Designed to tilt upwards on the stage if you should want it to—and thus, earning its name in the process—the Kickback KB15 from Hartke is a 500W combo amplifier intended for electric basses. It utilizes class-D amplification technology, and a 15" HyDrive speaker to deliver a powerful sound. The input jack can accommodate both active and passive basses, and the on-board three-band EQ will let you dial in a variety of tones, augmented all the more by the shape-control circuit. When engaged, this switch applies a 20 dB filter to a given frequency area adjustable via a knob to the right of the switch. The circuit is designed to further enhance your bass's tone. This amplifier boasts both a headphones output for silent practice as well as an XLR output for feeding direct signal to the house, mixer, or recording interface. Should you wish to loop in an external 4 Ohm cabinet, you can do so through its 1/4" speaker jack on the rear. A built-in limiter protects both the speaker and the amp from overloads, and at approximately 35 lb, the amp is relatively portable and lightweight.