LOL! Yeah C1998 OT, I fat-fingered that one. Thanks for catching that! That Metro OPT is just killer. It's used in a lot of the Friedman 100watt amps as well. Amp Parts Direct has 100watt Heyboer OPT's, but it doesn't look like they have THAT one. The output leads have a very distinctive cloth type insulation that I don't see in the pics on the APD site.