The trick here is that people just think whichever one is loudest sounds best. The iPod might be able to drive high-impedance headphones better than a phone too, since the phone is pretty limited there. You can always get an amp.
But I have this dongle, the exact R&D budget one you discuss, and the iPod side by side with the same song loaded (except the iPhone has way higher resolution, as menitoned the iPod is under 256kbps).
The iPod isn't louder, but it has sounds in the music and a breathiness and real, moving sensation that my recent iPhones with lightning or USB to 3.5 adapters haven't had. It's hard to explain unless you listen side by side, and now I sound like an audiophile but I am far from it - the ears just don't lie and the old iPod really had amazing sound.
That does "sound" like impedance mismatch, which is kind of like an electrical incompatibility with the headphones. The usual effect is low volume but it's not that necessarily. A headphone amp would help.
Try planar magnetic headphones, they're very easy to drive with anything and you'll definitely hear more than you have before. They have a very strange and noticeable "plucked" sound though, like things that are supposed to reverb don't.
The very best and easiest to drive headphones are electrostatic earspeakers which, uh, you can't afford and neither can I. But I have some Stax ones from the 60s with absolutely terrible construction that sound great anyway.
Thanks for the tip and for helping me understand what might be causing this! I wondered if the original iPods had more power output or something.
The headphones in question were cheap Koss Porta Pro Classics, and they appear to have a 60 Ohm impedance. That seems somewhat normal, but would that stand out to you?
If you've never tried the Porta Pros, they're the best bang/buck I've ever found for headphones.
https://www.audiosciencereview.com/forum/index.php?threads/r...
The trick here is that people just think whichever one is loudest sounds best. The iPod might be able to drive high-impedance headphones better than a phone too, since the phone is pretty limited there. You can always get an amp.