DASH is an acronym for Digital Audio Stationary Head, an open-reel digital audiotape format introduced by Sony in 1982. DASH is capable of recording 2, 24, or 48 tracks of digital audio on 1/4” (2 track) or 1/2” (24 or 48 track) audiotape on open reels up to 14".
DASH recorders reached peak usage in the 1990s before the widespread adoption of hard disk recorders and digital audio workstations (DAWs). DASH tapes should not be considered for use as archival elements as they are highly prone to dropouts, pops and other digital errors as they age. Tapes have been known to experience playback issues as early as five years from the time the original recording was made, particularly with tape stocks manufactured in the late 1990s.
The majority of DASH machines record 16-bit digital audio with a 44.1kHz or 48kHz sampling rate, but Sony's 3348HR and Studer's D827 are also capable of recording 24-bit digital audio at 44.1kHz or 48kHz and 20-bit digital audio at 96kHz.
24-track tapes only utilize half of the tape's width and can be played on the 48-track machines with no modifications. Similarly, 48-track tapes can be played on a 24-track machine, but only the first 24 tracks will be reproduced.
Audio data is recorded as linear PCM with a strong cyclic redundancy, allowing the tape to be physically edited with a razor blade like analog tape, and played back with no loss of signal. The heads are stationary, which is in contrast to DATs, ADATs and DTRS cassettes, which all record using a rotating head that helically scans the tape.
A 1/2" DASH machine.
This digital magnetic tape can hold up to 24 tracks of audio.