The DMM104 BAT from ATI Audio is a distribution amplifier for digital audio signals. The unit accepts AES/EBU and S/PDIF digital signals on four connectors - XLR, BNC, RCA coaxial and TOSLink.
It then outputs a clean copy of the original data stream to four RCA coaxial S/PDIF outputs and a single TOSLink optical S/PDIF output, without modifying the signal in any way (such as adding copy protection, for example.)
The DMM104-BAT can operate using either four AA batteries or an optional external 24VDC power module. Fresh alkaline batteries will provide a minimum of forty-hours of operation. The batteries are cut off by the introduction of external power and can be used as an automatically-switched backup power source.