By hooking up the better DACs available, Vega, Yggy and a Master 7 to 4 amps I have tried: ECBA, SPL Phonitor, Compass 2, Jot. I heard much more details with the better amps like ECBA compared to the Jot. I heard micro details being grossed over in the Jot. By comparing the internal DAC and Vega and Yggy, feeding to the amp of the Jot, I heard much more details. I haven't heard the Gumby, but I heard from friends that the resolution is close to Yggy, so I speculate with the Gumby here. So my conclusion was the amp of the Jot was much more capable than the internal DAC, but not to the level of Yggy. And I also make assumptions that the Bimby or Mimby being more resolving than the internal DAC, which I think should be the case. To my ears, no ABXYZ tests.