Add note that C12 is optional; not needed if using real TL0x4, fix pots being backwards, tighten up schematic, fit letter instead of latch, https://www.neutrik.com/en/product/nc3faav1-0 AA Series, 3 pole XLR female receptacle with 6.35mm (1/4in) stereo jack, vertical PCB mount, replaces NL4MD-V, NL4MD-V-R, NL4MD-V-S, https://www.neutrik.com/en/product/nl4mdxx-v speakON Chassis Connectors, 4 pole male XLR receptacle, grounding: without ground/shell contact, vertical PCB mount, retention spring instead of latch, https://www.neutrik.com/en/product/nc4fav-0 A Series, 5 pole male XLR receptacle, grounding: separate ground contact to mating connector shell and front panel, steel retention lug, vertical PCB mount, https://www.neutrik.com/en/product/nc3faav1 AA Series, 3 pole female XLR receptacle, grounding: separate ground contact to mating connector shell and front panel, horizontal PCB mount, http://cherryamericas.com/wp-content/uploads/2014/12/mx_cat.pdf Cherry MX keyswitch 2.25u.