Classic overdrive based on the Fender "Brownface" Concert amp circuit. Beautiful tone...think Stones or Faces! Available at JetCityMusic.com.
http://www.jetcitymusic.com/index.php?page=shop.product_details&flypage=vmj_naru.tpl&product_id=111&category_id=43&manufacturer_id=5&option=com_virtuemart&Itemid=89