Used Electro-Harmonix EHX Q-Tron Plus Envelope Filter Guitar Pedal QTron+ 1 Spot Pro Swell: This is the volume

Swell: This is the volume swell mode

With the VO-1

each effect in the PX-1 delivers the authentic sound and response of the pedal it's based on

Take on every playing situation with 23 guitar amps and nine bass amps

Used Electro-Harmonix EHX Q-Tron Plus Envelope Filter Guitar Pedal QTron+ 1 Spot Pro Swell: This is the volumeMint, all original packaging, as new Includes U. S. Version Power Supply Same design as the original Q Tron but with extremely useful Effects Loop and an Attack Response Switch. The Effects Loop gives the musician the ability to place an additional effect, or chain of effects between the Q Tron Plus's preamp and filter section without changing the envelope drive. This is particularly important with most distortion devices, as most all do not have much