Electrical question

@yogiboy 

larger microwave ovens can draw as much as 1500 watts, and these need their own dedicated circuits

Wow!  Every general purpose outlet in Australia is rated at 2400 Watts so that is what most kettles, hair-driers and electric heaters use.  Microwaves are relatively low power devices.

Because we start with sensible voltages (around 240-Volts RMS AC) our current requirements are just a fraction of those in the USA.

All audio components, if they are mains powered, will internally contain regulated DC power supplies and should be immune to minor fluctuations in the AC supply voltage.

A little known fact about microwave ovens is that the magnetron is either on or off.  When a microwave is set for 50% power, the magnetron is switched off half the time.  Usually 20 seconds or so at a time.

Here's what AI says:

In a microwave oven, the duty cycle refers to the ratio of "on" time to the total cycle time of the magnetron, the device that generates microwaves. To achieve lower power settings, microwaves don't actually reduce the magnetron's power output, but rather cycle it on and off at varying intervals. This creates an average power level that is lower than the full power output of the magnetron