Has anyone tried one of these?

[alternativeroute]

http://www.ebay.co.uk/itm/111402134344?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

100% brand new and high quality
Yamaha digital amplifier chip board Comes with amp function (need to add additional accessories)，beyond TA2024
Voltage range is wide :9-14V
More power, and 4 ohms output 20W
Comes with 4 groups gain mode settings, you can adapt to different sound source
Amplifier board used as the output inductor TDK
The chip comes with amp function (need extra components)
The use of high-speed SMT placement machine, stable performance
Size:8.7x4.9x1.4cm(approx)

What am I missing?

 

[chrisc]

 

[croak]

 

[mahleu]

 

[DeonC]