Balanced headphone connections carry left and right as independent pairs — four conductors, no shared ground return. Three plugs dominate, and they are not equal.
4.4 mm Pentaconn (JEITA) is the modern standard: five contacts, solid mechanics, one agreed pinout (T = L+, R1 = L−, R2 = R+, R3 = R−). The sleeve is chassis ground only — never audio. Portable players and desktop amps have converged here, and it is the balanced end we fit most.
4-pin XLR is the desktop classic: pin 1 = L+, 2 = L−, 3 = R+, 4 = R−, latching shell, impossible to insert wrong. If your amp has the socket, it is the most robust choice there is.
2.5 mm TRRS is the one to treat carefully: two incompatible wiring conventions circulated (HiFiMan/FiiO vs Astell&Kern), the barrel is fragile, and a wrong assumption means swapped channels — or a shorted amp output. We build 2.5 mm on request, but we confirm the target device every single time, and so should you.
Every connector we sell lists its pinout in the spec table. Check it before soldering; ask the shop if anything looks off.
