The Ground Control Tsukuyomi is a midrange booster pedal from Montreal-based maker Ground Control Audio, launched in November 2018 as the company's fifth pedal1. It is a boost pedal with one knob and one switch: the Gain knob delivers up to 20dB of clean boost, and the Mids switch either leaves that boost flat across the audio spectrum or focuses an extra 12dB of gain on the 880Hz to 1kHz band1. Premier Guitar describes it as "a single gain control offering up to 20 dB of op-amp derived clean boost"2.
The name comes from the Shinto moon god2, and the pedal is a variation on Ground Control Audio's Amaterasu preamp circuit, featuring a JFET frontend and a 20dB gain amplifier stage3.
A clean boost with a switchable midrange push
The Tsukuyomi keeps its control surface to a minimum. A single Gain knob for adding up to 20dB of gain and one Mids switch govern the whole effect45.
| Control | What it does |
|---|---|
| Gain knob | Adds up to 20dB of clean boost across the audio spectrum14 |
| Mids switch (right) | Pedal acts as a straight volume boost5 |
| Mids switch (left) | Boosts the 880Hz to 1kHz band by an extra 12dB5 |
The pedal starts at zero: with gain at minimum and the extra mids stage out of the circuit, the sound is near-bypass4. That makes it usable as a subtle always-on lift or a full 20dB solo push, and the mids stage gives a second voice. Ground Control Audio says the pedal was designed "with a particular attention to tone preservation and carefully chosen boost frequencies"1, and that with the Mids switch engaged it gives your tone "a very different character altogether, helping your leads stand out in the mix"3.
Under the hood, the Tsukuyomi uses low-noise op-amp based cascaded gain stages with tight gain specifications1, built around a JFET frontend3. Guitar.com's reviewer, Richard Purvis, described both the Tsukuyomi and its sibling as "JFET-based boosters offering up to 20dB of gain"4.
Built on the Amaterasu preamp circuit
The Tsukuyomi is a variation on Ground Control Audio's Amaterasu preamp circuit3, built around a JFET frontend and a 20dB gain amplifier stage3. The booster launched at a street price of $1592.
Ground Control Audio describes the pedal's intended use in terms of pickups and amp setup: "This pedal is best used with single coils and very trebly amp setups to give your tone a velvety fullness while also adding a crunchy sweetness to humbuckers"3. So while the midrange push is aimed first at brighter rigs, humbucker players get a crunchier character from it rather than being left out.
The Tsukuyomi is mains-powered only: it runs on a 9-volt supply and takes no battery, and the supply is not included4. If your board runs on batteries, this pedal needs a power source before it will work.
What reviewers said
Guitar.com's Richard Purvis reviewed the pedal in June 2019 and scored it 9/10, with the verdict: "A dual-purpose booster that excels at adding bite to crunchy tones"4. He noted its true bypass and its single-knob, single-switch operation, with the mid-boost switch targeting the 880Hz to 1kHz band4.
Premier Guitar's reviewer took a quick-hit look in September 2023 and called it a "Simple, killer alternative for easily at adding zing, sting, and burn to single-coil-ish sounds," listing its street price at $1592.
"A dual-purpose booster that excels at adding bite to crunchy tones"
Availability and where it is made
The Tsukuyomi is made in Montreal, Canada2, and Premier Guitar described it as "this beautifully decorated, JFET-buffered stomp from Montreal, Canada"2. When it launched, it was available directly from Ground Control Audio's website and from select retailers1, at $1592. Guitar.com's UK pricing at review time was £1594.
Videos
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Pedalboard of the Day
Juan Antonio Music
Questions
Does the Ground Control Tsukuyomi take a battery?
No. The Tsukuyomi is mains-powered only and has no battery option. It runs on a 9-volt power supply, which is not included with the pedal, so you will need a 9V DC supply on your board before you can use it.
Is the Tsukuyomi true bypass?
Yes. Guitar.com's review lists true bypass among the pedal's features, and the Tsukuyomi is also JFET-buffered when engaged. With gain at minimum and the mids stage switched out, the pedal starts at zero, giving a near-bypass sound.
What frequency does the Tsukuyomi Mids switch boost?
The Mids switch targets the 880Hz to 1kHz band and adds an extra 12dB of gain there. With the switch in the other position, the pedal acts as a straight volume boost, so you can choose between a flat clean boost and a midrange push.
Does the Tsukuyomi work with humbuckers?
Yes. Ground Control Audio describes the pedal as best used with single coils and very trebly amp setups, where it adds a velvety fullness, while also adding a crunchy sweetness to humbuckers. Premier Guitar's reviewer called it a simple, killer alternative for adding zing, sting and burn to single-coil-ish sounds.
Where is the Ground Control Tsukuyomi made?
The Tsukuyomi is made in Montreal, Canada, by Ground Control Audio, a Montreal-based effects maker. It was the company's fifth pedal when it launched in November 2018 at $159.
Sources (5)
- Ground Control Unleashes Tsukuyomi Midrange Booster, Premier Guitar, 2018-11-21
- Quick Hit: Ground Control Tsukuyomi Review, Premier Guitar, 2019-07-29
- Ground Control Audio Tsukuyomi Midrange Booster, Delicious Audio, 2021-06-21
- Review: Ground Control Audio Tsukuyomi & Amaterasu, Guitar.com, 2019-06-05
- Ground Control Audio announces the Tsukuyomi Midrange Booster, Guitar.com, 2018-11-22
