The One Control Minimal Series Mosquito Blender Expressio with BJF Buffer is a clean blend pedal with expression control and a built-in buffer. It splits your guitar or bass signal into a dry path and an effects path, lets you set how much of each you hear, and adds a switchable BJF Buffer at the front. One Control describes the idea plainly: "Clean blending is a powerful way to use your effects pedals for new sounds."1
One Control's product page lists the pedal as sold out as of 26 October 2026.1
A clean blend with expression control
The pedal's core job is mixing. You send your dry signal through it and your effect through its loop, then set the balance between the two. What sets the Expressio version apart is that the blend level can be swept by foot: when an expression pedal is connected to the EXP terminal, the 0-100% knob can be operated with the expression pedal, so you can fade your effect in and out mid-phrase.1
The controls:
- MASTER: adjusts the overall volume, and can also boost the sound. One Control notes that by adjusting the volume you can also suppress sudden volume changes during effect blending, enabling stable operation.1
- 0-100% knob: sets the clean blend level, and can be operated from an expression pedal plugged into the EXP terminal.1
- POLARITY: inverts the polarity of the signal. One Control's advice is to set it to the one closer to the required tone while listening to the actual sound.1
- BJF Buffer: turns the BJF Buffer ON/OFF.1
The BJF Buffer is the same circuit One Control uses across its Minimal Series, available on its own as the One Control Minimal Series BJF Buffer. With the buffer on, the pedal measures 500kΩ input impedance and 60Ω output impedance, a combination that keeps your guitar's high end intact through long cable runs and pedal chains.1
Power and connections
The pedal runs on a DC9V adapter with a negative tip and a 2.1mm barrel connector, drawing 12mA. That is the standard center-negative supply most pedalboard power bricks provide, and the modest draw means it fits comfortably alongside other pedals on a shared output.1
Switching while playing
One control note worth knowing before you set up: for the POLARITY switch and the BJF BUFFER switch, switching noise may come out if you switch on/off while playing. Set both switches while the pedal is muted or between songs, and treat them as set-and-forget rather than performance switches.1
Where it sits in the Minimal Series
The Mosquito Blender Expressio is part of One Control's Minimal Series of small utility pedals with the BJF Buffer built in. Related units include the One Control Minimal Series Black Loop Deluxe with BJF Buffer, a two-loop switcher whose built-in BJF Buffer at the input can be switched on or off, and the One Control Minimal Series Pedal Board Junction Box with BJF Buffer, which shares the same 500kΩ buffer-on input impedance. If you want a blender without the expression control, One Control also makes the One Control Mosquito Blender Trail with BJF Buffer. For more on the circuit itself, see Buffer Pedals.1
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Questions
What does a blender pedal do with an effects loop?
A blender splits your signal into a dry path and an effects path, then mixes the two back together. One Control describes clean blending as a powerful way to use effects pedals for new sounds, because you can run a pedal fully wet and dial in as much or as little of it as you want, rather than relying on the pedal's own mix control. The MASTER knob adjusts the overall volume, and One Control notes it can also suppress sudden volume changes during effect blending for stable operation.
What does the polarity switch do on the Mosquito Blender Expressio?
The POLARITY switch inverts the polarity of the signal. One Control's guidance is to set it to the position closer to the required tone while listening to the actual sound. Because blending two paths can put them out of phase with each other, flipping polarity can restore the fullness of the combined tone.
Can I switch the polarity or buffer while playing?
One Control warns against it. For the POLARITY switch and the BJF BUFFER switch, switching noise may come out if you switch them on or off while playing. Set both switches before you start, or make changes between songs.
What power supply does the Mosquito Blender Expressio need?
It runs on a DC9V adapter with a negative tip and a 2.1mm barrel connector, the standard center-negative pedal supply. One Control lists the current draw at 12mA, which is light enough for almost any pedalboard power supply.
What is the input impedance with the BJF Buffer on?
With the BJF Buffer switched on, the pedal presents an input impedance of 500kΩ and an output impedance of 60Ω, according to One Control's product page. A high input impedance like that is what a buffer is for: it keeps the guitar's tone from being loaded down by the pedals and cable run after it.
