Demo of PAM8610 Class D Amplifier Boards with electric guitar running into a WGS ET65 12" 8 ohm speaker. Running off Mooer 9V 2000mA switchmode power supply. More info here:
http://jameslow.com/2015/12/12/9v-5-10w-diy-guitar-amp-pam8610-class-d-amplifier-board/
eBay:
http://www.ebay.com/sch/i.html?_nkw=pam8610