Like many Source Audio designs, the audio is super high-quality. The heart of the pedal is 10 fully adjustable frequency bands-ranging from 31 Hz to 16 kHz-that each enable 18 dB of boost or cut. The new version effectively doubles the fun while streamlining the interface, adding stereo inputs and outputs and a wealth of bonus features, including a hidden tuner. Rarely content to sit still, Source Audio has reimagined the Programmable EQ as the EQ2. But in general it enjoyed a fraction of the recognition enjoyed by the company's excellent reverb, delay, or modulation units. It has high-profile fans in David Gilmour and John Mayer, among others. So it might come as a surprise that the original DSP-driven Source Audio Programmable EQ, released in 2011, is among the company's best-selling products. Good EQ pedals are very powerful tools, if not the most glamorous.