The AC-40 Acoustic Chorus Guitar Amplifier from Roland is a compact guitar amplifier with built-in stereo chorus and reverb effects, designed for solo acoustic guitarists, acoustic guitar duos, and singer/instrumental performers.

The AC-40 features two independent channels: a dedicated Guitar channel with a standard 1/4" input, and a Mic/Line channel with an XLR/1/4" TRS combo input to connect a microphone or a line-level device. You can plug in a guitar and a microphone for guitar/vocal performances, or use the channels to mix two types of pickups, such as an undersaddle and body pickup combination, or a pickup and an additional instrument microphone. Each channel has its own three-band EQ for sound shaping, as well as independent chorus and reverb controls. In addition, an anti-feedback function automatically suppresses feedback.

The AC-40's rear panel offers multiple connectivity options for a variety of situations. Connect an external music player to the stereo Aux In for backing tracks and practice, and use the dedicated level control to balance the sound. Mono/stereo Line Out jacks give you the ability to connect to PA systems when performing in larger venues, or to recording devices to capture natural sound along with the unit's stereo effects. Plugging into the Phones jack mutes the internal speakers. A jack is also provided for turning the reverb and chorus effects on/off with optional footswitches (sold separately).

Weighing under 12 pounds, the AC-40 is lightweight and portable, making it ideal for performing in small venues such as nightclubs, restaurants, and coffee houses. An integrated tilt-back stand allows you to angle the amplifier for more projection when placed on the floor or another flat surface. On larger stages, the AC-40 can also be used as a personal monitor.