Hi,

On the G61 MD1 is the upper row of 3 inputs marked as L/R, Centre/LFE and Surround.
MD2 is the lower row.

Brian

Main: G65, MD600 Sooloos, MC200 Roon Core, MS600, 210, 218, UHD722, DSP5200SE, DSP5200HCSE, M6 & DSW.2
System 2: AC200 MS200, WiiM Pro+, M6.
Other: DSP5000 (96/24v1), DSP3300.