At one point in the past ETC changed the Lamp Burner Assembly baffle of the Source Four. (This was around the time of the switch to the 750W fixture.) Over time, ETC has changed suppliers for the Source Four lamp sockets, so they do not all look the same.
The older Source Four Rear Housings (before 1995) had four features protruding up into the burner assembly.
Around 1999 ETC had to fill in the burner post to allow for the ejector pin locations in the casting. As a result, current burners will not fit on the pre-1995 rear housings.
If you have an older (Pre-1997) Source Four fixture and purchase a new lamp socket assembly (ETC Part# 7060B7019 - S4 UL Socket Assy) for the unit, the new sockets may not fit. You will need to purchase a S4 Light Baffle Retrofit Kit (7060A2015). That kit includes the new baffle, a new socket, and several other parts as one complete unit:
Some other Source Four Lamp socket info that is more pertinent to CE versions:
In Europe, S4 sockets are generally the same.
Through the years, we have revised how the socket is built, but the current socket will fit into any S4 750W fixture
In the last few years, we switched suppliers, so that the specific socket may not look exactly the same, but the part number didn’t change, and you can use any of those variants.
1x 7060B7013 is the S4 CE Socket + wires crimped into the socket:
1x M718 was the early S4 UL Socket + wires crimped into the socket (for USA Market, no CE Certificate, and no grounding directly from socket)
After the S4 CE Version came about, M718, became obsolete, and replaced with a new part number 7060B7019.
7060B7019 is now the US Market version of 7060B7013.
7060B7019 cannot be used in the European Market, because it has no CE Certificate.
For the European Market, we sell following sockets for S4 / S4 Jr Fixtures:
7060B7013 --- S4 CE Socket+Cable, 1,5m
7060B7013-L --- S4 CE Socket+Cable, 3m
7060B7013-5M --- S4 CE Socket+Cable, 5m
For the European Market, we sell following sockets for S4 PAR Fixtures:
7061B7001 --- S4 Par CE Socket+Cable, 1,5m
7061B7001-L --- S4 Par CE Socket+Cable, 3m
7061B7001-3M --- S4 Par CE Socket+Cable, 5m