Channel w/a Sustain switch. It plays well w/pedals as well the Amp has a Stage/Studio Volume Attenuator which is impressive for the '70s. Great Glam, Post-Punk Amp that will roar over the volume of a Band.