audio frequency machines and apparatus, namely, phono-equalizing amplifiers, control amplifiers, preliminary amplifiers, main amplifiers, power amplifiers; personal stereos; stereo amplifiers; stereo receivers; radio tuners; stereo tuners; digital broadcasting receiving tuners; television receivers; audio and video receivers; digital audio and video network receivers; digital audio and video network players; optical disc players and recorders for audio and video; audio cassette players; audio...