Got you, well I did burn them in using a New speaker and headphone burn in track for around 25 hours (not at single stretch) at 47 Volume on FiiO X5 3rd gen 2.5mm Balanced output with Turbo mode on. (I know that burn in at higher volumes is bad thanks to Head Fi folks). Today started listening to couple of my favorites with my Amp and just after 1 hour the right ear cup died and there was driver flex on the right side. I ordered all 3 colors Red/Blue/Black all at the same time and same seller, only tested Blue one may be 10 hours of burn in. Now I'm fret that using KZ ZS10s with iFi iDSD BL would be risky.