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/nc3fahr1-0 A Series, 3 pole XLR female receptacle with 6.35mm (1/4in) stereo jack and switching ground contact, vertical PCB mount, http://cherryamericas.com/wp-content/uploads/2014/12/mx_cat.pdf Cherry MX keyswitch 1.50u PCB Cherry MX keyswitch 1.50u Matias/ALPS keyswitch, 2.25u, PCB mount, https://www.neutrik.com/en/product/ncj9fi-v-0 Combo I series, 3 pole male XLR receptacle, grounding: mating connector shell and front panel, vertical PCB mount, retention spring instead of latch, https://www.neutrik.com/en/product/nc3faav1-0 AA Series, 3 pole male XLR receptacle, grounding: separate ground contact to mating connector shell to pin1 and front panel, horizontal.