Abstract: A musical instrument amplification system comprising a footswitch and a main amplification device, its control panel having a variety of controls, such as switches, sliders, dials and the like allowing the user to set a variety of parameters for amplification. A remote footswitch having several controls is connected to the front-panel, the controls may be assigned either to a set of specific amplification parameters, or to the control for a particular parameter, allowing the performer improved access to the amplifier controls whilst performing.

Abstract: A solid state audio amplifier for connection with a loudspeaker cabinet or emulation thereof to provide amplification characteristics emulating in frequency response those of a valve audio amplifier driving a loudspeaker cabinet. The loudspeaker cabinet comprises a loudspeaker drive and its enclosure. The frequency response of the audio amplifier exhibits a low frequency resonant peak in gain representing the fundamental resonance of the loudspeaker cabinet and a monotonic increase in gain at higher frequency associated with the impedance provided voice coil inductance of the loudspeaker cabinet. The audio amplifier comprises an amplifier and gain control circuitry associated therewith. The amplifier comprises a differential amplifier and the gain control circuitry comprises a impedance network connected in feedback. The impedance network comprises a tuned circuit connected to create the low frequency resonant peak in gain and a reactance providing the increase in gain at higher frequency.