The Joyo Roll Boost is a compact boost pedal from Joyo, sold as the JF-38 Roll Boost on the maker's site1. It uses class A circuitry to deliver up to 35dB of boost, set by a single gain knob, and it is designed to raise your level without coloring your sound12.
A transparent class A boost of up to 35dB
The Roll Boost's job is simple: it makes your signal louder, cleanly. Joyo describes the circuit as "Classic A circuitry, a flip of the switch gives you up to a 35dB boost"1. MusicRadar's reviewer, Trevor Curwen, describes it the same way, as offering "up to 35dB of boost via class A circuitry, the amount being set by a single gain knob"2.
That 35dB is a large amount of gain for a boost pedal. With the gain knob at its minimum there is no boost, and advancing it clockwise gives a workable range from subtle level increases upward2. Because the pedal is tonally transparent, the extra level pushes your amp harder rather than adding its own character2.
| Control | What it does |
|---|---|
| Gain knob | Sets the amount of boost; at minimum there is no boost, and turning clockwise increases it from subtle upward2 |
The pedal is compact at 118 x 62 x 56mm and weighs 0.24KG, so it takes up little board space1. It uses true bypass switching, which leaves your signal untouched when the pedal is off1. For power, it supports a maximum input of 18V DC voltage1.
What reviewers said
MusicRadar's review, written by Trevor Curwen, was positive. The reviewer's list of likes included the compact size, the simplicity of use, the tonal transparency, and its usefulness for driving valve amps2. The one drawback noted was the four-screw battery access, meaning changing the battery requires unscrewing the back plate2.
"The Roll Boost offers transparent boost when you need it at a budget price and is doubles as a viable alternative to an overdrive pedal for valve amps."
The overall verdict was "Blimmin' excellent"2.
Boost or overdrive?
Because the Roll Boost raises level without changing your amp's tone, it works differently from an overdrive pedal, which generates its own clipping and character. MusicRadar's reviewer found it doubles as a viable alternative to an overdrive pedal for valve amps2: the extra level pushes the amp's preamp into breakup, so the drive comes from the amp rather than the pedal. Into a clean or solid-state amp, it simply makes you louder rather than driving the amp into distortion.
If you want a boost with a different flavor, Joyo also makes the Joyo Rated Boost and the Joyo Wild Boost, and the hand-aged Rock N' Roll Relics Stinger Boost is another take on the same job, with 9-volt operation via external power supply or onboard battery and true bypass switching3.
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Questions
Is the Joyo Roll Boost the same as the JF-38?
Yes. The Roll Boost is Joyo's JF-38 model, listed on the maker's site as the JF-38 Roll Boost. It is part of Joyo's 10/30 Series of compact pedals, and the name Roll Boost is the product name while JF-38 is the model number.
Can the Joyo Roll Boost replace an overdrive pedal?
MusicRadar's reviewer found that it can, in one role: because it drives a valve amp harder without adding its own character, it works as a viable alternative to an overdrive pedal for pushing valve amps into breakup. It is a boost, not a drive pedal, so it does not generate overdrive on its own.
Does the Joyo Roll Boost change my amp's tone?
No, that is the point of it. MusicRadar describes it as tonally transparent, increasing gain without changing your amp's tone. It raises the level going into the amp rather than coloring the sound, so what you hear is your existing tone, just louder and pushed harder.
How do you change the battery in the Joyo Roll Boost?
The battery is accessed by removing four screws from the enclosure. MusicRadar's review lists this four-screw battery access among the pedal's drawbacks, so most players will find a 9V DC power supply more convenient than swapping batteries.
Sources (3)
- JF-38 Roll Boost_JOYO, JOYO, 2019-12-17
- Joyo Roll Boost review, MusicRadar, 2012-07-11
- Rock N’ Roll Relics Launches Guitar Pedals, Premier Guitar, 2025-03-25
