I've been really smitten with this combo for a good while now.... It's the nicest tripath TA2020 implementation I have heard. Easily bettered my previous Topping TP60 and reputable Amptastic Mini-1 with linear PSU.
The USB implementation is so good that my audiolab q-dac has sat gathering dust since. It's stuck around for headphone duties though, so when a matching M-PWR came up recently I decided to swap things about and start using it's preamp capabilities again.
At twice the RRP q-dac and m-pwr offer a slightly smoother sound but I still miss the speed, detail and rhythm of the kingrex combo - it's a super neat desktop system and sips power too... Minimal heat and maximum efficiency.
In excellent condition, complete with original boxes and stock SMPS should you wish to revert for whatever reason (I wouldn't recommend it).
£220