On listing is a bare PCB of a well-proven design, which consists of a diamond buffer output stage, preceded by an opamp which defines the voltage gain. Renowned for superb sound quality, the diamond buffer is a well-established topology which has been used in uncountable of commercial designs, in particularly in Marantz's HDAM modules widely applied in their CD players and preamplifiers. This amplifier can be used as the gain stage of a control amplifier, or a headphone amplifier for its excellent current driving capability. This board includes integrated rectifier and dc regulation to make it a very compact preamplifier/headphone amplifier. We provide schematics and part list to buyers by EMAIL. PCB thickness : 1.6mm. Copper thickness : 2 ounce ( 70um -- four times normal copper thickness!) PCB dimension : 81mm x 100mm. We do air shipping worldwide at US$6.00. We welcome combine shipping. Powered by SoldEazy