An excellent clean guitar amplifier using the TDA7052A chip built for under $10
Buy a 10min Guitar Amp ("Chime Amp") PCB:
http://www.diyguitarpedals.com.au/shop/index.php?main_page=product_info&cPath=1&products_id=84
Punch Amp Forum Thread:
http://www.diystompboxes.com/smfforum/index.php?topic=99271.0