- 2 x switching (normalling) stereo jack without switching contact, horizontal PCB mount, https://www.neutrik.com/en/product/nc3mah-0 A Series, 3 pole female XLR receptacle, grounding: separate ground contact to mating connector shell to pin1 and front panel, vertical PCB mount, https://www.neutrik.com/en/product/nl4md-v speakON Chassis Connectors, 4 pole chassis.