This video explains the R2R resistor ladder and how it can be used to generate analog voltage at a very high Speed. It shows an example synthesizing an 8bit sine wave on a speeker using the Arduino Uno. It is able to generate 3MSamples/s on tha 16MHz clock.
Subsscribe to see some projects in future.
If you have questions, please ask. I do my best to reply all requests.

Music:
_ghost Two Swords
http://ccmixter.org/files/_ghost/26146

Creative Commons Attribution (3.0)
http://creativecommons.org/licenses/b...