Digital tape recording system
Digital Tape Recording System ( DTRS ) was introduced by Tascam in 1993 . It is a recording system for recording studios that allows eight audio tracks to be recorded digitally on Hi8 cassettes.
Basics
As with analog video recorders or DAT, the recording takes place in helical tracking , in which the tape is threaded a little out of the cassette and wrapped around an inclined, very rapidly rotating head drum on which the recording heads are located. Depending on the DTRS model, sampling frequencies of 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz and 192 kHz can be selected. The higher the sampling frequency used, the fewer tracks are available for recording (at 192 kHz only two).
Different devices
The early models DA-38 and DA-88 can only record with a word length of 16 bits, later devices such as DA-78HR and DA-98 also with 24 bits, and this with the same tape running time.
Up to 16 devices of the DA series can be coupled very simply by connecting all machines with special synchronization cables to form a modular multi-channel system with up to 128 tracks. They are therefore also referred to as MDM (English: Modular Digital Multitrack, German: modular digital multi-track devices). A system of several coupled machines then behaves like a single recording machine with a corresponding number of tracks. In the network, only the drive buttons of the first machine (master) are operated and the other machines (slaves) follow automatically. Some models of the DA series can be synchronized to external devices (e.g. computers and professional video recorders) via SMPTE or MIDI time code (MTC).
Within less than three seconds after pressing the drive button PLAY on the master machine, all machines are running sample-precisely synchronized. Tracks that have already been recorded can only be heard at the moment of synchronization. The fast synchronization of a DTRS system is extremely advantageous, especially during studio recordings, since a very short lead time is sufficient before starting recordings. Systems from other manufacturers sometimes require far more than 10 seconds before all machines have synchronized with each other (and so all tracks can also be heard!), Which means that each time a new recording is started, a considerable amount of time is spent waiting for a long run-in must become.
Like earlier, analog tape machines, DTRS devices can get in and out of existing recordings (punch-in, punch-out). However, when starting a recording, all eight tracks are always rewritten to the tape, even if not all tracks are in the recording mode. Replacing the data of individual tracks would place too high demands on the precision of the drive mechanics due to the helical track method used.
DTRS machines are also used for surround recording storage and audio mastering purposes. It is not possible to save computer data on DTRS cassettes.
DTRS cassettes have running times between 30 and 113 minutes. This corresponds to a capacity of up to 4.8 GB of digital audio data. In addition to analog inputs and outputs, DTRS machines also have a digital interface in TDIF format (Tascam Digital Interface). A TDIF cable carries eight digital audio channels unbalanced and bidirectional. The 25-pin D-Sub plugs known from parallel printer connections are used as connections .
Although the DTRS system competes with hard disk recording methods, which in particular do not require rewinding times and the recorded data can be transferred between the recording device, computers and data carriers faster than in real time, the tape-based DTRS format asserts itself due to its reliability, modularity (expansion of the Multi-track system depending on the available budget), its robustness in live operation and its suitability as a secure and inexpensive backup medium. For several years, the DTRS format was a quasi-standard in the post-production area for the distribution of finished film sound mixes, but has been superseded by the WAV format in recent years .
See also
literature
- Hubert Henle: The recording studio manual. 5th edition, GC Carstensen Verlag, Munich, 2001, ISBN 3-910098-19-3
- Roland Enders: The home recording manual. 3rd edition, Carstensen Verlag, Munich, 2003, ISBN 3-910098-25-8