DDS signal generator for AM

So I've been thinking about making an AM transmitter and I though of a possible very cheap (but still quality) way to do it. There are these very cheap DDS signal generators on ebay for generating arbitrary waveforms. None of them seem to have the ability to use modulation, but they all have a pot for amplitude adjustment. Do you think it would be possible to remove the pot and use an external audio source to make it into an AM transmitter? I'm figuring the audio may need to be amplified or reduced to the right level, but it should work, right? The one I checked says it has "rise and fall time" of 100ns which should be fast enough to use AM.

Here are some links:
http://www.ebay.com/itm/DDS-Functio...131003132420&rk=1&rkt=6&sd=181365844052&rt=nc

http://www.ebay.com/itm/New-8MHz-DD...571?pt=LH_DefaultDomain_0&hash=item4179c767a3