Rather than recasting the circuit designs of iconic effects, Massachusetts-based Source Audio operates with a think-outside- the-box ethos that’s resulted in products like the motion-controlled Hot Hand. So it’s fitting that the company’s recently released Programmable EQ is more than just another run-of-the-mill tool for fiddling with frequencies.

The true bypass Programmable EQ is a 56-bit, DSP-driven, MIDI-capable digital equalizer pedal that enables you to save up to four footswitch-selectable settings and an output control that works as a clean boost. It’s easy to use too. With the unique Auto- Scroll feature that helps create a wealth of truly unique sounds that you can use onstage and in the studio, you can tailor your rig to different guitars or drastically shift your tone on the fly.

Path to Equalization
If you’ve used any kind of EQ pedal before, the Source Audio Programmable EQ’s basic layout is pretty easy to decipher. There are vertically oriented readouts for seven frequency bands—125, 250, 500, 1K, 2K, 4K, and 8K—that register incremental level changes from +/-18 dB boost or cut. Unlike most EQ pedals, there are no physical sliders. Instead, there’s a pair of band-select buttons on the pedal to get to the desired frequency, a big encoder knob to adjust the individual frequencies, and lights to indicate the levels. To quickly get all the bands to zero, you simply press both band-select buttons simultaneously. Just to the right of the encoder knob, you’ll find the luminous output knob, which has an LED indicator with variable brightness. It gives you up to 12 dB of clean boost and glows brighter the more you crank it up.

Hidden Agenda
The Programmable EQ also has a set of functions that Source Audio calls Backpage Parameters. One of the highlights of Backpage mode is the Octave Extension (denoted OE), a parameter well-suited for bass that enables you to manipulate an extra frequency of 62 Hz—one octave below 125 Hz—that can still be accessed after exiting Backpage mode. Another available parameter is Auto-Scroll (AE), which really takes the Programmable EQ to places few other stompbox EQs will go. This function enables you to continually scroll through all your saved settings, which can result in unique effects that are able to sound like a tremolo-meets-sequencer-meets-ring modulator, depending on how extreme your presets are. In some cases, the effect is reminiscent of the Roger Linn AdrenaLinn pedal (as heard on the intro to Green Day’s “Boulevard of Broken Dreams”). The effect might not be for everyone, but in the hands of a crafty sonic tinkerer, it can be the catalyst for some pretty unreal sounds. The speed of the Auto-Scroll function can be adjusted with another parameter called Switching Speed (SW), and the faster the setting, the more extreme the results.

Setting the Stage
I tested the Programmable EQ using a Music Man Axis Sport, a Pro Co Rat distortion pedal, and the clean channel of a Mesa/Boogie Lone Star Special with all of the tone controls set flat. Right off the bat, I was struck by the Programmable EQ’s transparency, which means you can finetune the sound of your rig to a room or a musical environment without sacrificing any character. And the 56-bit processing and 24-bit converters mean very quiet, hissfree operation.

Setting the Programmable EQ to a familiar V-curve with scooped mids gave my Mesa the feel of a blackface Fender when played clean, and a girthy metal tone when I threw the Rat into the mix—both sounds were fantastic for rhythm. For a thicker lead sound with more sustain, I simply boosted the mids. Once I saved these two settings, I ended up leaving the Programmable EQ on and switching between the two presets: this simple application alone gives your rig amazing flexibility. And even if you’re not looking to aggressively tweak EQ parameters, the Programmable EQ’s output knob can be set and saved for various levels of clean boost.

The Verdict
With a conventional slider-based EQ pedal, you’re most likely saddled with a single setting. And typically, those levels aren’t too easy to change on the fly. By allowing you to save up to four presets, the Programmable EQ becomes a much more formidable tool—particularly on stage where you want to maximize pedalboard real estate and the sonic range of your rig. And the range of EQ shifts that are possible with the Programmable EQ can radically transform your tone. But even if you favor subtle EQ shifts between lean rhythm parts or different passages, you can subtly or dramatically emphasize them with preset boost levels using the output control. What’s more, the sounds from the Auto-Scroll function can transform the pedal from a very practical tone-shifting tool to something much more bizarre, depending on how radically you set things up. At about 150 bucks, it’s a great way to get a lot more out of even the simplest guitar and amplifier rig—particularly if you like it simple. No matter how you slice it, this pedal puts a lot of sonic potential at your feet for the price.