I drive mine without an amp/DAC, and they sound great to me. I've had some people vigorously tell me that I need a DAC, though. With regards to custom/non-custom, I ran non-custom for 4ish years, and they were good, but customs are a lot more convenient. Perfect seal every time, no need to replace tips when they wear out, no wear-in period on new tips, more solid build quality. I would say it's worth the extra money.
2/26/15 at 11:56pm