Source Audio ZIO Analog Front End + Boost
The goal in creating the ZIO Analog Front End + Boost was simple yet ambitious: “Make Everything Sound Better!” ZIO is an all-analog preamp/boost pedal that includes a choice of four distinct preamp circuits, each with up to +20dB of additional output boost. ZIO is Source Audio’s first all-analog effects pedal and designed in collaboration with Christopher Venter, the owner and sole engineer at SHOE Pedals.
ZIO is a deceptively flexible unit that can serve many different purposes at various places in your signal path. Use it at the front of your chain of effects to shape the rest of your outgoing tone, after your drive pedals as an overall tone sweetener or clean volume boost, or at the the end of your pedalboard to drive a long cable run or as a restorative device to recreate the sound of your guitar going directly into the input of your amplifier. You can also use the ZIO in your amp’s effects loop if you want to drive your power amp even harder, or to compensate for a level mismatch between two channels.
“The Better Box”
The word “ZIO” is an acronym for Impedance (“Z” is the electrical symbol for impedance), Input (“I”), and Output (“O”). The pedal is designed to take a guitar’s high impedance signal, sweeten the tone with any of its four preamp circuits, and output a strong, low impedance signal that won’t be altered by the buffered dry tones of effect pedals further down the signal chain. High fidelity, noise-free Burr-Brown op amps help give ZIO extreme clarity and responsive pick dynamics, while maintaining ideal body and warmth. ZIO has four distinct preamp circuits. JFET offers a completely transparent signal boost with zero coloring or distortion. LOW-CUT reduces “tubby” bottom-end for a tighter sound with added headroom. STUDIO finds inspiration from the time-honored “Pultec Trick,” a studio technique that adds clarity by cutting the “mud frequencies” and adding mid-range articulation. E-PLEX captures the focused and subtle grit of the preamps found in vintage Echoplex Tape Delay units. The ZIO’s TONE toggle offers three different levels of capacitance (or simulated cable length) to brighten or darken the tone.
Four distinct preamp circuits
The Zio delivers a quartet of unique preamp circuits to perfectly dial in your sound:
JFET: This circuit has a remarkably similar response to a low-distortion clean tube amp input. Designed to function transparently, the JFET boosts without adding in any unpleasant harsh qualities.
Low-cut: Engineered to temper the “low-lows” that threaten to cause a rumble in your mix, this mode strictly impacts the low end with no changes to the low midrange. The Low-cut works great on guitars, bass, and synths to improve headroom and clean up your mix.
Studio: This mode takes inspiration from the famous “pultec trick” of the ’50s to provide greater clarity to your sound. Studio mode delivers a distinct low-mid cut, slight upper-midrange boost, and a subtle highpass filter that produces a clean and natural sound that allows your guitar or bass to shine in your mix.
E-plex: Modeled on the famous ’70s tape echo, this setting has all the vintage vibe of the original unit’s preamp. As a classic FET buffer/boost tone, the E-plex provides a slightly dirty, midrange-focused boost that is dripping with analog character.
Cable Length is Tone
When we connect a cable to the output of a passive guitar pickup, it does more than just pass signal on to the next device. Many guitarists will be familiar with the idea of different cables imparting a specific tonal quality. This is because cables have a property called capacitance, which increases with the length of the cable. This capacitance interacts with passive pickups and guitar wiring, to create a resonant filter and the higher the capacitance of the cable, the lower the cut-off of the resonant frequency. The three toggle positions replicate different lengths of cable. Select the BRIGHT position to introduce a low capacitive load and the most treble content. Selecting MED provides additional capacitance and produces the effect of a medium length of cable (roughly 15 feet). Selecting the DARK mode gives the effect of a longer cable or coils cable and is useful for taming excessive brightness or providing a stylistic voicing choice
A Higher Quality Op Amp
After bench-testing some classic op-amps used in overdrive, distortion, and boost stompboxes such as the ubiquitous TL072 and about half a dozen popular op-amp chips spanning back to the 1970s, we selected the Burr Brown for its pure tonality, dynamic range, frequency response, and overall feel. While other chips had certain properties such as sounding “too bright”, “too thin”, “too distorted”, etc., the unmatched transparency and headroom of this 14-legged Burr Brown OPA chip was the perfect match for the ZIO’s mission of delivering you your own tone, but better.
Features and Specifications:
- Circuit knob with four distinct preamp circuits: JFET (transparent, flat frequency curve), LOW-CUT (cuts lows without affecting mid to high frequencies), STUDIO (replicates “Pultec Trick” equalization), E-PLEX (inspired by the preamp in an vintage Echoplex Tape Delay unit)
- High quality components and Burr Brown JFET op-amps
- Output control with up to +20dB of signal boost
- 3-way Tone toggle switch with bright/medium/dark cable capacitance voicing
- 2-way Footswitch Action toggle switch (with always-on “Mute” option)
- Extra Tuner/Line Output
- True Bypass
- Input Impedance: 1 Mega Ohm (1 MΩ)
- Output Impedance: 150 Ohm (150 Ω)
- Power Consumption: 9V DC center negative @ 20mA
- Brushed anodized aluminum housing
- Dimensions: L: 10.5cm x W: 6cm x H: 5.65cm (including knobs)