Audio amplifiers Power amplifiers 28 Design and construction 24 Amplifiers, Vacuum-tube 11 Amplifiers (Electronics) 6 Design 6 Sound 6 Maintenance and repair 5 Amateurs' manuals 4 Amplifiers, Radio frequency 4 Analog electronic systems 4 Electronic circuits 4 Electronics 4 Equipment and supplies 4 Household electronics 4 Recording and reproducing 4 Amplifiers 2 Auditory perception 2 Fiber optics 2 Measurement 2 Noise 2 Optical communications 2 Optical fibers 2 Physiological effect 2 Public address systems 2 Transistor audio amplifiers 2 Integrated circuits 1 MathCAD 1 Triodes 1