The Acorn Amps Mind Killer is a dual distortion pedal: two separate op-amp distortion circuits wired in series, each with its own footswitch so you can stomp them in independently or run both together12. The maker describes it as featuring "two separately stomp-able distortion circuits in series"1. It is a distortion pedal in the classic two-stage mold, with a Dune theme that carries through to the control names and the blue LEDs on the face of the pedal2.
Two circuits, one pedal
The core idea is simple: two discrete op-amp distortion circuits, wired in series, that can be activated independently2. Each side has its own footswitch, so the Mind Killer works as a single distortion, a two-stage gain stack, or anything in between. gearnews.com's Jef, covering the announcement, described the range as "everything from nice high gain overdrives to fuzzed out hyper distortions," and wrote that kicking in both circuits gives "massive, ultra-dirty tones"2. He added that "the ability to bring in both two sides in series and the two extra modes on each side make this distortion stand out for" tonal variety2.
Controls
Each side of the pedal carries the same set of controls, so the two circuits are matched in what they offer2:
| Control | What it does |
|---|---|
| Spice | Drive control for that side's distortion circuit2 |
| Life | Volume control for that side's circuit2 |
| Bass boost switch | Gives more low end on that side2 |
| Clipping diode switch | Removes the diodes used on that side, for a much cleaner op-amp drive2 |
The bass boost and clipper diode toggles are on each distortion circuit, per the maker's product page1. Guitar World's news coverage of the launch likewise describes the pedal as having "each with bass boost and clipping diode toggle switches"3.
The clipping diode switch changes the character of a side considerably: with the diodes out of circuit, you get the op-amp's own cleaner drive rather than diode clipping, which is a different tool on the same pedal2.
Power and build
The Mind Killer runs from an external 9-volt power supply2, with RockBoard's PedalPedia listing the voltage as 9V DC, center negative4. Acorn Amplifiers says the pedal is "Assembled entirely with high-quality, audio grade components and rugged latching foot switches and metal Switchcraft jac"1, meaning metal Switchcraft jacks and latching footswitches alongside the audio-grade parts.
Price and availability
Acorn Amplifiers lists the Mind Killer at $225.00 USD on its product page1. That matches the USD 225 RRP gearnews.com reported when the pedal was announced on 15 October 2020, at which point it was open for pre-order with shipping expected by 20 November2. Guitar World reported the pedal as available now for $225 in its 16 October 2020 coverage3.
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Questions
Is the Acorn Amps Mind Killer true bypass?
Yes. Acorn Amplifiers lists the Mind Killer as true bypass on its product page, and gearnews.com's coverage of the pedal's 2020 announcement also describes it as true bypass. That means the pedal's circuits are taken completely out of the signal path when it is off, so it will not load or color your clean tone when switched out.
Can you use both sides of the Mind Killer at once?
Yes. The two distortion circuits are wired in series and each has its own footswitch, so you can run either side alone or kick in both together. gearnews.com's Jef wrote that kicking in both circuits gives massive, ultra-dirty tones, and that running both sides in series plus the two extra modes per side is what makes the pedal stand out for tonal variety.
What do the Spice and Life knobs do?
Each side of the Mind Killer has two knobs. Spice is the drive control and Life is the volume control, so each circuit gets its own amount of distortion and its own output level. That lets you set one side as a lower-gain stage and the other as a heavier one, then combine them.
What do the bass boost and clipping diode switches do?
Each distortion circuit has its own bass boost and clipper diode toggle switches. The bass boost switch gives you more low end on that side. The clipping diode switch removes the diodes used on that side of the pedal, which gearnews.com describes as producing a much cleaner op-amp drive instead of diode clipping.
What power supply does the Mind Killer need?
The Mind Killer runs from an external 9-volt power supply, center negative. There is no internal battery option mentioned, so plan on a spot on your pedalboard power supply or a dedicated 9V DC adapter.
How much does the Acorn Amps Mind Killer cost?
Acorn Amplifiers lists the Mind Killer at $225.00 USD on its product page, and that matches the USD 225 RRP gearnews.com reported when the pedal was announced in October 2020. Guitar World reported the pedal as available for $225 at that time.
Sources (4)
- Mind Killer Dual Distortion, Acorn Amplifiers
- Acorn Amps Mind Killer Dual Distortion: Spice up your tone with this Dune-inspired pedal, gearnews.com, 2020-10-15
- Acorn Amplifiers unleashes the Mind Killer dual-channel distortion pedal, Guitar World, 2020-10-16
- Mind Killer by Acorn Amplifiers, RockBoard PedalPedia, 2026
