So, I found a couple of master-slave boards online (they’re usually referred to as energy saver power boards) and a couple that indicate they’re switched at about 30-35w of power being consumed by the master device.
In order to buy with certainty, I borrowed a home energy audit kit from my local council, which includes a power meter.
When the amp is turned on it peaks at around 70w for a moment, then settles in at around 43w. With tv a low volume that’s where it stays. With tv at our regular volume it sits around 48w. I suspect the SmartPC must be switched at around 45w. The turn on peak