MXR - M400 Turbo Tuner

Strobe tuning has always been the gold standard for accuracy — and now it lives on your pedalboard in a form that's ready for anything. The MXR M400 Turbo Tuner isn't just another tuner pedal with a fancy display. It's built around the same core engine that made Sonic Research's original Turbo Tuner a go-to for professional guitarists and techs who couldn't afford to be even slightly off. Sonic Research founder Roger Schlichtig engineered this one personally, and that matters — because the precision here isn't marketing language. We're talking 0.02 cent accuracy with a real-time strobe display that tracks pitch as it moves, not after the fact. You'll see exactly where your pitch is sitting, not just a blinking needle that tells you "close enough." Close enough is the enemy. Five customizable presets let you store tunings for different guitars, alternate tunings, or instruments with up to 12 strings. Need a ±50 cent offset for drop tunings or special intonation setups? It handles that too. Four brightness levels mean the display stays readable whether you're under blinding stage lights or in a dim rehearsal space. And when it comes to bypass, you're not locked into one mode — switchable true and buffered bypass with three buffered submodes gives you real flexibility to match whatever signal chain you're running. The 9V passthrough output is a genuinely useful touch, letting you power an additional pedal off the same supply. The USB-C port keeps things future-ready, supporting firmware updates and an upcoming editor. It's the kind of thoughtful engineering that shows up in daily use, not just on a spec sheet. For players who've always wanted strobe-level accuracy without a dedicated rack unit or a bulky standalone strobe, this is it. It tunes fast, it tunes true, and it's built to the same roadworthy standard that MXR has delivered for decades. Once you've tuned with this kind of precision, it's hard to go back. --- Specifications: - Brand: MXR - Model: M400 Turbo Tuner - Tuning Engine: Sonic Research Turbo Tuner - Accuracy: 0.02 cent - Display: Real-time strobe display - Presets: 5 customizable (supports up to 12 strings, ±50 cent offsets) - Display Brightness: 4 levels - Bypass: Switchable true/buffered bypass (3 buffered submodes) - Power Output: 9V passthrough to power an additional pedal - Connectivity: USB-C (firmware updates and upcoming editor software) - Power: 9V