One of the reasons I'll be returning my unit.I can replicate it by just having the device powered on and plugging/unplugging a 6.36mm cable . It sometimes powers off the device and others it shows a "-5" on the screen before powering off including the pops of course. This happened sometimes even on the 4.4mm jack, I surely informed Topping about it before shipping the amplifier for adjustments.
I prefer benchmark hpa4