Source Audio’s New C4 Synth Is A Modular Synth In A Guitar Pedal

SYNTH ANATOMY uses affiliation & partner programs (big red buttons) to finance a part of the activity. If you use these, you support the website. Thanks! 

The synthetic sounds conquer the guitar world. After the presentation of the Boss SY-1 last week, Source Audio from the UK today announced the release of the C4 Synth pedal. It’s a four-voiced Synthesizer pedal for guitar/bass that features all the functions you know from a modular Synthesizer inside a compact & easy-to-use pedal.

It’s impressive to see how synth pedals evolve in the past years if you compare especially the C4 pedal with products from the past. It features six dynamic synth effects (presets) with unprecedented tracking abilities and lightning-fast response.


Source Audio C4 Synth

Full Customization With The Neuro Editor

If you want to look beyond the six onboard effects presets, Source Audio ships the pedal with the Neuro editor (desktop/mobile) that let you choose from over 120 presets (1000+ in a month) or design own sounds with the 4-voice synthesis engine. Inside the Neuro editor, you can work with:

  • 3 Types of Oscillators: Mix and match any of the C4’s three oscillator wave shapes for pure synthesizer tones. Choose from sine, square, and saw shaped oscillators.
  • 11 Envelope Followers: Select from a comprehensive collection of envelope followers with adjustable attack/decay as well as ADSR triggering envelopes.
  • 25 Filter Effects: Choose from a huge collection of filters, controllable with an envelope follower or independently modulating LFOs.
  • Distortion, tremolo, pitch shifting, intelligent harmonization, FM synthesis,
  • 14 Different LFO Wave Shapes: Use LFO (Low-Frequency Oscillators) to control the modulation of filter, vibrato, or tremolo effects. Choose from eight different LFO wave shapes, including sine, square, sample and hold, sawtooth, and more.
  • Two Programmable 16-Step Sequencers: Run two simultaneous sequencer patterns. Choose from several preprogrammed sequencer patterns or create custom patterns.

Source Audio C4 Neuro Editor

Once connected, musicians can easily browse presets on the pedal for testing. Favorite presets can then be saved with a single click to one of C4’s six toggle switch positions or 128 MIDI accessible positions. It’s a fun process that allows users to create the perfect synth pedal for their needs. Sounds very promising in my opinion.

Straight-Forward Design Interface

On the pedal surface, the user has does not lose itself in a deep menu but only needs to use 4 knobs (two of the knobs are dual-function). They act as Input Level, Envelope Sensitivity, Wet/Dry mix, and two knobs labeled “Control 1” and “Control 2” that adjust different parameters depending on the preset. More info: the pedal also includes powerful 56-bit signal processing, a compact anodized aluminum housing, stereo inputs and outputs, and a mini USB port that receives MIDI messages from DAW (digital audio workstation) software as well as external MIDI controllers with USB host support. The C4 can also receive MIDI CC messages when connected to the Neuro Hub (also sold by Source Audio).


  • Six Preset Positions: Use the C4’s three-position toggle switch and two preset banks to save six easily accessible presets.
  • Growing Library of Published Presets: For quick access to a world of great tones, try sampling sounds from a vast collection of published presets created by the Source Audio team and the ever-growing C4 Neuro Community.
  • Unprecedented Sound Sculpting Options: The powerful Neuro Desktop Editor (Free download for Mac and Windows) and Neuro Mobile App (iOS and Android) offer maximum sound exploration possibilities. Use Neuro’s modular synthesizer inspired editor to create custom C4 Synth presets that can be burned directly to the pedal, saved to a private cloud based library or shared publically with other members of the Neuro Community.
  • Supreme Tracking: If tracking matters to you (and it should), you will be amazed by the lightning-quick, imperceptible latency of the C4 Synth.
  • 128 MIDI Accessible Factory Presets – The addition of a third-party MIDI controller with USB host provides access to any of the pedal’s 128 Factory presets.​
  • Stereo Inputs and Outputs: Use the Neuro Editor’s panning controls to route each Voice to any location in a full stereo spread.
  • Compact Design – The durable, anodized aluminum housing has a small footprint and sturdy hardware. Dimensions: L: 4.5 in./11.4cm x W: 2.75 in./7cm x H: 2 in./5.1cm (including knobs).
  • Universal Bypass™ – Select either analog buffered or relay based True Bypass.
  • USB Port – Class-compliant USB-MIDI allows the C4 to work as a plug-and-play device with recording software running on Mac and Windows recording software or any third-party MIDI controller with USB host. The USB port also offers connectivity to the Neuro Desktop Editor providing access to deep editing possibilities and pedal firmware updates.
  • ​External Expression and Tap Tempo Control — Use the Control Input jack with the Source Audio Dual Expression Pedal (expression control to multiple parameters) or Tap Switch (adjust LFO rates on the fly).

First Impression

Although I’m not a professional guitarist or reviewer, I like this concept a lot. The interface is simple and aimed at players. You do not lose yourself in menus but only need 4 knobs. Nice is that you can go very deep in an editor if you like. For less synthesis or sound design friends, one of the many presets can be used immediately. Definitely, a nice Synthesizer pedal that is even very attractively priced.

Source Audio C4 Synth is available now from selected dealers for $239 USD.

More information here: Source Audio

Available at our partners


Effect Pedals News


Be the first to comment

Leave a Reply

Your email address will not be published.