Check the listing for details. Electro-Harmonix Q-Tron+ Envelope Follower. Condition: New. Listed at 192.30 USD. Electro-Harmonix Q-Tron+ Envelope Follower The Electro-Harmonix Q-Tron+ Envelope Follower. FREE shipping anywhere in the USA! The EHX Q-Tron+ Envelope Follower adds the power of a built-in Effects Loop and Attack Response Control to the proven platform of the original Q-Tron. The unique Effects Loop lets the musician place a sound effect between the Q-Tron+'s envelope detection circuitry and filter sections without changing the envelope drive. The rich harmonics created by a distortion pedal can now be processed by the filter without degradation to the signal's natural envelope and with full dynamic response. Electro-Harmonix claims that plugging other devices, such as the Electric Mistress Flanger or Deluxe Memory Man Analog Delay into the Q-Tron+ Effects Loop creates an array of exotic new sounds. The Attack Response Control lets the player select between a slow, smooth, vowel-like attack and the fast, snaked response of the original Q-Tron. Features:- True bypass - Dedicated effects loop allows you to place any effect or pedal board into the loop - FX send and return without changing the envelope drive - Selectable low pass, band pass and high pass filters - Resonant peak control to adjust the filter's Q from subtle to dramatic - Response switch changes the reaction time of envelope follower from fast to slow - Switchable hi or lo frequency sweep ranges - Adjustable gain knob and boost switch - Sweep direction switch for up or down filter sweeps - Tough and compact die-cast chassis - 24DC-100 power supply included Video courtesy of Electro-Harmonix