Yup, sound card to headphone amp to headphones
Let me give you an example
I have a $20 pair of Sony MDR-cd180's....nothing special, but they wrap around your whole ear and have a decently big diaphragm.
I have it hooked up to my SB Live value, and they sound pretty decent.
When I had them hooked up to my speaker output on my SB 64 AWE (ISA), they had increadible bass that rattled the inside of my eardrum, and they were loud and CLEAN