Kramer Electronics 6420 6420 is a high performance format converter for balanced audio signals. It converts two channels of balanced audio signals to AES/EBU, AES-ID3, S/PDIF and Toslink optical digital outputs simultaneously. S/N Ratio - 80dB. Standards - AES/EBU, AES-ID3, S/PDIF, Toslink Optical. Sampling Rates - 32, 44.1, 48kHz. Compact Kramer TOOLS - 3 units can be rack mounted side-by-side in a 1U rack space with the optional RK-3T rack.