Originally Posted by mikeaj
I don't think the LX has a real headphone amplifier.
LOL, okay then...
I wonder how it amplifies his music, and drives his headphones?
Originally Posted by autumnholy
low impedance buffer... err, what does it mean?
So having an amp can lower distortion, and using digital volume control may distort sound signals right?
A "buffer" means what I said earlier, that it has a fixed gain/volume. It was designed to be paired with an external amplifier with a dedicated volume control. It is made to drive up to "line level" which is a standard voltage/current typically sent between stereo components (e.g. a DAC into an amp).
However, a headphone out can also be used to send line levels: http://www.sweetwater.com/expert-center/techtips/d--10/26/2000
Maybe you have plugged in your ipod into a car stereo or speaker setup through its headphone out? This is the same thing.
Now what you are talking about is doing the opposite: using a line level to drive a pair of headphones. Usually the difference is that line level outs have very high impedances (sometimes thousands of ohms), much too high for most headphones. However the DACport LX has only 10 ohms, which is exactly why they call it a low impedance buffer. It just so happens that a low output impedance is a requirement to be a decent headphone amp, since most headphones don't have that high of an impedance. Thus, you're DACport LX can drive headphones.
If you're DACport LX was distorting or coloring the sound, I don't see how putting an amp in front of it would fix anything. It might make it worse..
Some people in this thread think the LX actually sounds better without an external amp: http://www.head-fi.org/t/615548/do-the-dacport-and-the-dacport-lx-really-sound-different
This is due to the volume potentiometer adding flaws in the signal, or something like that.
Anyways, if you really want to put your mind at ease, borrow an amp or buy a cheap cmoy or FiiO and see if you like it more. Do a blind listening test with the volume levels matched as best you can.
Edited by Eisenhower - 9/18/12 at 12:52am