Pitch shows as a ring of LEDs around a note display. The pattern turns right when a note is sharp and left when flat, and slows as the string nears pitch. A slow crawl already means the string is within a fraction of a cent, so there is no need to wait for a full stop. Rated accuracy is ±0.02 cents.
Six presets sit on two arrow buttons. Chromatic reads all twelve notes, while Guitar and Bass listen only for open strings and show the string number. Three custom slots start as standard guitar, drop D and six-string bass. Each can hold up to 12 strings with offsets of ±50 cents in 0.1-cent steps, or a custom temperament. Flat tuning lowers everything by up to nine semitones, and the A4 reference runs from 300 to 599.9 Hz.
An internal toggle under the bottom plate picks relay true bypass, which mutes the output while tuning, or a buffer with three modes: mute, passthrough, or always-on with footswitch muting. A USB-C port handles firmware updates and editor software.
MXR · United States
Tuner · Released 20 October 2026
MXR Turbo Tuner (M400) is a strobe tuner pedal built around the core engine of the Sonic Research Turbo Tuner, released in 2026. Sonic Research designed it; Dunlop handles production and distribution.
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Walrus Audio