Chain of command

The signal source has the MOST affect on sound quality! You can't make a silk purse out of a ...

Power as in your ac lines has the most dramatic effect of everything. Address this first to get the most of everything that is plugged into it starting with your source wether it be ur computer, music server, dac, pre, amp, ect. ect.

You have no idea what you have unleashed sound22card :-)

Not that DACs in phones are "awful", but with the exception of a few LG models (and no doubt others), they are not very good either. There are some good DACs that connect directly to phone USB ports (not the headphone port).

Unless your source is "bad", usually the speakers in combination with the room has the biggest impact on your impression of quality. i.e. great speakers in a well designed room, connected up to a good DAC playing 320kbps MP3 and a reasonably good amplifier, is going to "sound better" than the worlds best DAC and amplifier playing high res audio through poor speakers in a poor room.  This is of course a generality, but for most people will be the case. 


Your impression of quality is usually first, is there something "bad" that irks you, and absent that, it becomes total presentation. Part of the "path" is eliminating really bad things from your system, and those bad things are different for different people. I could play $20,000 wonderfully clear and accurate speakers with an awesome system backing it up to someone who loves deep bass, and if those speakers do not have deep bass, they are going to hate it. Most electronics, even the DAC in your phone are usually not "awful" (emphasis on usually). Speakers can be awful. Cheap turntables can be awful. It's all relative. For many members here, if you said 320kbps MP3 could sound tolerable, they would look at you like you have 4 heads.

How many thumb drives do you have?  Can you put it all on a player like an astell & kern or even a Pono?  Other choice is put it all on micro sd cards (128gb) and put them in the phone.  Use an OTG cable ($5 on Amazon) to a real DAC.  Essentially you will put a ton of music on your phone, use the usb out to a DAC and from there to an amp.

So, essentially, the headphone 'out' of the phone gives me the phone's DAC result, but using an OTG cable, out of the phone's USB will allow a connected DAC to give me it's results....but this is how I access my music (thumbdrive through an OTG into the phone's USB).  I guess what I really need is a DAC that has a USB input, and a screen to view the files on the thumbdrives.
Thanks for the clarifications, folks.