Double-speed Tape-to-Tape Copying
| Field | Duplicating audio and occasionaly video tapes |
| Went Obsolete | Late 1990s- Early 2000s |
| Made Obsolete By | The decline in popularity of cassette decks and rise of rack-mount CD burners |
| Knowledge Assumed | The ability to engage the dubbing button and actuate the deck's play and record buttons |
| When useful | Duplication of tapes |
Basically these devices had two of pretty much everything in one unit. You started a play session on one side (usually the left) and a record session on the other side and pressed the 'double speed' button. Main problem with doing this is that sound quality generally suffered, as the recording circuitry in consumer equipment was not designed to handle high frequencies that are inaudible at single speed but should be preserved when copying at double speed. They were fine for voicer applications or making mix tapes for generic Walkman, however.
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It's also worth noting that a tape being copied at double speed could still be listened to, except that it would play at twice the pitch and twice the tempo, which was an amusing thing to a young 9 year old.