IMHO, there is a hierarchy when it comes to determining what will make ’our music sound better’.
First and foremost is the source. By far the biggest upgrade you can make in overall sound quality (SQ) is moving from lower bit rate MP3/iTune music download files up to CD playback and/or lossless CD (redbook) quality files. Of course there is an entire world of PCM and DSD file formats that have bit depth and bit rates that exceed even redbook quality, but with these FLAC and AIFF formats, you’ve already hit the point of diminishing returns. Scientific studies have shown that the human ear can’t reliably discern anything above redbook quality, but there are nevertheless an impassioned contingent of audiophiles who will insist otherwise. And then there’s vinyl, as well, but that’s a whole different can of worms.
After the source, the next biggest impact on SQ will come from either your speakers or headphones. Differences here are very easy to discern and again, IMHO, this is where the bulk of your music listening investment should be made. This also the primary area where you can dial in the ‘type’ of sound you prefer. Some folks love reference quality sound, some like a warmer or brighter sound and others are unapologetic bassheads.
Next in the hierarchy is the amplifier. Here as well, very easily discernible differences in SQ can be realized based on the choice of your amplification gear - perhaps not to the same degree of difference that speakers will make, but not too terribly far off. The biggest consideration here is whether to go tubed or solid state.
Only after these first three elements have been adequately addressed would I devote too much attention to the choice of DAC. Certainly differences in SQ can be attributed to increased DAC performance, but you’ll also reach the point of diminishing returns here much more quickly.
Moving beyond the DAC, you’re now starting to get into esoteric considerations like upgraded power supplies, power conditioners, cables and interconnects, etc., etc. Whether there’s anyone on the planet who, in a true double blind comparison, could actually tell the difference between a $200 “audiophile” grade wall outlet versus the one you get at Home Depot for $5, I highly doubt, but if the principles of ROI and the laws of diminishing returns mean nothing to you, I can show you where to find a three foot long USB cable that will only set you back about $1400. ;-)