The question isn’t about marmite. It’s about science. If something sounds different there is a reason. The question is about the reason something sounds different. And about discovering with a double blind test whether something really does sound different or if we are somehow being deceived by other factors.

ROON Rock on an NUC across the systems
Sitting room: 218, DSP7200SE
Study: 218, Quad 303, Spendor BC1
Bedroom: Musical Fidelity A3CR, Chartwell LS3/5a
Various Sonos boxes in bathroom and spare rooms