Dual stereo audio to AES converter is reference quality audio A/D converter that will convert four analogue audio channels with highest possible quality and produce two AES3 stereo digital audio signals. Each converter has dual AES outputs which are available on balanced backplane. Only one output per converter is available on un-balanced backplane. Card may be used with, or without an external AES clock signal and may be run at nominal or double sampling rates. It has internal clocks for 48kHz and 44.1kHz based rates but can be used with any external sampling rate 29 to 100 kHz.