Below is some photos of a mini- HiFi combo:
Ipad 3G : as all you know, it is a great products, now work as a music source! it can be a music/video player, also a WiFi radio, WiFi player, WiFi TV and such etc
Camera kit: it can transmit the digital music data from the dock of iPad, and output as USB digital music data !
FiiO's E9: it work as a pre amplifier , transmit the USB signal to E7, and amplify the signal from E7 and output to monitor speaker, also it is a decent desktop amp to drive some headphone like HD580, HD600, HD650!
it have adjustable pre output, so it is very useful to some monitor speakers because most active monitor speaker is hard to control the volume ! at the same time, it also provide power to E7!
FiiO's E7: E7 only work as a USB dac, with the build in high quality D/A converter (WM8740), it can provide better SQ than the build in D/A converter in iPad!
It is also a decent monitor speaker which made by a Chinese brand! the SQ is quite goods, maybe 90% of the Genelec's 8030A!
The whole flow of mucis:
Music data in iPad----transmit to audio data in iPad---dock of ipad---camera kit---USB digital music signal-----USB cable ----- dock of E7----PCM2706---WM8740---analog signal---AD8692---line out of E7----ALPS's
potentiometer in E9--- OP2134-- pre out of E9---monitor speakers!