i mixed everything through an alesis 16 track recorder (it's a sound interface with a firewire connection) as a sound card, so it standardizes to that. and, i'm using the same amp. but, i was lining it all out in cd-quality through a pair of old sennheisers, not streaming it from bandcamp into a thinkpad running the chrome os.
as far as low quality laptops go, this one is actually not that bad. but, it is what it is.
so, i find that some tracks sound better when you plug the headphones directly into the chromebook, whereas others sound better when i send it into the amp, first. the difference is really mostly about levels, and the bottom line is that the chromebook simply can't produce audio at the right volume. so, when i get simpler mixes, i can tell less, but when i get these saturated mixes, i just need the ponies, and that's all there is to it.
so, it's certainly a lot better through an amp - even with the same headphones, and ultimately using the same line out from the same stream.
i always remind you to use headphones, and you need it to be loud enough to hear it, because i'\m not doing loudness wars shit.