There are balanced line tube preamps out there.
Be advised that most high end audio products don't support the balanced line standard even though they are balanced. If they support the standard, things like ground loops go away and audible cable differences are minimized. When the standard is not supported you can still have ground loops and you may have to pick the right cable to get the system to sound right.
Be advised that most high end audio products don't support the balanced line standard even though they are balanced. If they support the standard, things like ground loops go away and audible cable differences are minimized. When the standard is not supported you can still have ground loops and you may have to pick the right cable to get the system to sound right.