It’s a little complicated. Roon device settings refer to endpoint capabilities, not desired outcome. I would say:
- if using the analogue outputs on the 218, set to “Decoder and Renderer”
- if using the digital output on the 218 direct to SE loudspeakers, set to “Decoder and Renderer”
- if using the digital output on the 218 to anything other than SE loudspeakers, set to “Decoder”.
You will not get the MQA light on the 218 if Roon is doing the first MQA decode, or the output from Roon is not bit-perfect to the 218. Any DSP in Roon? Any volume normalization?