DO use only a power limited listed or recognized stereo amplifier to power this product DON’T install near a telephone or intercom master. (70 Volt Peak Maximum / 20Hz-20kHz). INSTRUCTIONS FOR IMPEDANCE- MATCHING VOLUME CONTROLS Introduction By matching the minimum output impedance of the receiver or amplifier and adjusting volume, M&S™ impedance-matching volume controls eliminate the need for speaker selector boxes or other impedance matching equipment. Determining the Jumper Setting f