5.5.6 Common Systems and Characteristics: Open Reel Formats
5.5.6.1 SONY and Mitsubishi have both produced open reel digital systems for the recording studio market, and NAGRA produced a four-track field recording system, the NAGRA-D.
5.5.6.2 Sony/Studer’s DASH (Digital Audio Stationary Head) system has numerous variants, based on common formats for the digital tracks on tape. DASH I provides 8 digital tracks on ¼” tape and 24 digital tracks on ½" tape. DASH-II provides 16 digital tracks on ¼” tape and 48 tracks on ½" tape. Twin DASH formats are commonly used for ¼” stereo digital recordings and utilise twice the normal number of data tracks for each audio channel to increase the systems error correction capability so that tape splicing can be used for editing. Low speed formats double recording time by sharing data for each audio channel across multiple data tracks, halving the number of audio tracks available.
5.5.6.3 Nagra still support NAGRA-D Sony DASH and Mitsubishi Pro-Digi format machines are no longer manufactured. These formats are/were intended for high-end professional use and as a result were extremely expensive to support.
| Format | Variants | Carrier Type | Audio and data tracks | Digital Audio Standards supported | Interface |
|---|---|---|---|---|---|
| DASH | Three speeds – F (fast), M (medium) and S (slow) | ¼” or ½” tape | Up to 48 audio tracks plus control track | 16 bit at 32 kHz, 44.1 kHz or 48 kHz | AES/EBU SDIF-2 MADI interface |
| DASH-I (single density) and DASH-II (double density) | |||||
| Two tape widths Q (quarter inch) and H (half Inch) | |||||
| Mitsubishi Pro Digi | Stereo | ¼” tape | 32 kHz, 44.1 kHz or 48 kHz. 20 bit or 16 bit (with extra redundancy to facilitate splice editing) at 15 ips. 16 bit (normal redundancy) at 7.5 ips | AES/EBU or proprietary multi-channel interface | |
| 16 track | ½” tape | 32 kHz, 44.1 kHz or 48 kHz. 16 bit | |||
| 32 track | 1” tape | 32 kHz, 44.1 kHz or 48 kHz. 16 bit | |||
| NAGRA-D | ¼” MP | 4 audio tracks. Extensive metadata including TOC and built-in error recording | 4 tracks at up to 24 bit 48 kHz 2 tracks at 24 bit 96 kHz | AES/EBU |
Table 3 section 5.5 Open Reel Formats
