This is a bare board of a high-end, low noise high current headphone amplifier. The circuit is designed around two high performance opamp, LME49710 and BUF03. The board includes on-board power supply and regulator circuit. The board can be used as either headphone amplifier for its high current driving capability, and as preamplifier, for its low noise performance. The board also includes a space that can place the transformer on to make a highly integrated headphone amplifier. The position of LME49710 can be replaced by other single opamp of users preference. We do air shipping worldwide at US$6.00.