Check the listing for details. Electro-Harmonix XO Micro Q-Tron Envelope Filter Guitar Effects Pedal QTron. Condition: New. Listed at 112.50 USD. Electro-Harmonix XO Micro Q-Tron Envelope Filter Guitar Effects Pedal QTron At Music Store Live we're all musicians like you, and we know how hard it can be to afford all the gear that you want and need. We encourage you to make us an offer. Often times, you'll be pleasantly surprised! Additionally, don't hesitate to contact us regarding financing options. We'll do everything we can to help get that next piece of gear into your hands. The Micro Q-Tron is a smooth envelope filter with a funky wah-wah tone. The filter is controlled by its internal envelope follower, analyzing the volume of your notes and the dynamics of your playing to directly sweep the filter's center or cutoff frequency. A stronger attack or louder note will produce a wider frequency sweep while softer playing produces more subtle effects. Use the Q control to make the effect more dramatic. Features True bypass Drive control sets sensitivity and filter sweep range Selectable low pass, band pass or high pass filters Q control sets the filter's bandwidth from smooth to funky Tough and compact die-cast chassis 9-volt battery included Optional 96DC-200BI power supply available