How to connect power to a Class D amp board?

Hello, I purchased a class D amp that advertised as taking a 24VDC 10amp input. I was expecting it to come with a 2 terminal power input labelled + and - but instead it is a 3 terminal and labelled VCC GND VCC and there are no instructions. I have attached a picture below. I connected the power supply + to the left VCC and the - to the GND and it powers up and works (and is actually way more powerful then I was expecting). Unfortunately there is a lot of hiss when there is no input. I am trying to figure out what the problem is and so one option I wanted to try was replace the power supply. I do not have another 24V power supply but I do have a couple of 12V. Does anybody have a suggestion of what the purpose of the extra VCC terminal would be? Do you think this is so I could connect one 12V PS between the left VCC and GND and then a second 12V PS between the the right VCC and GND in order to get 24V?

thank you

what amplifier module what that ? sounds interesting ...