The Electron Brothers Brass Knuckle High-Voltage All-Tube Overdrive is an overdrive pedal with a genuine all-tube signal path, the kind of circuitry normally found in a guitar amp's preamp section. Pedal of the Day's review describes it as a tube amp front end in a pedal, with a special circuit design aimed at making the output suitable for pedal boards, so the high-voltage tube circuit can sit on a board and feed an amp like any other stompbox1.
How the tube circuit works
What sets the Brass Knuckle apart from most dirt pedals is that no transistors or diodes do the clipping. The whole signal path runs through tubes, and an internal voltage multiplier provides 290 VDC, allowing the tubes to be biased as they would in a typical guitar preamp. That is the same operating point a tube would see inside an amplifier, rather than the starved voltages some tube pedals run at1.
The circuit is based on the much-revered British amps from the late 60s to early 80s, but it has been modified. Pedal of the Day describes the result as covering everything from classic-styled crunch to searing saturated lead tones, all dripping with pleasing harmonics1.
How it behaves and how it stacks
One thing players should know before buying into the amp-front-end idea: the Brass Knuckle does not clean up in the traditional sense. Pedal of the Day's review describes it as driven from the get go, always producing some degree of overdrive, while responding beautifully to the player's touch on low to mid gain settings1.
In other words, rolling back the gain does not turn it into a clean boost or a transparent pedal. It is always producing some drive, and at low to mid gain settings it responds to how hard the player digs in. Players looking for a pedal that goes fully clean may want to compare it against conventional overdrive pedals or a boost instead1.
Where it is designed to cooperate is with other dirt pedals. Being a real tube amp front end, Pedal of the Day reports that it loves being slammed by a boost or drive pedal, and its output section is designed to work well with most pedals, making stacking a normal part of how it is meant to be used1. It can also be thought of as a preamp in pedal form, since that is the section of the amp it reproduces.
What reviewers said
Pedal of the Day's 2023 review was enthusiastic about the pedal's scale of sound and its flexibility with amplifiers1.
"Driving any tube OR solid state amp into sweet, sweet sonic bliss, this pedal brings the real deal tones right to the forefront of any rig."
The same review calls the sounds big and describes the pedal as bringing real deal tones to the forefront of any rig, whether the amplifier downstream uses tubes or not1.
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Questions
Does the Electron Brothers Brass Knuckle clean up when you turn the gain down?
Not in the traditional sense. Pedal of the Day's review describes the Brass Knuckle as driven from the get go, meaning it is always producing some degree of overdrive. What it does instead is respond to the player's touch, particularly at low to mid gain settings, so dynamics and picking strength shape how the drive sits in the sound.
Is the Brass Knuckle a real tube pedal or does it use transistors?
It is a real tube pedal. The Brass Knuckle uses an all-tube signal path, the same kind of circuitry found in a guitar amp preamp, rather than transistors or diodes doing the clipping. An internal voltage multiplier provides 290 VDC so the tubes can be biased as they would in a typical guitar preamp.
Which amps is the Brass Knuckle based on?
The circuit is based on the British amps from the late 60s to early 80s that are much revered among players, according to Pedal of the Day. The circuit has been modified from those amp designs, though, to create a range of tones from classic-styled crunch to searing saturated lead tones.
Can the Brass Knuckle be stacked with a boost or drive pedal?
Yes. Pedal of the Day reports that, being a real tube amp front end, the Brass Knuckle loves being slammed by a boost or drive pedal. Its output section is designed to be friendly to other pedals and to work well with most of them, so stacking it in front of or behind another dirt pedal is very much part of the design.
Does the Brass Knuckle work with solid state amps?
According to Pedal of the Day's review, the Brass Knuckle drives any tube or solid state amp into what the reviewer called sweet, sweet sonic bliss, bringing what they described as real deal tones to the forefront of any rig. It is not limited to tube amplifiers.
Sources (1)
- Electron Brothers Brass Knuckle High-Voltage All-Tube Overdrive, Pedal of the Day, 2023-07-08
