This is the PCB of a very low distortion gain module board, making use of Burr Brown's ( now TI ) JFET input, high voltage(+/-24VDC) low noise and high speed opamp OPA2604. The board features two inverting stages cascaded together. The first stage has gain of 20 ( if using the board values) and the second stage serves as a phase inverting buffer( Gain = 1). The output of the two opamps are 180 degree of of phase. This board can be used as : 1. unbalanced to balanced converter with gain with strong driving capability ( good to 600 ohm) ; 2. phase splitter for tube amplifier driving stage ( good to 44Vp-p at supply voltage of +/-24VDC) ; PCB dimension : 48mm x 40mm We do air shipping worldwide at US$4.00.