Linsoul Audio: https://www.linsoul.com/
Amazon store: https://goo.gl/zTSUYB
AliExpress Store: https://goo.gl/cDsFTU
After some finagling of the Mk2 (due to the 3.5mm TRRS cable jack), I was able to get the critter up and running. After also burning in the Hibiki Mk2 for well over 30 hours, my initial finding of a fairly weak anemic sound(s) have been alleviated. Using Unique Melody Foam tips, I find the sound fairly full with good resound. Nice, indeed.
And the best combo so far? My Opus #2 hooked to the iBasso PB3. Full, deep reaching bass and with good presence…so far. A nice continuance, after rocky start.