The Greer Amps Mizuki Blue is an analog overdrive pedal built around two cascading JFET gain stages, one stage driving the other, designed to replicate the feel and dynamics of two cascading tube gain stages. Greer Amps describes it as a dual-JFET overdrive whose JFET transistors were created to emulate the warm, responsive character of tubes in a solid-state format1.
Greer's pitch for the sound is broad: "From fat vintage grunt to a clear, musical boost, this circuit covers a wide tonal spectrum," and the maker says it stacks beautifully with other drives1. Guitar Pedal X profiled the pedal in October 2025, noting its $199 price point and that it was sold out on the Greer webstore at the time2.
Controls
The Mizuki Blue keeps to a three-knob layout: Volume, Gain and Tone. Both Greer and Guitar Pedal X describe the layout as simple and easy to dial in, covering tones from jazz and country to classic and hard rock12.
| Control | What it does |
|---|---|
| Volume | Sets overall output level |
| Gain | Sets the amount of drive from the JFET stages |
| Tone | Shapes the treble response |
Greer does not identify a specific amp or tube variety as the pedal's replication target, and Guitar Pedal X's reviewer Stefan Karlsson noted that "it doesn't say anywhere exactly which amp or tube variety it's set to replicate as a default!"2. His review also flagged a wish for more background: "While I would have liked to know more about its origins and provenance. And what benchmarks it was tuned from or targeted"2.
Power and the trim pots
The Mizuki Blue takes 9 to 18 volt negative center pin only, or a 9V battery1. With a 5mA draw at 9V1, it is a light load on a supply, but the polarity requirement rules out any positive-center adapter.
One thing the maker is firm about: the pedal has trim pots inside that set the bias of the JFETs, and Greer says they should NOT be adjusted, as doing so will cause problems with the circuit1. Leave them alone.
Availability and where it sits in the Greer range
Guitar Pedal X's October 2025 review reported the pedal as "currently Sold Out on the Greer Webstore, but should be available at certain dealers," with Andertons quoting UK stock due on 21 November2. Greer's own product page lists the price at $199.00 and suggests checking with dealers if sold out1.
The Mizuki Blue joins a Greer overdrive line that includes the Greer Amps Lightspeed Organic Overdrive, the Southland Harmonic Overdrive, the Supa Cobra and the Mori Drive. For a wider view of the category, see Overdrive Pedals.
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Questions
Does the Greer Mizuki Blue take a 9V battery?
Yes. Greer Amps lists the power requirement as 9 to 18 volt negative center pin only, or a 9V battery, so a battery works alongside a standard center-negative supply. Current draw is 5mA at 9V, which is light enough for most daisy-chain supplies.
Can the Mizuki Blue run at 18 volts?
Yes. The maker's power spec is 9 to 18 volt negative center pin only, or a 9V battery. It must be a negative center pin supply, and the pedal draws 5mA at 9V.
Should I adjust the trim pots inside the Mizuki Blue?
No. Greer Amps says the trim pots inside set the bias of the JFETs and should not be adjusted, because doing so will cause problems with the circuit. Leave them as set at the factory.
Does the Mizuki Blue stack with other overdrives?
Greer Amps describes the Mizuki Blue as covering a wide tonal spectrum, from fat vintage grunt to a clear, musical boost, and says the circuit stacks beautifully with other drives. Guitar Pedal X's review also treats it as a stacking-friendly overdrive.
Is the Greer Mizuki Blue sold out?
As of Guitar Pedal X's October 2025 review, the pedal was sold out on the Greer webstore but should be available at certain dealers, with UK stock due at Andertons on 21 November. The maker's own page notes a $199.00 price and suggests checking with dealers if sold out.
Sources (2)
- Mizuki Blue, Greer Amps
- Guitar Pedal X, Guitar Pedal X, 2025-10-14
