I have a power amplifier board on my speaker that has 12v output for the front tone and the karaoke tone board, and I'm gonna cut it off and make it 5v for my hand, okay?

The mobile phone is 5V current 200-2500 mA current, the power amplifier front current is less than 1 amp, 12V is reduced to 5V, the cheap three-end voltage regulator 1805 is also 1 amp maximum to withstand current, can be used, occupying too much is not convenient.