21 SOLID STATE AM/FM/FM STEREO MODULAR SYSTEMS AND TUNER AMPLIFIERS AND MATCHED SPEAKERS, BASS AND TREBLE TONE CONTROL THEREOF, BALANCE, VOLUME, AFC AND SIX-POSITION FUNCTION CONTROLS THEREOF, JACKS FOR STEREO TAPE RECORDERS [ , HEAD PHONES THEREOF, AND TRANSISTOR 2-CHANNEL TRANSCEIVERS ]