I've written in these pages before about the sometimes-maligned, always-underestimated EQ pedal. Often ignored or written off by guitarists as a mundane utility item, or a sonic Band-Aid of sorts for a fundamentally flawed tonal foundation, the lowly EQ pedal is a powerful, yet frequently overlooked generator of great tones. In addition to sprucing up a less-than-stellar base sound or compensating for unexpected stage or monitoring anomalies at gig time, a good equalizer can help a solo cut through the mix, breathe new life into an old drive or distortion pedal, and help create rich textures that would otherwise not be possible. These are just a few examples that illustrate the great creative potential of the EQ pedal.
Most EQs for guitar are of the simple graphic variety, with tiny sliders that boost or cut specific, pre-set frequencies. These can be excellent, and are all that's needed for many players, but for guitarists who really want to get into deep, surgical tone shaping, a parametric EQ is ideal. Parametric EQs are familiar to anyone who knows their way around a recording studio, and are the primary sonic carving knife of most professional recording engineers. The advantages of a parametric or semi-parametric EQ are significant, as they offer much more precise control over amplitude, bandwidth, and center frequency than other varieties. Here is a grip of our favorite parametric-style EQ's for guitarists who want to bring the power of these potent tone shapers to their pedalboards.
Boss PQ-4
This sadly discontinued gem from Boss is an excellent early example of a semi-parametric EQ circuit designed for the pedalboard. Manufactured from '91–'97, the PQ-4 was not a huge hit during its production run, likely being overshadowed by Boss's stalwart GE-7 graphic EQ. Since then it has gained something of a reputation for versatility, quiet operation, and the very musical way in which it pairs with dirt pedals. It offers broader shelving equalization for low frequencies and high presence, while mid frequencies are variable between 100Hz and 1.6kHz, and the high range covers from 500 Hz to 8kHz. The selected frequency range can be boost or cut a hefty 18dB, and overall level can also be boost or cut by the same amount, giving the PQ-4 a lot of power to slice and dice a guitar sound. The best thing about the PQ-4 is its smooth, quiet, musical personality, which avoids the harsh artificiality of lesser EQs, and makes this pedal ideal for getting the most out of overdrive and distortion boxes. The Boss PQ-4 is not uncommon to find on the used market for between 80 and 120 dollars.
SansAmp Para Driver
The Para Driver is an incredibly useful tone-shaping device, combining elements of guitar pedal, preamp, DI, and equalizer into a versatile tool that is as at home on a pedalboard as it is in a recording studio. It features lots of options for warming up, dirtying up, and routing a guitar sound, whether it's going to a tube amp or direct into a console, but the best feature is the EQ section. Treble and bass frequencies are fixed, but the midrange is a sweepable, semi-parametric circuit that can hone in on frequencies ranging from 160Hz up to 3kHz, covering most of the crucial frequencies for electric guitar. The SansAmp Para Driver is invaluable for recording, in particular, but I've found it just as useful as a regular component of my pedalboard, and it works beautifully after dirt pedals for adding extra bite, oomph, honk, sparkle, or whatever kind of enhancement might be desired.
T.C. Electronic DPE Dual Parametric Equalizer
The DPE is a rare bird, and a weird bird as well, but it's guitar sculpting powers are a thing of legend. Reportedly used by The Edge, David Gilmour, and Adrian Legg, this discontinued box of vintage Danish sonic wizardry boasts a huge range and precision carving capabilities. It features two bands of EQ, one covering the 20Hz to 2kHz range, and one covering 100Hz to 10kHz. Bandwidth knobs for each allow you to adjust how broad a frequency range it effects, from a wide one-octave band to a super narrow one-tenth octave. The selected ranges can be cut or boosted 16dB. It also features a fixed high treble control for boosting or taming overall brilliance, and an overall output gain knob. The DPE is so powerful that it's nearly overkill for electric guitar, and its learning curve is fairly steep, but it's a spectacular sounding equalizer for the truly dedicated tone tweaker. Sellers often ask preposterous prices (like 400 to 600 dollars) for the DPE on the used market , but buyers that are willing to shop around and wait for a more reasonable deal can often get one for under 200 bucks.
BYOC Parametric EQ
For relatively experienced DIY'ers looking to save some dough on a sweet sounding and very flexible parametric EQ for the pedalboard, BYOC's Parametric EQ kit is a superb solution. It features a three-band circuit, which covers from 33Hz to 11kHz overall (making it great for bass and other instruments, as well as guitar), with each band having a dedicated Q control for adjusting bandwidth, and +/-12dB gain control for boosting and cutting. An overall level control offers more than 30dB of boost for walloping the front end of a tube amp, and it has more than enough headroom for most instrument signals. At around 120 bucks, the BYOC Parametric EQ kit is a real bargain, but the build itself is somewhat involved, so it's not a good choice for virgin solder monkeys.
Empress Effects ParaEq w/ Boost
I've sung the praises of the Empress Effects' ParaEq in previous issues, but that's because it rules. It's likely the most comprehensive and powerful parametric EQ circuit ever stuffed inside a compact stompbox enclosure, besting even much more expensive rack equalizers in sound quality and versatility. Its active circuit can boost or cut 15dB in each of its three frequency bands, and it offers a Q control switch for each. Clarity and headroom are best-in-class, thanks to an 1v power option and an input pad for hotter signals, and the ParaEq operates very quietly, even when the high frequencies are boosted drastically. 30dB of overall output and a dedicated boost footswitch make it an excellent clean boost as well. At $249, the Empress Effects ParaEq is a total steal for studio quality EQ on a working guitarist's budget.