Thank you for your answer:D
Use Connex or Contrik Balanced wires. Wired is also getting complete different results between PC's. Just Hum signal at -120... -130dBFS just connecting a balanced with balanced 600E resistors build within a connector. But not on laptop's.
This means for me I do not know whether the cables are OK. For 50E cables exists double shielded as I use them for 50E asymmetric connections.
Victor uses a special modified balanced input with direct connection to the ADC (also using different ADC brand). Only the LDO is powered by a linear PSU. As soon he opens the shielded LDO box, hum is preset as I showed.
Also I do not know about balanced direct connections to the LDO IC's, where the oscillator loop picks-up some none pleased signals.
I will soon box the LDO and currently do not know to put the silent switcher within the same box or not. But for shure separated inside with a metal frame.
May also the input resistor of the ADI-2 Pro counts (18k), all to experiment within my puzzle ...
PS: may we share the findings on private emails... ??