The two Dacs I mentioned are portable Dacs that double up as desktop too.Is this the same argument people use to buy a liniare power supply. Must the USB connector of the DAC not solving this problem?
They are also sensitive to this issue.
However, when used for their primary portable role, the issue does not arise. Connect them to a phone and headphones, and there is no problem.
They do not have isolation builtin, because that uses precious battery power.
But sometimes, the problem may not affect the Dac, but the amp that comes after!
HS-01 is a solution to a particular problem.
If you don't get it, then by all means, call it what you like.