The M400 pairs a true strobe display with five custom presets, switchable bypass and a 9V output that can power the next pedal on your board.
More than half a century after its first effects pedals, MXR has finally made a tuner, and it’s borrowed the engine from one of the most respected strobe tuners on the market. The M400 Turbo Tuner is a collaboration with Sonic Research, which designed the pedal around its original Turbo Tuner while Dunlop looks after production and distribution. According to Sonic Research, the M400 has everything its ST-300 offered, plus a switchable buffer.
Catch up on all the latest news here.
Founded by Marty Jensen and based in Carson City, Nevada, Sonic Research has built its name on strobe tuners. Its Turbo Tuner range covers the benchtop ST-122 and the ST-200 and ST-300 stompboxes, which have turned up on the boards of Radiohead’s Ed O’Brien, Andy Timmons and Julian Lage. The company has only ever sold direct through its own website, so an MXR version puts its technology on music store shelves.
Rather than a needle or row of LEDs settling on a note, a strobe pattern spins right when you’re sharp and left when you’re flat, slowing as you get closer and stopping dead once you’re in tune. “At its center is a big, bright true strobe display, driven by the analog signal straight from your instrument,” says MXR, which claims fraction-of-a-cent accuracy with no lag.
Beyond standard chromatic tuning, the pedal stores five customisable presets for instruments with up to 12 strings. Each string can be offset by up to 50 cents either way in 0.1-cent steps, which opens it up to microtonal tunings or compensating for an instrument with a three-saddle Telecaster bridge. MXR also says the low-end tracking holds up on bass.
Switching between true bypass and a buffered signal path covers both camps of the pedalboard debate. In buffered mode, three sub-modes set how the tuner behaves: muting while you tune, staying on all the time with the footswitch handling the mute, or passing signal through with the footswitch toggling the display.
The display has four brightness levels and is readable in direct sunlight, and an automatic power-up mode means the tuner is ready as soon as the board is switched on.
A 9V passthrough output can power the next pedal in the chain, freeing up an outlet on your power supply. The MXR M400 Turbo Tuner is available now, and its USB-C port will handle firmware updates as well as editor software MXR says is on the way.
Head here to learn more
