I want to second the Meze 99 Noir. I received mine about two weeks ago and they’re great. My ONLY complaint is the pads get warm. Tried a few pad swaps and I stuck with the larger stock pair.
If you don’t the neutral, mid focused sound of the 58x, these are a great alternate sound signature. No amp required at all.
I own different headphones and amplifiers for listening to different genres of music. The different combinations all have strengths and weaknesses and you should apply them to the music. I do the same for my 2.0 and 2.1 set-ups. The answer to all the above is yes, buy them, as everyone has been kind enough to point out.
In many cases, yes- unless you are amplifying shit. Then, you’re just increasing the amount of shit that hits your ears. You need a clean source. Assuming all things being equal, and we are talking solely about the frequency spectrum that is audible, there is no way to correct distortion with an amp alone.
Also, 3.5 from phone to RCA into amp has the benefit of avoiding hum and grounding issues, if your amp is AC powered and your phone is not charging from AC at the time.
Then, there are some phones with outstanding DACs, considering their portable form factor, and are completely sufficient.
Then, there are some who will argue, “fuck it, it sounds good to me.” To those people- more power to ya.