Does the Spotify Connect volume control reduce quality?

[fwolff]

Spotify Premium, android  

Couldn't find any consistent answer on the internet regarding this question.

When an analog source is streaming via Spotify connect (Xiaomi mi box 3 connected to stereo receiver via 3.5mm to RCA), does the Spotify connect volume control acts as a digital volume control, compressing the digital signal? Or does it just send a message for the device to attenuate the analog output?

I really need to check if I should keep the Spotify volume at max and only use the receiver remote, or if the volume control acts on the already decoded signal, like chromecast audio does.

Thank you very much