Up for sale, a circa 1990s Electro-Harmonix QTron Envelope Controlled Filter big-box pedal in excellent condition and in perfect working order. A big box version of EHX’s beloved funk machine, this QTron delivers super phat filtered sounds with a broad frequency response to ensure compatibility with just about any instrument.

There’s nothing quite like experimenting with an envelope controlled filter: whether you end up in bubbling Bootsy Collins bass territory or quacked-out Jerry Garcia cocked wah soundscapes, there are arguably very few faster shortcuts to a slew of unique sounds. Controls include Peak, Gain, Range, and Mode (Low Pass, Band Pass, High Pass, and Mix BP/Dry) knobs, with two-way Drive (Up/Down Filter Sweep) and Range (“Hi” with overtones emphasized and “Lo” with vowel-like emphasis) switches. This QTron also features independent Wet and Dry outs.

The large polished aluminum enclosure shows some light surface wear, with clean graphics and original ridged pointer knobs.