Multi-functional processor for acoustic instruments, with chorus and reverb. Also features an acoustic simulator that can be output to electric guitar amps. Thank you for viewing. I am selling this because I am replacing my preamp. It was working without any problems until today. The exterior has some scratches. It's a very sturdy and robust build, typical of Boss products. This is a sale of the main unit only. Please prepare a power supply. For an adapter, a center-negative 9V adapter for compact effectors is suitable. For batteries, six AA batteries are required. This is a model from a few generations ago in the AD series, but compared to the complex latest models, it has a very simple panel, making it easy to adjust instantly during a live performance, and it's a popular model even among professionals. Below is from the product description: ・AD-3 that makes your electric-acoustic guitar sound even more beautiful Effects that make your electric-acoustic guitar sound even more beautiful, mainly for live performances, and enhance the acoustic feel. It creates a rich sound with dedicated chorus and reverb optimized for electric-acoustic guitars. In particular, the chorus applies effects separately to the low and high frequencies, employing a 2x2 chorus that provides a natural and smooth spread. Also, the bottom and top controls designed specifically for electric-acoustic guitars allow you to freely adjust the natural acoustic sound. With the balanced output that can be directly connected to a PA system, you can send high-quality sound directly to the console. ・Equipped with anti-feedback and acoustic guitar amp simulator. Equipped with two types of anti-feedback to reduce howling, which often occurs when playing electric-acoustic guitars. In addition to the anti-feedback that allows you to set the frequency with a knob, you can quickly deal with sudden howling by using the anti-feedback auto, which automatically detects the frequency just by stepping on the pedal. And, it is also equipped with an acoustic guitar amp simulator to finish the original sound of the electric-acoustic guitar with a guitar amp. If you send it through this function of the AD-3, you can get a more natural electric-acoustic sound even with a guitar amp that is designed to produce sound for electric guitars.