sentence: Tape recorders combine knowledge both on mechanics and electronics.
sentences_before: This plastic tape is covered by a special magnetic substance which is being made into magnetic domains when it is being recorded. The tape recorder must have a record, playback and an erase head which transfer the signal onto the tape. The more expensive tape decks have three or six separate heads.
sentences_after: There must be very precise motors and moving parts, but also a complicated circuit board. It has to contain transistors, amplifiers etc.
concept_name: tape recorder
headings: Reel-to-reel tape recorders Technical information
categories: Magnetic tape