I've read about it a million times, I still don't get it. I've read all the guides here and on OCN on audio, you name it, I've read it. Most of it is a bit dated, so it's hard to know if it's still relevant.
I have a Z87X-UD3H motherboard (new haswell system), which uses an ALC898 realtek codec and has a DRV632 600ohm headphone amp. As I understand, impedance really means nothing, it's about sensitivity, who knows what you need, but high impedance means you might not get enough volume, while amps aim to help this and improve audio quality somehow (i dont know how you take something and make it better, doesnt that mean it's just taking it and distorting it? You can't polish a turd, you can't turn bad audio source into good audio, right?).
So in some cases, some headphones, you need an amp, or may want an amp. But you could also use a DAC to improve sound quality instead of an amp. A sound card is just an internal DAC. DACs may have an amp. Or might not. But a DAC, which may or may not have an amp, may or may not have the right plug-ins for your headphones (seriously?), so even if it has an amp, you need a way to plug into the DAC (can you not just mod the inputs? seriously, a headphone line is just 2 wires right?).
So you might want to get a sound card... but for higher impedance phones, you might need an amp too for more volume. But I have a 600 ohm headphone amp on my system. Does that mean that amp is cancelled out if I use a sound card? If I use an external DAC, is it cancelled out?
So instead of going sound card, if I go DAC route.... I gotta get an amp too? Maybe, depending on the phones and DAC of choice? What exactly is the DAC of choice, I dont see any guides on DACs, sound cards, and amps...
Anyways... I'm just unsure how much better it'd make audio, is my solution good enough, would I notice a difference if I went with a sound card or even a nice dac or whatever?