Received my zx300a, have been running without a pause for the last 30 hours.
First thing I did with it was compare it to a friends Iphone X from the SE, which it complete floored. No contest at all, clearly not in the same league - we were quite shocked as we did'nt expect that kind of difference.
I've found it excellent with all earbuds I've thrown at it. And below 4.4mm jack I find is really solid quality:
https://www.aliexpress.com/item/Gol...n-Adapter-For-Sony-PHA-2A-TA/32830057812.html
Anyone else using zx300 with earbuds? I find it sounds fantastic with both emx500s (10$ !!) and Willsound mk2 rev2 (40-45$). Both are earbuds with a bit extra bass