Portal:British Industries Company, BIC Series Z Turntables, Owner's Manual… (1970)
“ With the programming lever set to the OFF position, plug the power cord into a suitable outlet. Many amplifiers provide convenient receptacles on their rear panels, to which the turntable power cord may be connected. Often, these receptacles (Fig. J) are labelled "SWITCHED" and "UNSWITCHED". An unswitched outlet is powered at all times. A switched outlet is powered only when the amplifier is "ON". ”
