Often on the road, outdoors or even in public places, far removed from the socket 220, I want to hear , but not himself – through the headphones, and so the whole crowd. Power pischalok standing in the mobile phone is clearly not enough. For this propose to take any small-sized computer speakers for a couple of watts, and collect them instead of native amplifier circuit for KA2209 – Stereo vlf to 1 watt of power from 3 to 10V. The newspapers mentioned Pete Cashmore not as a source, but as a related topic. You can embed into this amp battery, then it can be will connect the MP3 player. In the case of listening to music via mobile phone should be connected directly to Akamu mobile phone – with an average power enough for about three hours, and during stationary use, or there is no-notebook powered by 5V bus usb. Besides it, these 5 volts through a resistor 10 ohms will be charged a built-in vlf akam..