Tested By Andy Ellis
In today’s hype-filled world, companies rarely undersell a product, but that’s what Taylor Guitars is doing with their new K4 Equalizer. Yes, it’s a sweet-sounding EQ, but there’s more to it. Designed by pro-audio guru Rupert Neve, and boasting a studio-grade analog preamp and a fistful of handy features, the portable K4 offers many of the attributes of a recording console’s input strip. The single-channel K4 is designed to help you coax the best tones from an amplified acoustic guitar with minimum effort. To put the box through its paces, I tested it with a new Taylor 512CE sporting ES electronics, a CA Legacy with a Fishman Prefix Premium Blend mic-and-transducer system, a ’92 Taylor 512C with a Duncan MagMic soundhole pickup, and a Takamine ENV760S with a CTP-1 Cool Tube preamp.
The K4 has an intelligent layout, with all of its jacks on the back panel, and all the knobs and most of the buttons on the front. The thick aluminum case promises a lifetime of duty, and the wood trim on the top suggests the K4’s acoustic orientation. Thanks to its Neutrik combo jack-which accepts either a 1/4" phone, a 1/4" TRS, or an XLR plug—the K4 can accommodate active or passive, and high- or low-impedance input signals. Thus, you can plug in a guitar equipped with an onboard preamp system, a passive saddle or soundboard transducer, a magnetic soundhole pickup, or even just an onboard low-impedance dynamic mic. (The K4 is not a blender or outboard mixer, however. It processes one signal, so if you have a multiple-pickup system, you’ll need to blend their outputs before they get to the K4.) The preamp automatically adjusts to the type of input signal it receives—you do nothing but jack in.
The box has two outputs—a mic-level XLR out for feeding a mixer, and a 1/4" out for an acoustic amp. Connecting a TRS cable to the 1/4" out generates a balanced signal—perfect for retaining fidelity in long cable runs. A single knob controls the volume of both outs, which you can use simultaneously. There’s also a headphone jack with a separate Volume (and lots of gain), a Tuner out with a button to mute the main outputs (but not the headphones), and a button for phase-reversing the input and output signals to combat feedback onstage. Finally, a 3-way switch lets you dodge pesky ground loops.
The K4 arrived with a hip One Spot power adapter from Visual Sound, but the unit will work with any 3-15 volt DC source that has the correct polarity and current rating. Alternatively, you can run the K4 on batteries for up to ten hours. In battery mode, the green “on” LED turns red when the power drops below 3 volts. This power LED is the only visual feedback provided by the K4. When switching between different guitars and pickup systems, I found myself wishing for an input meter or a “signal present” LED.
The K4’s slick effects loop has a front-panel in/out button and a rear-panel pre- and post-EQ switch. This gives you the option to, say, add reverb to the equalized sound or compress your guitar before sculpting its timbre. Monitoring through headphones rather than the mains, however, I was surprised to discover that effects are audible only in the pre-EQ position. (According to Taylor, you can monitor post-EQ effects via headphones by plugging them into the main balanced outs.) The 1/4" TRS loop accepts both balanced and unbalanced signals, which means you can insert either stompboxes or rack gear.
At the heart of the K4 lies its potent yet straightforward tone-shaping circuitry. For starters, there’s a pair of active shelving EQs—a Low-EQ level knob with a 125Hz shelf, and a High-EQ knob with an 8kHz shelf.
Each control offers 10dB of boost or cut, and together they worked magic on all my test instruments. Typically, goosing both knobs a tad fattened up the bottom and enhanced note definition.
The parametric midrange EQ does the heavy lifting. Using a sweepable Frequency knob and Range Selection button, you can set the center frequency anywhere between 80Hz and 8kHz. A Q knob lets you adjust the bandwidth surrounding the center frequency, and a Level knob provides 10dB of boost or cut within this area. This flexible midrange EQ is useful for such precise tasks as accentuating pick attack or notching out a rumble near low G.
Compared to the passive tone controls of a vintage tube amp, the K4 wields shocking sonic power. Fortunately, it’s easy to master, and center detents in the Cut/Boost knobs let you return to an uncolored sound if you get lost. Using the K4, I was able to quickly refine my amplified tone, whether I was running a flat-top through studio monitors or a combo amp. If I needed to soften the bite of a saddle pickup, add shimmer to a magnetic pickup, clarify strummed chords, or surgically reduce feedback, the K4 was up to the task.
It isn’t cheap—you can get excellent, less expensive outboard EQ from Fishman, L.R. Baggs, and D-TAR—but there’s undeniable magic in Neve-designed circuits, and acoustic players who are serious about their amplified sound will appreciate the rich warmth of the K4’s preamp, EQ, and transformer-coupled inputs and outputs. When you realize you can bring some classic Neve voodoo to your next gig, suddenly the K4 seems like a bargain.