Sorry dude, but HiFi audio is a scam. I believe you can hear a difference, but that very difference is not there for the reason you think it is. Trust me. There are so many variables as to why you can hear a difference… Different masters on different platforms, volume normalization, etc. Unless you’re a freaking dolphin, you won’t hear anything beyond 16-bit 44.1kHz. That being said, doesn’t matter of type of file it is, if it’s not low quality, usually it’s going to be played in 16-bit 44.1kHz. There’s no difference between lossy and lossless and between Spotify and any high quality streaming services.

At the end of the day, you’re comparing two different stimuli with countless variables. The only way to do this is: Rip a 320kbps and a lossless file using a good CODEC and isolate all variables, then, perform a blind ABX test (and ask for someone else too). I bet you my life that you won’t be able to tell the difference between a 320kbps source and lossless. Hell, you even have DAC’s that read DSD differently and turn it into PCM after making it DSD again, all of this can affect the perceived sound. All these differences that you claim are easily attributed to placebo and other variables, especially when it comes from a headphone that’s so easy to drive. That DAC “upgrade” didn’t change a thing.

Got the Olina SE as my first decent IEM and it’s my to-go choice when I travel to this day, even though I have the Mest MK2 and the infamous Z1R. I leave the expensive stuff at home and it’s more than enough to have a great experience when i’m far from home or at work. I wouldn’t recommend getting a handful of sub $100-500 IEM’s. You’re just looking at slightly difference sound signatures and personal taste dictates the rest, it’s a waste of money to buy a lot of stuff unless you really feel like doing it for some reason. And what would I recommend? Know what kind of sound signature you like and start to work from there. Don’t get too much stuff. It’s way better to invest in two or even a single very good IEM than having a handful of sub $500 stuff. You’re not gonna have any WOW factor, just different sound signatures. Don’t fall for the consumerism, this hobby is not about it. If you already have the Hexa and the Timeless, you don’t need any more stuff. Maybe just the Kato, but that’s it.

I remember the ones that came with my iPod back in 2007, my trick was push them as close as possible to my ear canal (keeping my fingers on it). That way, they didn’t sound like shit.

OH BOY I SURE DID

Sarcasm apart, Marrantz amp’s are the best. Just got an used SR5006 for ridiculously cheap :D