TASCAM Digital Interface
Encyclopedia
The Tascam Digital Interconnect Format (TDIF) is a proprietary format connector defined by TASCAM
that is unbalanced and uses a 25-pin D-sub
cable to transmit and/or receive up to eight channels of digital audio
between compatible devices. Unlike the ADAT
lightpipe connection, TDIF uses a bidirectional connection, meaning that only one cable is required to connect the eight ins and outs of one device or another.
The Initial specification available to implementers was called TDIF-1 Version 1.0.
The first product with this connector was the TASCAM DA-88
. That implementation did not include the ability to derive a word clock
synchronization between the DA-88 and another TDIF-1 device, so a BNC WORD CLOCK connection was required as well.(cite: DA-88 users manual) Later TASCAM products included the ability to sync to the TDIF-1 connection, although that still excluded the DA-88. (cite:DA-38 users manual). Other manufacturers vary in their completeness of implementation.
The signal labelled "word clock" in the TDIF-1 spec is delayed 270 degrees (90 degrees advanced) with respect to the word clock visible from the BNC word clock output. This is because the TDIF-1 spec was derived from the digital audio transmitter of the NEC uPD6381 DSP
used in the DA-88.
The TDIF-1 Version 1.1 specification includes parity and other channel information bits.
TDIF-1 Version 2.0 includes specification for double speed and quad speed (e.g. 96kHz and 192kHz) rates at reduced channel counts.
The TASCAM X-48 supports 96kHz at full channel count over 6 TDIF-1 connectors, using a post Version 2.0 specification.
TASCAM
TASCAM is the professional audio division of TEAC Corporation, headquartered in Montebello, California. Tascam is credited as the inventor of the Portastudio, the first cassette-based multi-track home studio recorders. Tascam also introduced the first low-cost mass produced multitrack recorders...
that is unbalanced and uses a 25-pin D-sub
D-subminiature (Professional Audio)
D-subminiature connectors are used to carry balanced analog or digital audio on many multichannel professional audio equipment, where the use of XLR connectors is impractical, for example due to space constraints....
cable to transmit and/or receive up to eight channels of digital audio
Digital audio
Digital audio is sound reproduction using pulse-code modulation and digital signals. Digital audio systems include analog-to-digital conversion , digital-to-analog conversion , digital storage, processing and transmission components...
between compatible devices. Unlike the ADAT
ADAT
Alesis Digital Audio Tape or ADAT is a magnetic tape format used for the simultaneous digital recording of eight analog audio or digital audio tracks at once, onto a Super VHS tape that is used by consumer VCRs.- History :...
lightpipe connection, TDIF uses a bidirectional connection, meaning that only one cable is required to connect the eight ins and outs of one device or another.
The Initial specification available to implementers was called TDIF-1 Version 1.0.
The first product with this connector was the TASCAM DA-88
DA-88
The DA-88 was a digitalmultitrack recording device introduced by the TASCAM division of the TEAC Corporation in 1993. This modular, digital multitrack device uses tape as the recording medium and could record up to eight tracks simultaneously. It also allowed multiple DA-88 devices to be combined...
. That implementation did not include the ability to derive a word clock
Word clock
A word clock or wordclock is a clock signal used to synchronise other devices, such as digital audio tape machines and compact disc players, which interconnect via digital audio. S/PDIF, AES/EBU, ADAT, and TDIF are some of the formats that use a word clock...
synchronization between the DA-88 and another TDIF-1 device, so a BNC WORD CLOCK connection was required as well.(cite: DA-88 users manual) Later TASCAM products included the ability to sync to the TDIF-1 connection, although that still excluded the DA-88. (cite:DA-38 users manual). Other manufacturers vary in their completeness of implementation.
The signal labelled "word clock" in the TDIF-1 spec is delayed 270 degrees (90 degrees advanced) with respect to the word clock visible from the BNC word clock output. This is because the TDIF-1 spec was derived from the digital audio transmitter of the NEC uPD6381 DSP
Digital signal processor
A digital signal processor is a specialized microprocessor with an architecture optimized for the fast operational needs of digital signal processing.-Typical characteristics:...
used in the DA-88.
The TDIF-1 Version 1.1 specification includes parity and other channel information bits.
TDIF-1 Version 2.0 includes specification for double speed and quad speed (e.g. 96kHz and 192kHz) rates at reduced channel counts.
The TASCAM X-48 supports 96kHz at full channel count over 6 TDIF-1 connectors, using a post Version 2.0 specification.