musical instrument digital interfaces, digital data interface cards, digital synchronization boxes for musical instruments, line mixers, digital data mixers, musical instrument tuners, digital displays, readers, writers and regenerators, audio sound cards, keyboard controllers, audio speakers and monitors, digital recording systems, computer audio input and output cards, audio microphone pre-amplifiers, audio patchbays, audio digital to analog and analog to digital converters, co-axial/optical bi-directional converters, universal serial port MIDI interfaces, serial and parallel port MIDI interfaces, MIDI through and merge boxes
Electrical and Scientific Apparatus