The motherboard is on the back of the display. You need to take the back of the display housing off. It’s relatively simple, even I can do it.

Sooloos, Roon, G series (with LPS upgrade), 800 series (with LPS upgrade), HD621, AC200, Prime and PS, DSPs old and new.

Purdeys, Moke, Leica, 'Blad. Only the best.