Yes the adapters have resistors built into them, that cut the power from 48V to ~8V, which is optimal for the series. Makes them go for a pretty penny, ~$90 a piece.
For those wanting the super cheap, ebay 406x's, just wait until a broadway show is over, and the dumpster pickers get going again. You may have to scrape the caked on makeup off of them, and they may be a "bit" unmatched, but then again you may luck out.