9 Electrical apparatus for use with musical instruments, namely, guitar, bass, keyboard and musical instrument amplifiers; audio processing equipment, namely, audio signal processing equipment for processing musical instrument audio signals in the nature of limiters, compressors, gates and expanders; electrical circuits for musical instrument amplifiers, namely, tube and solid state amplification circuits, volume and tone control circuits, overdrive and sustained overdrive circuits, non-overdrive circuits, reverberation and tube reverberation circuits; cabinets for loudspeakers and musical instrument amplifiers; extension speaker cabinets; speaker cabinets; loudspeakers; components and accessories for guitar, bass, keyboard and musical instrument amplifiers, namely, amplifier foot pedal controls, and amplifier switches; replacement parts for guitar, bass, keyboard and musical instrument amplifiers, namely, cables, connectors, knobs and amplifier handles