Using the HD24/EC-2 with the Alesis AI-4 AES/EBU Interface
The Alesis AI-4 AES/EBU Digital Audio Interface is
asingle-rack space unit available from your Alesis dealer that lets you connect ADAT Optical input and output signals to industry-standard AES/EBU digital signals, eight channels at a time. The AI-4 is designed to handle standard operation, as well as high sample rates (88.2/96kHz).
With the AI-4 you can:
•Export tracks from the HD24 to mastering units (such as the Alesis MasterLink), DAT recorders, and workstations
•Import tracks to the HD24 from any recorder or source with an AES/EBU interface.
Using the AI-4 at 88.2/96 kHz
The AI-4 is ALWAYS capable of eight-channel conversion, simultaneously—each of the AI-4’s four AES/EBU inputs and outputs carries a stereo signal, regardless of sample rate.
The only difference at the high sample rates is that a second pair of ADAT Optical cables must be used to connect the ADAT OPTICAL 9-16jacks on the back of the HD24 to the ADAT OPTICAL (5-8)jacks on the back of the AI-4. This is because the ADAT Optical interface transmits four channels of high-speed data, in the space used for eight channels of standard-speed data.
Remember that if you’re transferring more than eight tracks at a time to the HD24, and must do multiple passes, there should be some synchronization via ADAT Sync at the same time. If the workstation doesn’t have ADAT Sync, you should use multiple AI-4s to download all tracks at the same time.
Word clock
In a simple transfer between the HD24 and the AI-4, a separate word clock connection is not necessary, because word clock is contained within the ADAT Optical signal. However, in more complex multipath situations, the AI-4, HD24, and all other digital devices in the studio should be connected to a separate word clock generator and set to use this external word clock source as the timing reference.
