Lower “blue” I/O PCB from a Sonos Connect S2 streaming unit. Marked as Eton ET856. Has 1 x SPDIF optical 1 x coaxial optical 2 x RCA audio in 2 x RCA audio out Extracted from a unit with a damaged main PCB. Tested ok with identical S2 unit. Please check compatibility as I am not a Sonos expert!
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