The Mojo is a DAC, with the headphone output taken directly from the DAC.
There is no headphone amp contained within the case - but Mojo does not need one to drive most types of headphones (up to 600 ohms).
Many of us use the Mojo as an input source for a desktop amp, and it performs very well in that role.
If you are looking to drive passive speakers, then you will need to factor in the cost of an amp as well. If budget is an issue, there are pre-owned bargains around on auction sites, or even the ex-demo Yamaha RX-V381 on this page
http://www.son-video.com/destockage...45&utm_medium=email&utm_campaign=Product#DOM3
Some owners of the DAVE dac do drive passive speakers directly from the DAVE, without using an amp, but they do need to be high efficiency speakers.
The Mojo does have less output power, but maybe it is possible to drive desktop monitor type speakers, although I don't remember ever hearing anyone posting about trying this.
Hope this helps.