Source Audio ZIO Analog Front End + Boost review

Designed by Source Audio to “make everything sound better”, the ZIO, the company’s first all-analogue pedal, is a preamp/boost pedal that’s capable of up to 20dB of boost via a choice of four different preamp circuits to colour the sound. 

On top of that, it acts as a buffer and has a Tone switch that offers three different levels of capacitance to simulate cable length, allowing you to make your tone brighter or darker. 

The pedal has two outputs, the second one being available as a line output or to keep a tuner permanently connected on your pedalboard without being in the main signal chain. The footswitch can be used as a normal bypass or it can be set to mute the main output – which is useful for some silent tuning.

The JFET is the most transparent of the preamp circuits and will retain your core tone but make it louder and more robust. Unity gain on the pedal is at about 10 o’clock, allowing plenty of leeway to dial in a targeted boost. It’s great if you want pure amp distortion without recourse to a drive pedal, and at max will fire up the cleanest guitar amp.

You may wish to use the Low-Cut option, though, because that can keep things really tight, basically rolling off any really low-end from the signal and especially useful on gainier sounds.

The Studio option (based on Pultec EQ settings used in studios) is a real tone‑sweetener that combines a mild lower-mid scoop to reduce muddiness with a higher boost for clarity and articulation.

Finally, the E-Plex setting mimics the old favourite Echoplex preamp and can add a whisper of dirt and a focused midrange with some top rolled off. 

The obvious use for the ZIO is at the front end of your signal chain – a job it does admirably – but it also works well as the last pedal before an amp or as a sweetener and an extra push for your drive pedals. Overall, it’s a tiny box with big functionality.

Specs

• PRICE: $/£199
• ORIGIN: China
• TYPE: Preamp and boost pedal
• FEATURES: True Bypass
• CONTROLS: Output, Circuit switch (JFET, Low Cut, Studio, E-Plex), Tone switch (Bright/Medium/Dark), Bypass/Mute switch, Bypass footswitch
• CONNECTIONS: Standard input, standard outputs
  (Main and Tuner/Line Out)
• POWER: 9V-18V DC adaptor
  20 mA (not supplied)
• DIMENSIONS: 66 (w) x 104 (d) x 55mm (h)
• CONTACT: Source Audio