@imhififan,Thanks for the link and the suggestion. The MBP should run quietest from its battery I would think. if it makes a difference then all I need to do is remember to disconnect the charger when listening to digital files, and more importantly, remember to reconnect it when I'm done! I own several isolation transformers but use only one to isolate my preamp. I found that it works best in this location. Adding additional ISO trannies to other components was detrimental to the sound. Nevertheless I am fascinated by these devices.
Isolation transformer for laptop charger?
Would using an isolation transformer on a MacBook Pro power supply (charger) help to block noise going back into the same circuit which feeds my other audio equipment? The USB output side of the same laptop goes into an ISO Regen with its own linear power supply which then feeds my DAC. I assume the MacBook charger is a SMPS which are known to be very noisy. I'm not an EE so hoping that this isn't a ridiculous question.