Hotshot, if the locos you are referring to are DC only you can run them with the Zephyr without the need of a DC power pack but I wouldn't run them for long as the performance will be less than stellar and long term operation could prove harmful to their motors. It's an issue of the "type" of power that a DCC controller uses verses DC. They will also make a very annoying sound as they operate, again due to the DCC power.
Best to just get a DC power pack to test them with. This way you won't risk damaging a DC loco running them with a DCC power pack. If they are decoder equipped, use the Zephyr.
There is a way to wire DC power packs to the jump ports on the Zephyr and they are intended as an extra DCC throttle. Up to two can be used in this manner but you should read your owners manual for all the details.