You have to be careful since NE5532 is rated for 44V total supply voltage while LM4562 is rated only 34V. It would not work in my Benchmark DAC1 so I used LME49860 (11 of them). It sounds a little better than NE5532 but it depends. Some people praise sound of NE5532. I tried $7.43 OPA1612, that others swear by, and did not like it at all - too bassy and veiled.
LM4562 design won awards for National (including EDN and Electronic Products magazine product of the year awards) but it was for the fact that in spite of being audio amp it has very low offset voltage and drift. It is also more expensive than NE5532 because of that, but if your amp is not directly coupled or uses DC servo then it doesn't matter. I wouldn't also dismiss integrated output stages. Benchmark DAC1 uses integrated power amp BUF34 in headphone amp and sound is excellent. I have small $89 E07K Fiio DAC/amp with integrated output stage and sound with AKG k271 mkII is very good (WM8740+AD8692+TPA6130A). I've also heard good things about Canamp.
LM4562 design won awards for National (including EDN and Electronic Products magazine product of the year awards) but it was for the fact that in spite of being audio amp it has very low offset voltage and drift. It is also more expensive than NE5532 because of that, but if your amp is not directly coupled or uses DC servo then it doesn't matter. I wouldn't also dismiss integrated output stages. Benchmark DAC1 uses integrated power amp BUF34 in headphone amp and sound is excellent. I have small $89 E07K Fiio DAC/amp with integrated output stage and sound with AKG k271 mkII is very good (WM8740+AD8692+TPA6130A). I've also heard good things about Canamp.