Amplifiers
Projectors (image)
Ratings
Recording systems
Electrical properties and phenomena
Electrical impedance
Standardized parameters
Audiovisual materials
Headphones
Preamplifiers
Electronic equipment and components
Audio systems
Television systems
Microphones
Voltage
Television
Television equipment
Rated voltage
Recording equipment
Communication equipment
Audio equipment
Video tape recorders
Rated resistance
Loudspeakers
Tape recorders
Video recording
Radio receivers
Educational equipment
Interfaces
Record-players