Three heads for realtime monitoring of recordings and improved sound quality Three-head technology uses separate heads for recording and playback (the third of the three heads being the erase head). This allows different record and playback head gaps to be used. A narrower head gap is optimal for playback than for recording, so the head gap width of any combined record/playback head must necessarily be a compromise. Separate record and playback heads also allow off-the-tape monitoring during recording, permitting immediate verification of the recording quality. (Such machines can be identified by the presence of a monitor switch with positions for tape and source, or similar.) Three-head systems were common on reel-to-reel decks, but were more difficult to implement for cassettes, which do not provide separate openings for record and play heads. Some models squeezed a monitor head into the capstan area, and others combined separate record and playback gaps into a single headshell.
Three heads for realtime monitoring of recordings and improved sound quality Three-head technology uses separate heads for recording and playback (the third of the three heads being the erase head). This allows different record and playback head gaps to be used A narrower head gap is optimal for playback than for recording, so the head gap width of any combined record/playback head must necessarily be a compromise. Separate record and playback heads also allow off-the-tape monitoring during recording, permitting immediate verification of the recording quality. (Such machines can be identified by the presence of a monitor switch with positions for tape and source, or similar.) Three-head systems were common on reel-to-reel decks, but were more difficult to implement for cassettes which do not provide separate openings for record and play heads. Some models squeezed a monitor head into the capstan area and others combined separate record and playback gaps into a single headshell.