[ Sound recording, manipulating, amplifying, reproducing and transmitting apparatus; ] electrical and electronic apparatus and instruments, all for audio amplification, [ for the graphic equalisation of sound signal frequencies, for mixing sound tones, altering sound tones, or effecting echo, delay and other effects; sound amplifiers; amplifiers for sound reproducing equipment and for use with musical instruments; amplifiers complete with loudspeakers and cabinets; valve amplifiers and digita...