The Source Audio Vertigo is a digital tremolo pedal that puts three vintage amp tremolo circuits in one box. Source Audio describes it as offering "three distinct voices of tremolo: warm bias, choppy opto, and swirling harmonic," selected with a center toggle1. MusicRadar's buying guide framed the same three as the optical-style tremolo from a 1967 Fender Vibrolux, the Fender "brownface" series' harmonic wobble, and a bias sound similar to the tremolo on a Vox AC302. It was the first of Source Audio's One Series line of pedals3, and it launched at $149 street4.
What the Vertigo does: three amp-style tremolos
Tremolo is volume that swells and dips at a set rate, and amps have done it three different ways over the decades. The Vertigo models each of them, and the center toggle picks which one you hear1.
| Mode | What it is | How Source Audio describes it |
|---|---|---|
| Normal | Asymmetrical optical | "Optical tremolo is the effect found in many combo amps of the 1960s. This version of tremolo relies upon a neon light bulb and a light dependent resistor called an 'optocoupler.'"1 |
| Harmonic | Dual frequency | "This unique effect first appeared in Fender 'brownface' amps. The engine is a very pleasing and complex tremolo that has characteristics reminiscent of a phaser."1 |
| Bias | Smooth, tube saturated | "This approach to tremolo involves using an LFO to modulate the bias voltage of the tubes in an amplifier. The result is a smooth amplitude modulation with a mild overdrive created by the tube saturation."1 |
Guitar Interactive's launch coverage described the Normal mode as "a devine renewal of the thumping 'opto trem' amplitude modulation found in vintage Blackface Fenders"3. The harmonic mode is the one that surprises players who have only heard standard amplitude tremolo: because it splits the signal into two frequency bands and modulates them against each other, it reads as a swirl rather than a chop, closer to a phaser than a volume effect1.
The controls: depth, speed, shape, level and mode
The front panel keeps things simple: four knobs and a mode switch27.
| Control | What it does |
|---|---|
| Depth | How deep the amplitude dip goes7 |
| Speed | The tremolo rate7 |
| Shape | Morphs the wave shape from square, to sine or opto, to sawtooth3 |
| Level | Output volume7 |
| Mode switch | Selects Normal, Harmonic or Bias1 |
The Shape knob is the control reviewers singled out. MusicRadar's buying guide called it "ace" and explained that "this adjusts between square wave, sawtooth and everything in between, while Source Audio's Neuro app can take the sounds into entirely different realms"2. A square wave gives the hard on/off chop, a sine gives a smooth swell, and sawtooth sits in between with an asymmetric character.
The pedal stores up to 6 different effects, with six slots arranged as two banks of three1. Reaching the second bank is a held-footswitch move: bypass the pedal, then press and hold the footswitch for around 8 seconds until the center LED turns from red to green7.
External expression control is also possible with Source Audio's Dual Expression Pedal and the Hot Hand 3 Universal Effects Controller3, and players who want deeper editing can take it into the Neuro app, which MusicRadar listed among its reasons to buy3.
Power and connections
The Vertigo runs on a 9V power supply2 and draws 165 mA1. There is no battery option; Premier Guitar's reviewer noted "you must plug in (adapter included)"5.
At 165 mA1, the Vertigo draws more current than most analog tremolo pedals. Players using a compact daisy-chain supply should check their power budget before adding it to a board.
Connections are 2x input and 2x output, supporting stereo I/O for what Source Audio calls "deep and wide stereo modulation"12. Bypass is Source Audio's Universal Bypass: the player selects between high-quality signal relays for true bypass and transparent buffers for analog bypass1. MusicRadar's buying guide lists it as true bypass2, which is one of the two settings.
The box includes the pedal, a Mini USB to USB-A cable, a USB-A to USB-C adapter and a quick reference card1.
MIDI and the Neuro Hub
The pedal has full MIDI capability, including program change and continuous controller messages, and Source Audio highlights "simplicity when coupled with the Neuro Hub MIDI Clock Sync your tremolo rate with external MIDI clock messages"1. Tap tempo is available with Source Audio's external tap tempo switch, along with MIDI functionality when coupled with the Neuro Hub4. For players building a MIDI rig, the Vertigo fits alongside Source Audio's other MIDI-capable pedals such as the Ventris reverb and the EQ2 Programmable Equalizer.
History: the first One Series pedal
The Vertigo arrived in 2015. MusicRadar had reported that January that Source Audio had seven new stompboxes set to emerge over the next year8, and in July Source Audio announced the Vertigo Tremolo with an MSRP of $209 and a $149 street price4. Guitar Interactive reported it in stores as of July 3, 2015, quoting the company: "The Vertigo is the first of our new One Series line of pedals"3. Premier Guitar's later review noted that the One Series line "bucks 'for geeks only' stereotypes"5.
In 2023, Source Audio released a limited edition in collaboration with Roger Miller of Mission of Burma, sold exclusively at The Music Emporium for $2499. Miller worked closely with Source Audio's engineers to recreate a mode voiced after his signature custom and extremely rare Vacu-Trem pedal7, a circuit Delicious Audio described as having "a hard chopping wave shape with above average tremolo speed"7. The special edition keeps the same Depth, Speed, Shape and Level knobs7 but swaps in three modes tied to the band's songs: Trem, voiced after "Tremelo"; Secrets, an accelerated tremolo capturing the opening of that song, with speeds as high as 50Hz; and Two, recreating the effect on "Trem Two"7. Its case carries the graphics of the cover of the band's album "Vs."7.
What reviewers said
MusicRadar's Trevor Curwen reviewed the Vertigo and concluded it is "the perfect buy if you want a tremolo pedal but don't want to be stuck with one sound"10. The buying guide's overall verdict was that "the Vertigo combines authenticity and eccentricity in perfect harmony"2, listing versatility, the Shape control and the Neuro app as reasons to buy, and "not much" as reasons to avoid2. Premier Guitar's review of the One Series noted the line's accessibility5, and a later Premier Guitar review of the True Spring reverb referred to "Source Audio's excellent Vertigo tremolo pedal" in passing11.
The Vertigo remains part of Source Audio's current lineup, with the maker's product page listing free US delivery within 5-7 workdays and a 2 year warranty1.
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Questions
Does the Vertigo Tremolo have tap tempo?
Yes, but not built in. Tap tempo works with Source Audio's external tap tempo switch, and the pedal also offers MIDI functionality when coupled with the Neuro Hub. So a player who wants tap tempo on the board needs the extra switch or the Hub rather than tapping the pedal's single footswitch.
Can the Vertigo sync to MIDI clock?
Yes. The pedal has full MIDI capability, including program change and continuous controller messages, and when coupled with the Neuro Hub it can sync the tremolo rate to external MIDI clock messages. That makes it possible to lock the wobble to a sequencer or drum machine tempo.
Does the Source Audio Vertigo take a battery?
No. There is no battery option, so the pedal must be plugged in, and Source Audio includes an adapter in the box. It runs on a 9V power supply and draws 165 mA, which is enough current that a small daisy chain may be worth checking before committing to it.
Is the Vertigo true bypass or buffered?
Both, by choice. Source Audio's Universal Bypass lets the player select between high-quality signal relays for true bypass and transparent buffers for analog bypass. MusicRadar's buying guide lists it simply as true bypass, which is one of the two available settings.
How many presets does the Vertigo store?
Up to six different effects, in six slots arranged as two banks of three. The center toggle selects the slots, and a second bank of presets is reachable by bypassing the pedal, then pressing and holding the footswitch for around 8 seconds until the center LED changes from red to green.
Who designed the Mission of Burma Vertigo Tremolo?
Roger Miller, guitarist of the post-punk band Mission of Burma, worked closely with Source Audio's engineers on the limited edition. It recreates a mode voiced after his signature custom and extremely rare Vacu-Trem pedal, and it was sold exclusively at The Music Emporium for $249.
Sources (11)
- Vertigo Tremolo, Source Audio
- Best tremolo pedals for guitar: Shake up your tone, MusicRadar, 2019-10-23
- The Vertigo Tremolo by Source Audio is Now Available in Stores, Guitar Interactive Magazine, 2015-07-03
- Source Audio Releases the Vertigo Tremolo, Premier Guitar, 2015-07-02
- Source Audio Vertigo Tremolo Review, Premier Guitar, 2015-08-14
- Source Audio Vertigo Tremolo, Pedal of the Day, 2016-01-16
- Source Audio Vertigo Tremolo Mission Of Burma LTD Edition, Delicious Audio, 2023-09-07
- NAMM 2015: 7 new Source Audio stompboxes, MusicRadar, 2015-01-21
- Limited-Edition Vertigo Tremolo by Source Audio, Premier Guitar, 2023-09-07
- Source Audio Vertigo Tremolo review, MusicRadar, 2016-06-07
- Source Audio True Spring Review, Premier Guitar, 2019-03-12
