I've purchased 3 Topping products so far (L30, E30, and PA5), and 2 of them turned out to be defective (L30 and PA5):facepalm: I believe Topping will fix the issue on PA5 eventually, but it's really not a fun experience for early adopters.
I would like to mention to potential buyers of X-SABRE3 that please take a look at this post before making the final decision.
https://www.head-fi.org/threads/new-matrix-audio-x-sabre-3.958851/page-5
A few users (and all X-SABRE 3 users I know of) have complained about a whirring/humming...