Here’s what Fender say
The Acoustasonic™ 40 amplifier offers portable amplification for acoustic-electric guitar and microphone. It’s a simple, flexible “grab and go” solution for a variety of musical performance and basic public address applications, and it can also be used as an onstage monitor when combined with a PA system.
6” Speaker with “WHIZZER” Cone
For more effective high-frequency response, the Acoustasonic 40 bears the unusual distinction of being the only Fender guitar amp to use a “whizzer” cone—a small supplementary speaker cone attached to the voice coil of the amps 6” speaker.
For extra ambient depth and shimmer, the Acoustasonic 40’s instrument channel features a built-in chorus effect.
XLR and ¼” Inputs
The Acoustasonic 40’s convenient dual front-panel inputs include a standard ¼” jack for an instrument and an XLR input for a microphone.