575W & 750W Source 4

[jmac]

What is the difference between the two (besides the nameplate sticker)? Is it just the cap and lamp socket, or are the housing and lens tube also different? I have some lens tubes that say "Rev. G", and some that are blank. Are there big differences between generations of lens tubes? Are these ok with 750's? Thanks.

[icewolf08]

The guts of the fixture are the same. The early 575W fixtures cannot natively accept a 750W lamp. However, you can get the retrofit kits and install them (along with a new lamp base) and then there is no reason that you can't use 750W lamps in them. The Rev.G lenses i believe are the newest revision, but there is no reason that you can't use an older lens in a newer fixture and vise-versa.

[Nate1714]

Originally Posted by icewolf08

The guts of the fixture are the same. The early 575W fixtures cannot natively accept a 750W lamp. However, you can get the retrofit kits and install them (along with a new lamp base) and then there is no reason that you can't use 750W lamps in them. The Rev.G lenses i believe are the newest revision, but there is no reason that you can't use an older lens in a newer fixture and vise-versa.

Icewolf is correct.

[jmabray]

Usually the difference between the rev's is some small manufacturing change. nothing that would affect fixture performance, just something that might make it easier to manufacture.

I believe that the main differences between the original 575 watt and newer 750 watt fixtures are a) the ability to actually accept the 750 watt lamp (with the third pin) and b) the rating of the wire running from the cap to the connector.

[ship]

When the origional 575w S-4 Leko came out it had some alignment keyways sticking up which needed to be ground away to accept the cap of the 750w cap.

A week ago I was working on some City Theatrical S-4 follow spot fixtures that never got upgraded and made the mistake (wifie yelled about in now being useless as a pineapple now needing to replace) taking away both the four keyways and the coaxial alignment slots. Give me a break... been like ten years since the last time I did the upgrade and I was only helping more efficiently remove what one of her kids was in my area attempting to remove - already cut half way thru the thing in her not telling him sufficient that he would understand what to remove of them keyways...


Remove in grinding down the four little keyways at four out of six points on a clock and leave alone the 3:00 and 9:00 wider ones.

Beyond that the only major difference between a 575w and 750w fixture beyond the holes for the 750w lamp is in the lamp cap to the fixture. The 575w fixture will be wired with 18ga. and the 750w fixture is wired with 16ga wire. At no point unless the wire feeding the fixture is changed should you remove that pin on the lamp and even than that's bad practice to remove the little roll pin on the lamp as you never know after that what fixture such a lamp will show up in.

Can modify the body of the fixture but often cheaper and easier to replace the entire cap assembly.

[jmac]

Thanks all, for confirming the differences.