I have an old 5.1 sound system (Desktop Theater 5.1 by Cambdrige Soundworks) that was designed for connection to a PC, it's input is via 3 3.5mm audio jacks (one for front, one for rear, and one for centre+sub). (see this image to get the idea)

It still works, so I would like to connect it to a Smart TV (LG OLED48C14LB), but the only outputs from the TV I think will work (i.e carry 5.1 channels) are the SPDIF and eARC.

I have looked at the thread Plugging a 3-cable 5.1 speaker system into a single 3.5mm jack but that talks about plugging into a PC or Mac, which isn't what I'm after.

I have had a look on Amazon, and I found this sound card, but it's a sound card, so I assume it needs an OS to work, and I'm guessing the smart TV won't support it.

I also found this adapter box, so I could plug my 5 speakers in, but I would lose my sub woofer, as it is the hub for the other speakers, and doesn't accept RCA in, only 3.5mm jacks.

Is there something like the adapter box, but converts eARC or SPDIF into the 3.5mm jacks?

1 Answer 1


I have found a solution that works.

I bought the SOUTHSKY 5.1CH DAC Converter, and three RCA to 3.5mm cables (for example).

I plugged the SPDIF cable into the TV and the Southsky box, then used the converter cables to connect the RCA to the 3.5mm cables and then into the amp/subwoofer. All 5.1 channels worked.

If there is a more elegant solution, I would happily hear it.

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