See the video review of the Radial Tonebone PZ Pre

Radial is known for its very well designed and rugged sound reinforcement accessories, most notably DI boxes. Recently, though, the Canadian company has branched out into the crowded guitar stompbox market with the Tonebone series. And with the Tonebone BB-Pre, it has filled a niche for the performing acoustic guitarist—or players of just about any other acoustic stringed instrument—by offering a feature-rich preamp/DI/EQ packed with thoughtful details and options.

PROFESSIONAL STANDARD

If you have limited experience with stand-alone preamps, the PZ-Pre’s three rows of knobs and footswitches may look a little daunting at first. Eight dials lined across the top of the unit control a three-band EQ, boost level, a notch filter, and input level controls for each of the two channels. Four small switches just below the array of dials activate a phase switch (for controlling feedback), enable the boost and effects loop, activate a notch filter, and switch on a low-cut filter for additional feedback control. The bottom three footswitches mute the unit for tuning or instrument changes; activate the boost channel, effects loop or both; and toggle between the two channels.

The back of the unit features a total of five outputs. There are two XLR connectors—one before the EQ section and one after—so that you can send both signals to the mixing desk, or one to the monitor mix, without the need for separate DI boxes. One of the ¼-inch output jacks is intended for connecting with onstage amplification while a tuner can be connected to the second.

The preamp inputs are followed by an EQ section that requires some study in order to understand the full extent of its powers. While the Bass and High frequency sections work more or less conventionally, the unit’s mid-range uses a more sophisticated, semi-parametric control set that enables cut or boost of a mid-range frequency using a dedicated cut/boost knob. The concept can be slightly alien at first, but it enables a precise, almost surgical control over the sonic response of your amplified acoustic instrument that will help you adapt to any performance situation.

PERFORMANCE TESTING

To better test the PZ-Pre’s capabilities in a performance situation, I set up my PA and plugged a piezo-equipped Gibson J-200 into one of the Radial’s two ¼-inch input jacks that can be used individually or blended for simultaneous input from two sources. Each channel has a volume pot and a switch that activates a buffered, Class A circuit specially designed for the low output and high impedance of passive piezo-electric pickups.

The piezo pickup on the Gibson came to life when I switched on the buffer circuit, and the preamp circuit delivered as much gain as I needed without a hint of distortion. When the piezo buffer is not activated, the input is perfectly matched for input from an instrument with an onboard preamp. And when you need just a little more oomph for a solo, you can stomp on the Boost switch and add up to an extra 8 dB of programmable, clean gain.

Having found an appropriate signal level, I decided to fine-tune the output via the EQ section.

One quibble I had was that the semi-parametric controls are not marked with the specific frequency values, making it difficult to know exactly which frequencies were problem areas. But with a few minutes of knob twiddling, I dialed in a pleasant, warm tone for the J-200 that captured many of that guitar’s signature jumbo and maple sounds.

Eager to see how the EQ and filters would respond at the feedback threshold, I boosted the output of the PA speakers. and was able to cut the rumbling lows easily with the low-cut switch but still had troubles with resonance on my low G note. So I switched the notch filter to the Deep setting and adjusted the mid frequency until the feedback disappeared. While the rumbling abated, the Deep notch seemed to compress the tone to an extreme degree, so I switched back to Normal setting, which kept the feedback at bay but restored some body back into the overall sound.

The Tonebone responded well to a variety of playing styles. A quick run-through of Libba Cotten’s “Freight Train” plucked with my fingers elicited a warm yet focused sound. And as I flatpicked a bit of the “Sailor’s Hornpipe,” the notes flew from the speakers fast and bright—requiring just a small reduction of the high frequencies to tame the clackity sounds imparted by the piezo pickups.

THE WRAP

The PZ-Pre is a thoroughly professional, high-quality piece of sound-reinforcement gear, jam-packed with features that, once mastered, provide amazing control over your tone and sound in performance situations. Given the impressive capabilities of the feedback abatement tools and the EQ, the PZ-Pre gives the gigging guitarist who plays a wide variety of rooms the flexibility to adapt to almost any performance situation—no matter how limiting the PA or acoustic properties of the room. And with top-quality construction that calls to mind a small tank, it’s a fair bet this pedal will remain an indispensable, long-term companion to any acoustic guitarist seeking greater control over their amplified tones.