i just tried a venetian-blind gobo insert in my ETC Leko. it started emitting smoke, and when i pulled it out, i could see that the "blinds" had begun to melt.

i'm using a 750W bulb, and the Leko has "750" stenciled on its side. can i use a bulb of lower wattage, and, if so, does anyone have a recommendation for what wattage i should use to keep from melting the gobo?