Weiss 501 MK2 vs Nagra Tube DAC vs Nagra DAC II

[HKFEVER]

Hello, everyone, this is my first post, I am very new in audio or HIFI
Currently I have a Weiss 501 MK2 and would like to move on to different DAC, such as Nagra Tube DAC or Nagra DAC II.

Wonder anyone has the experience between these 3 models?