Based on Wikipedia and an article on Head-Fi (http://www.head-fi.org/a/explanation-of-amp-pre-amp-headphone-amp), my understanding is that a headphone amp takes a signal (say, from a computer's built in 3.5 mm jack) and amplifies it. This is very helpful for "bigger" or "more demanding" headphones and is a necessity with certain types of headphones.
My IEMs sound fine without an amp and certainly aren't big. Therefore, I've never been interested in amps.
However, I need a DAC that connects by USB to get around hissing noises from my ThinkPad that are somewhat perceptible with a pair of Senneheiser PX100 and are truly awful with Brainwavz IEMs.
I would like to believe that I do not need to get an amp to go along with a DAC based on the following reasoning:
- Tiny IEMs
- A USB-powered DAC provides a bit of power (though not necessarily a ton)
Then: A USB-powered DAC should provide enough power for a pair of IEMs.
Is this reasoning sound?
Let's say that I buy...an ODAC...Is the reasoning still sound?
I'm going to do a little number crunching based on info from Brainwavz and info from Northwest Audio Guy but I'm new to this sort of mathematics so I don't want to use my calculator without a "sanity safety net" in case I screw up.