The MOSTARD is a clean dynamic boost pedal from RhPf Electronics, launched in June 2026. It delivers up to +30 dB of clean gain that leans bright and gets brighter the more you push it, with a three-band EQ for shaping what comes after it. It lists at $149 USD and comes in a small enclosure1.
What it does to your sound
Delicious Audio's Paolo De Gregorio, reviewing the pedal at launch, described its range this way:
"Low settings are warm and smooth. High settings are glassy, focused, and cut through anything."
The gain itself is dynamic: it leans bright and gets brighter the harder you push it, so the pedal responds to how hard it is driven rather than sitting at one fixed tone1.
The controls
| Control | What it does |
|---|---|
| Gain | Adds treble as you turn it up, making the pedal more present and aggressive the harder you push it1 |
| Low | Tightens the bottom end without getting boomy1 |
| Mid | Smooths out boxiness or adds focus1 |
| High | Lets you dial in sparkle or tame harshness1 |
The Gain knob is the heart of the pedal's character. Because it adds treble as it rises, the MOSTARD naturally gets more present and aggressive the harder you push it, which is what makes it a dynamic boost rather than a flat volume lift1.
Boost or overdrive?
The MOSTARD is a boost, not an overdrive: it adds clean gain and shapes tone with its EQ rather than producing clipping of its own. If you want to compare it with RhPf's drive pedals, the maker's range includes the RhPf Electronics Shodhana, a two-knob balanced overdrive, and the RhPf Electronics Tri-Harmonic Phalanx, a parallel band gain stage unit covering boost, overdrive and fuzz. For the wider category, see Boost Pedals and Overdrive Pedals1.
What reviewers said
Delicious Audio's verdict at launch:
"It's a utility pedal that doesn't feel like a utility pedal. Leave it on all the time or stab it for moments that need t..."
The reviewer's overall view was that the MOSTARD makes everything after it sound better overall, whether left on all the time or engaged only for moments that need a lift1.
Videos
Philip Czarnecki and RhpF Electronics
Questions
How much clean gain does the RHPF Electronics MOSTARD add?
Up to +30 dB of clean gain. Delicious Audio's Paolo De Gregorio described that gain as leaning bright, and getting brighter the more you push it, so the pedal's character shifts with how hard it is driven rather than staying flat.
What does the Gain knob do on the MOSTARD?
The Gain control adds treble as you turn it up, which means the pedal naturally gets more present and aggressive the harder you push it. At low settings the sound is warm and smooth, while high settings are glassy, focused, and cut through anything.
How much does the RHPF MOSTARD cost?
The MOSTARD lists at $149 USD, as reported by Delicious Audio when the pedal launched in June 2026. It comes in a small enclosure.
Is the MOSTARD a boost or an overdrive?
It is a clean dynamic boost pedal, not an overdrive. It adds up to +30 dB of clean gain with a three-band EQ for shaping, and its tone stays clean, getting brighter and more aggressive only as you push the Gain control.
Sources (1)
- New Pedal: RHPF Electronics MOSTARD, Delicious Audio, 2026-06-23
