Source-Side Plug
Source-Side Plug identifies the plug at the end of the headphone cable that connects to the playback equipment.
Common examples include 3.5 mm or 6.35 mm analogue plugs, balanced headphone plugs, USB-C and Lightning. Electrostatic headphones may use a dedicated energiser connection. This field concerns the source end, separately from any socket or removable cable connector on the earcup.
Source-Side Plug — Headphone
Match the supplied plug to a supported headphone output and the correct electrical arrangement. Diameter alone does not establish the contact wiring: microphone contacts and balanced headphone connections can use different assignments. A digital connection also requires compatible playback support, not merely a matching physical socket.
Check which plugs or adapters are included and whether an alternative is optional. Do not assume an adapter can safely convert every balanced output to an ordinary shared-return headphone connection. The plug identifies a connection format; it does not by itself prove amplifier compatibility, balanced-drive support or better sound.