In Stock. 45 Day Lowest Price - 100% Satisfaction Guarantee. For years guitarists have been searching for a way to amplify and enhance the sound of their acoustic instruments on stage and in the studio. Now, with Yamaha's Acoustic Microphone Modeling (AMM) technology, guitarists can achieve a more natural acoustic electric sound without having to spend thousands of dollars on world-class microphones and effects. Select one of the eight microphone simulators that include condenser, dynamic, tube, and even a nylon string simulation. Other features include feedback reduction, 4-band parametric EQ, 30 presets, built-in tuner, and digital out.