Tag: Boost

Source Audio ZIO Review

Source Audio nicknamed the new ZIO pedal “the Better Box,” which is a fair summation of what this thing will do for your tone. Purists may rant endlessly about the virtues of plugging straight into an amp. But many legendary players understood that a little extra “hot” between guitar and amp can add up to magic. From Jimmy Page’s Echoplex preamp to Brian May’s Rangemaster to Angus Young’s Schaffer-Vega wireless system, a lot of signature sounds have been shaped with a little extra kick—and often from unexpected sources that are something other than simple boosts. Source Audio’s first all-analog pedal is more than a conventional booster, too. And, to some degree, it celebrates these alternate paths to boosting tone.


Designed in collaboration with Christopher Ventner of SHOE Pedals, ZIO is short for Impedance (“Z” in electro-speak), Input, and Output, which hints at the front-to-back thinking behind the design. The pedal’s input impedance is calculated to optimize the signal from a traditional high-impedance guitar pickup and send it down the line as a sweetened low-impedance version of itself. In doing so, ZIO helps your signal survive long chains of pedals and cable runs. Four selectable modes each offer up to +20 dB of gain and three levels of cable-mimicking capacitance to subtly brighten or darken your tone as desired.

All recordings using a Novo Serus J guitar set to the bridge pickup (an Amalfitano P-90), into a Friedman Mini Dirty Shirley set to clean and 1×12 cab. Zio pedal set at 50% output, Tone on Bright.

  • 0:00 – ZIO pedal off.
  • 0:08 – ZIO on, JFET setting.
  • 0:44 – Change to Sudio setting.
  • 1:04 – Change to E-Plex setting.
  • 1:24 – Pedal off again.

Got Some Front

Though its methods for tone shaping might seem slightly esoteric on the surface, ZIO is easy to use. The knobs are a single control for output level and a 4-position rotary switch, dubbed circuit, which selects the preamp voicing. The JFET mode uses Burr-Brown op amps to generate a transparent, low-distortion boost, mimicking the response of a clean tube amp input. Low-cut mode reduces frequencies that can cause mud and rumble, lending more presence. Studio mode successfully replicates the effect of using a Pultec compressor to cut muddy lower-mids and enhance presence. The E-Plex mode, meanwhile, replicates the rich, clear, and just slightly colored sound of a vintage Echoplex preamp.

Source Audio is mindful of the fact that a long cable’s capacitance is an essential part of some players’ overall sonic brew, and that a booster/line-driver in front of the chain can negate the capacitance effect. So ZIO includes a tone toggle that offers three levels of cable-capacitance emulation. Bright represents a low-capacitance load and the brightest tone—as you might hear from a very short, high-quality cable. Med approximates a 15-foot cable and softens highs just a bit. Dark achieves the mellowing effect of longer or coiled cables.

A 2-position mini-toggle to the right is specifically tailored for players that will keep ZIO on at all times and allows the user to configure the footswitch as a mute function in place of the traditional off setting. That means one of the two outputs on the left side of the pedal can feed a tuner running independent of the signal chain or deliver a line-level signal to any amp, console, interface, or input that you want to keep live while muting the main output. Nine-volt DC power feeds the ZIO, with a center-negative input on the crown. It’s all housed in a rugged brushed-aluminum enclosure that’s not quite mini-pedal small but compact at 4″ x 2.3″ x 2.2″ tall (including the knobs).

I fast fell I love with ZIO’s variety of boost tones and easy integration into my pedalboard.

All Lined Up

I fast fell in love with ZIO’s variety of boost tones and easy integration into my pedalboard. It flat-out sounds fantastic. Some players will no doubt consider ZIO pricey for a booster pedal with a few extra bells and whistles. But the enhanced tones will be well worth it for many guitarists, even if they only ever use one circuit mode.

That said, switching between the circuits is half the fun. And at times I fantasized about a rig based on two ZIO pedals: One that I could use as a transparent always-on line driver and tone juicer, and another as a proper boost. Used in the latter application, ZIO made my tweed-style combo bite and break up a lot more readily. It was also secret sauce for a Friedman Mini Dirty Shirley, making its Plexi-style crunch and lead tones extra delectable. While all four preamp-emulating modes proved effective—and I could certainly find many useful applications for each—I really fell for the Pultec-inspired studio mode. It’s sweet, juicy, clear, and articulate, and it simply makes everything more luscious. It can also offer a playful dose of extra drive when you crank the output past 11 o’clock. It sounds fantastic as an amp-input driver in this setting. The tone switch settings are pretty subtle, but that’s the idea: You use it to fine tune the feel and character of the signal once you’ve dialed in the other functions to near-perfection.

The Verdict

Boosts are often one-trick ponies. But Source Audio and Christopher Ventner’s sly and very smart selection of features make ZIO a whale of a tone enhancing machine—and a sneakily versatile one at that. Yes, the ZIO is a simple device in principle, but it does what it does exceptionally well. And while many players will regard the tone switch and switch modes as minor bonus features, I suspect they will prove invaluable to many exacting tone crafters and super-functional in some rigs. For me, at least, they help make ZIO one of the tastiest boost pedals I’ve tried in quite some time.

Stacking Effects? Keep a Beginner’s Mind

Years ago, while on a meditation retreat in the mountains of Ojai, California, I was reflecting on one of my favorite sayings by Shunryu Suzuki (from his book Zen Mind, Beginner’s Mind): “In the beginner’s mind there are many possibilities, but in the expert’s there are few.” It was early in the morning, and as the soft blue light of dawn broke over the snow-dusted mountain tops, I had the profound realization of just how narrowly I was choosing to live my life because of my habits and how I was continually and slavishly refining them through my actions. I allowed myself to imagine and feel what life would be like if I let go of ingrained beliefs, and stood squarely in the warm, bright light of new possibilities.


I’d like to invite you to journey with me by exploring the importance of challenging your musical habits and see how to set the stage for inspiration, breakthroughs, and happy accidents.

Before stompboxes were common, there was no need for effects loops in amps. All effects (wahs, fuzzes, phasers, flangers, delays, reverbs) occurred before the amp, sometimes producing gloriously messy results.

There’s no better place to start than by focusing on effects (overdrives, delays, reverbs, wahs, tremolos, etc.) and the order in which they are arranged. Regardless of whether they reside on the floor, in racks, or inside your DAW, let’s shake things up, break our own rules, and see what remains of our old views. I believe this is how we truly gain wisdom. The Dojo is now open.

Look at your pedalboard. Most likely you have a wah, overdrives or other fuzz/distortions, and then effects like chorus, phaser/flanger, followed by a delay, and finally a reverb. If you’re using a multi-effects unit, like a Line 6 HX ($649 street) or similar, you have multiples of all these categories to choose from and the added flexibility to rearrange the signal flow without the hassle of unplugging and moving pedals around on your pedalboard. The options are even greater if you’re using a DAW and plug-ins.

When playing through Fender Princeton/Vibrolux-type combo amps that have both tremolo and reverb functions [Photo 1], the reverb will sound like it is last in the signal chain, although tremolo is actually last. Using real or virtual pedals to experiment, we can evoke that sound and add tremolo after our reverb.

On my end, I’m using EarthQuaker Devices’ Night Wire, a harmonic tremolo ($199 street), and their Afterneath reverb ($199 street) [Photo 2]. Place your tremolo effect after the reverb, grab your guitar and listen to the difference versus an amp. I love the way this sounds. It’s super vintage, retro, and lo-fi. If you have the ability to change the wave shape of the tremolo from sine to triangle or square, do that and keep playing. Record your experiments so you can note how things change without the distraction of a guitar in your hands.

Next, add a delay to the chain before the tremolo. Experiment with adjusting delay times manually, or, if available, use your tap tempo switch and dial up eighth, dotted-eighth, quarter notes, and subdivisions. You can also get some great textures by altering the wet/dry mix and adjusting the feedback as well. Depending on your delay, you might also have multiple types to choose from: maybe an old tape-delay setting (with lots of wow and flutter), or a bucket brigade, or even a reverse delay. Feeling creative yet? And remember, all of this applies to the virtual world of DAWs as well.

Here’s another one to try, and, again, it has vintage roots. Before stompboxes were common, there was no need for effects loops in amps. All effects (wahs, fuzzes, phasers, flangers, delays, reverbs) occurred before the amp, sometimes producing gloriously messy results. You can pay homage to this era and add a new twist by connecting a phaser followed immediately by a flanger. For this, I’m using Big Joe’s Phaser ($159 street) going into Earthquaker Devices’ Pyramids flanger ($299 street) [Photo. 3].

I like to adjust the rate, feedback, and depth settings on each unit with oppositional values relative to each other. For example, on the phaser I’ve set a fast rate, low depth and feedback, and 100 percent wet mix. I’ve inverted those values on the flanger with a slow rate, heavy depth, above average feedback, and 100 percent wet mix. I encourage you to spend a lot of time tweaking these parameters, as there are plenty of possibilities. Just be mindful of your feedback values since you have one unit cascading into the next. Finally, to bring a little danger to the equation, add a wah pedal. Hit record and then listen to how things change.

Most importantly, have fun and give yourself permission to make some crazy sounds! Next time I will explore adding this approach to groups of instruments, like synths, guitars, and drums, and entire sections of a mix. Until then, keep striving for your beginner’s mind and break your own rules. Namaste.