Linear Power Supply for a MacBookPro

[mansr]

3 hours ago, Chopin75 said:

I  am wondering if using external LPS for Macbook may give better SQ than battery alone.

Whether on battery or external power, a multitude of switching regulators are used internally. Running on battery has the advantage that ground loops or other evils coupled through the power supply are impossible. An external power supply may or may not provide such isolation. If it does, a good one can have lower noise than the battery. No simple answers, I'm afraid.