Electro-Harmonix Q-Tron+ Envelope Filter EHX's flagship envelope filter - the Q-Tron+ with built-in effects loop. Six knobs (Mode, Response, Range, Peak, Gain, Boost), three toggle switches (LP/BP/HP/MIX filter mode, Fast/Slow sweep, Overload on/off), plus a dedicated FX Send/Return loop so you can insert other effects into the filter chain. Made in NYC, USA. This is the full-size Q-Tron+ (not the Micro or Nano version) - the one with the effects loop and all the extra controls that the smaller versions don't have. Currently $188 new. Bench-tested - every function verified: - Powers on cleanly via 24V DC supply (IMPORTANT: this pedal requires 24V DC center-negative, NOT standard 9V) - LED illuminates correctly - Footswitch engages and bypasses properly - All six knobs turn smoothly - no scratchiness, no dead spots - All three toggle switches click into position firmly - Filter sweep responds to pick dynamics across all four modes (LP, BP, HP, MIX) - Fast/Slow sweep toggle changes response speed as expected - Overload switch adds grit when engaged - FX Send and FX Return jacks on left side are physically clean What was NOT tested: - Effects loop (no second pedal patched through the FX Send/Return during bench test - jacks are physically clean and undamaged) Cosmetic condition: - Black graphic panel shows moderate surface wear - scuffing and paint rub around the footswitch area and edges, consistent with regular pedalboard use - Silver hammertone enclosure sides in good shape - normal gigging wear, no dents or cracks - All six original knobs present, straight, and secure - Velcro residue on bottom plate from previous pedalboard mounting - Footswitch firm and responsive - All screws present - Photos are of this exact unit - what you see is what you get What's included: - Electro-Harmonix Q-Tron+ pedal - That's it - no box, no manual, no power supply Power: 24V DC center-negative (NOT included, NOT standard 9V). The Q-Tron+ requires a dedicated 24V supply or a multi-output supply with a 24V tap. Do not use a 9V supply. Shipped weight: 1 lb 6.5 oz A note about used electronics: All electronics are tested. Any known issues are listed in the description above. Your item will not be sent DOA unless explicitly specified. Sometimes issues do arise in transit and can be caused by rough handling, old/brittle wiring, or a component failing under the rigors of shipping. Major issues are covered by insurance - that's why every package ships fully insured. Shipping: Listed shipping is for the continental 48 USA. International buyers - please send your full address so I can calculate exact shipping. Returns: This item is sold As-Described and cannot be returned unless it arrives in a condition different from how it was described or photographed. Returns must be in original, as-shipped condition with all original packaging.