Action Tuners String Master guitar tuner
**THE CLAIM **
As you pluck each string, the String Master automatically tunes your guitar by turning each peg with its motorized robotic grip.
**THE TEST **
I used it to tune my band’s electric and acoustic guitars.
**THE REAL DEAL **
Although it adequately tuned the electric, the tuner sometimes took 30 seconds to find the correct pitch for a single string on the acoustic. Worse, it completely detuned my E string and tightened my G until it broke.
**BUY IT? **
No. You’re better off turning the pegs manually.