Num="3" name="C" type="passive"/> Operational amplifier, DIP-8Audio Jack, 2 x switching (normalling) stereo jack and switching ground contact, horizontal PCB mount, https://www.neutrik.com/en/product/nl8md-v STX Series, 4 pole chassis connector, grey D-size flange, mirrored self tapping screw holes (A-screw), vertical PCB mount, https://www.neutrik.com/en/product/nc5mav B Series, 3 pole male XLR receptacle, grounding: separate ground contact to mating connector shell to pin1 and front panel, lateral left PCB mount, https://www.neutrik.com/en/product/ncj9fi-h-0 Combo I series, 3 pole female XLR receptacle, switching contacts, grounding: separate ground contact to mating connector shell to pin1 and front.