Explaining the use of the RCA Plug (Phono) / BNC Connector
The RCA/Phono Plug was first introduced into Europe with the advent of separate phonograph players (i.e. record players) when these were first manufactured as separates, the amps required an RCA (Phono) input which was of course labelled phonograph; due to space restrictions on the amps this was soon shortened to Phono. Hence we commonly know this connector as a Phono but the rest of world call this connector an RCA.
The Professional market required a more robust and lockable connector hence the introduction of the push and twist BNC Connector. Again the BNC is as versatile as the Phono Connector and can be used in exactly the same way or mixed with Phono's (i.e. 1 Phono plug to 1 BNC)
The RCA (Phono) and BNC are versatile single signal carriers - which can be used for any type of voltage signal, providing the cable entry to the plug is sufficient for the type of cable required to carry the individual signal. Within the normal sphere of AV Cables a 4mm or 6mm cable entry is all that is used.
The RCA (Phono) or BNC can be used for the following common signals:-
Mono Audio
1 Phono
Stereo Audio
2 Phono
Digital Audio (SPDIF)
1 Phono (*Note: cable should be at least 75 Ohms)
Composite Video
1 Phono Picture Only
RGB
4 Phono (Red, Green, Blue & Composite Sync)
Component
3 Phono
The original nickel RCA's (Phono's) and BNC's although adequate, loses a small amount of the voltage from the signal being transferred. Gold plating the plug(s) guarantees a superior transfer of the signal; therefore Gold Interconnects are recommended for any home cinema or audio set up.
Today all the Home Cinema and up market AV Cables and AV Leads, offer Gold Phono Plugs and Gold BNC Connectors as standard.
