Here are some of my favorite audio pairings in my current inventory:
Little Dot MK3 + DT990 Pro (RCA 5654, Mullard 6AM6S tube favorites)
Loxjie P20 + 58X Balanced (Reflector 6n3p-DR tube favorite)
Atom (or 789) + Takstar HF580
Apple Dac + Fidelio X2 (seriously wtf)
ES100, K3, or Apple Dac + Blon BL-03
ES100, K3, or Apple Dac + HyperX Cloud X
What are some of yours?