xaelonThis has more power, a better interface (OLED), and more capability (adds SPDIF optical+coax input, bass boost, 3 gain settings all on front panel, and more). Can't recall if the fulla2 has a 1/4" jack, but XD-05 does and I prefer it. I think the sound is quite nice, the AKM4490 is a good DAC. Oh and it also has a battery! (which is why it has more power, as it doesn't use your device's USB power)... On the downside it's a little more finicky with USB and the included cables are crap, don't use them. Also you won't get any warranty service and it costs more... They are different and both great, though the Fulla2 has limited use to me other than being inexpensive - it's stuck on desktop IMO (or nightstand, but no spdif) and there are better DAC/Amp combos if you want one for desktop use. Good to build a Schiit stack or just to get the DAC and USB interface for a special analog amp you love?