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.