MXR M400 Turbo Tuner Strobe Pedal Tuner

The MXR Turbo Tuner is the only tuner you'll ever need. Built around the core engine of the original Sonic Research Turbo Tuner, this pedal brings modern versatility to the gold standard in strobe tuning. Sonic Research engineered it to deliver the same fraction-of-a-cent, professional-grade accuracy, all built to the roadworthy standard that defines both Sonic Research and MXR. From soundcheck to the studio, the Turbo Tuner locks you in to play with conviction.

At the center of the Turbo Tuner is a big, bright strobe display that precisely tracks how close you are to pitch. There's no lag and no bouncing needles — you play a note, turn the tuning peg, and watch the pattern rotate instantly to reflect the actual motion of your string against a steady reference pitch. It's physics in action: the display is driven by the analog signal straight from your instrument, so it tracks with zero latency and no simulated guesswork. Sharp notes rotate right, flat notes left, and the closer you get to pitch, the slower the rotation. When it's just creeping along, you're within a fraction of a cent and good to go. Four brightness levels keep the display readable in any light. For most users, that's all there is to it: plug in, tune up, and play.

No matter how you play, this pedal has you covered with a Chromatic mode that tracks all twelve notes, plus five customizable presets. Guitar and Bass modes track your open strings and show the string number instead of the note name, while three more come pre-loaded with standard guitar, drop D, and 6-string bass tunings as starting points. Each of the five can be reprogrammed to support up to 12 strings, with offsets of ±50 cents in 0.1-cent increments — enough range for everything from alternate tunings to experimental microtonal work. An onboard USB port handles firmware updates and editor software to make those tweaks even easier.

You also get to choose how the Turbo Tuner sits in your signal chain. In True Bypass mode — the default, just like the original Turbo Tuner — the tuner mutes your output while it's on for silent tuning and drops completely out of your signal path when it's off. For transparent buffered bypass that keeps your high end intact across long cable runs, just flip the internal toggle switch. Three buffered submodes let you mute the output while tuning, run the tuner always-on with footswitch muting, or pass your signal straight through while the footswitch toggles the tuner.

With the MXR Turbo Tuner on your board, you'll tune up in seconds and hit that first note with confidence. No more guesswork. And it all comes with the rugged durability you expect, down to the heavy-duty footswitch and button design exclusive to Sonic Research — built to keep you in tune for decades to come.