[captainclock1988]

Would you mind showing me the exact place where it says "centertapped"?

I didn't say it said that it was center-tapped, I was saying that by the looks of the schematic it looks like its center-tapped. 

But EdHolland answered my question in a much more polite manner.

The output transformer is Tapped but not center-tapped it seems, but the schematic and parts list doesn't specify how the transformer is tapped and what the purpose is of that tap on the output transformer.