The Ibanez AF 201 Auto Filter is a relatively scarce effect pedal from Japanese giant Ibanez and manufactured by their business partner, Maxon. The AF 201 falls into ‘well-kept secret’ territory and is relatively hard to find on the vintage market. Its design belongs to the same relatively short‑lived ‘0’ series pedals as Ibanez’s most famous pedal, the TS‑808 Tube Screamer, characterised by the distinctive square footswitch. The AF 201 is an envelope filter producing various auto‑wah sounds loosely based on the pioneering Musitronics Mu‑Tron III. The auto‑generated wah‑type effects were popular in the late 1970s and early 1980s, particularly with funk and rhythm‑centric beats – it certainly produces very evocative sounds that are very much of its time. The AF 201 is probably less familiar than competing models from Boss (Touch Wah/T Wah), Electro-Harmonix (Zipper/Doctor Q) and MXR (Envelope Filter). Other than the company’s Graphic Equaliser pedals (GE 601/GE9), the AF 201 is unusual in the Ibanez line up in that there are no control knobs to play with, only sliders and switches. The AF 201 was superseded by the Ibanez AF9 from c.1982 alongside a Maxon‑branded, AF‑9 version. To‑date, Ibanez has not sought to reissue the Auto Filter, making them quite pricey on the vintage market.