Electro-Harmonix Q-TRON PLUS Envelope Filter with Effects LoopThe classic Q Tron gets even funkier. Same design as the original EHX Q Tron, the Electro Harmonix Q Tron Plus Envelope Filter with Effects Loop gives the musician the ability to place an additional effect, or chain of effects between the EHX Q Tron Pluss preamp and filter section without changing the envelope drive. This is particularly important with most distortion devices, as most all do not have much of an amplitude envelope. The FX loop will