cyc89 Sorry if I am late with my answer, but I just find this post...
I've been using a Dudu7 7870 unit in a seller-supplied frame in two months now
and I can confirm the unit operates flawlessly in any aspect including the sound system. You have to lower the output level a bit in sound settings in order not to overdrive the amplifier. In exchange you get truly amazing sound quality. but I have to mention I replaced the four door spekers with JBL ones.
And yes, there is a small popping sound at cold bootup, but only then, it does not happen when returning from sleep.