The Snake Oil Fine Instruments Marvellous Engine is an analog distortion guitar pedal inspired by classic higher-gain British amplifiers, designed to add rich overdriven tones to a rig1. It runs on 9V DC center-negative power and draws 10mA1.
What it is and where it came from
On a That Pedal Show demo, the presenters took the British-amp reference further: to Dan's ear the pedal pointed toward a Marshall-style sound4. Guitar.com's reviewer, Richard Purvis, framed the circuit another way, writing that "Taking the immortal ProCo RAT as a reference point, Snake Oil's coppery contraption offers the same kind of smooth saturation"2.
The controls: Gain, Level, Tone, Voice
The pedal's front panel carries Gain, Tone and Level, with the Voice switch tucked under the casing13.
| Control | What it does |
|---|---|
| Gain | Sets distortion intensity1 |
| Tone | Shapes the high-to-low frequency balance1 |
| Level | Sets the output volume1 |
| Voice | Engages a second clipping stage for added edge and presence1 |
The Voice switch is the pedal's distinguishing control. It sits under the casing rather than on the top panel, and gearnews described it as giving you an extra clipping stage3. Guitar.com's review put it in stronger terms: "This allows you to dial in a second clipping stage, adding a whole lot of extra sting to a tone that's already as fiery"2.
The Voice switch is located under the casing, not on the top panel, so it is easy to miss when setting the pedal up3.
What reviewers heard
On That Pedal Show, the presenters compared the Marvellous Engine against familiar reference points, with Dan hearing it as "sounds like a more aggressive angry Charlie to me yeah so rough around the edges", smoother than a Marshall 800-style distortion, with the edges back and a pretty dark sounding low end4.
RockBoard's PedalPedia describes the Marvellous Engine as inspired by classic higher-gain British amplifiers and designed to add rich overdriven tones to your rig1.
Power and practicalities
The Marvellous Engine runs on 9V DC, center negative, and draws 10mA, according to RockBoard's PedalPedia's product listing1. That low current draw means it sits comfortably alongside typical pedals on a shared power supply.
The pedal also appeared in a That Pedal Show Pick'N'Mix episode, with its segment starting at 8:075.
Videos
Rob Chapman
Peter “Danish Pete” Honoré
Perfecto De Castro
Questions
Where is the Marvellous Engine made?
The Marvellous Engine is made in the UK. Guitar.com's review of the pedal lists it as made in UK, and on a That Pedal Show demo the presenters confirm it is made in the UK. The brand debuted at NAMM 2019 with two UK-made pedals, the Marvellous Engine distortion and The Very Thing overdrive/boost.
What does the Voice switch do on the Marvellous Engine?
The Voice control engages a second clipping stage, which the maker says adds edge and presence. Gearnews notes the switch sits under the casing, and Guitar.com's reviewer wrote that it adds a whole lot of extra sting to a tone that is already fiery.
Is the Marvellous Engine analog?
Yes. The maker's product listing describes the Marvellous Engine as an analog distortion guitar pedal, with an analog circuit type.
What power does the Marvellous Engine use?
The Marvellous Engine runs on 9V DC, center negative, and draws 10mA according to the maker's product listing.
How much did the Marvellous Engine cost?
The Marvellous Engine carried an RRP of GBP 149 when the brand launched at NAMM 2019, and Guitar.com's August 2019 review also lists the price as £149.
Sources (5)
- Marvellous Engine by Snake Oil Fine Instruments, RockBoard PedalPedia, 2026
- Review: Snake Oil Fine Instruments Marvellous Engine and The Very Thing, Guitar.com, 2019-08-22
- NAMM 2019: Rob Chapman's Snake Oil Fine Instruments pedals, gearnews.com, 2019-01-25
- Danelectro Eisenhower, Snake Oil Marvellous Engine, Supro Delay, Meris Mercury 7, That Pedal Show (YouTube), 2019-05-06
- Danelectro Eisenhower, Snake Oil Marvellous Engine, Supro Delay, Meris Mercury 7, That Pedal Show, 2019-05-06
