Read this:
solo2 is a single twin tuner - duo2 is 2x twin tuner
solo2 has 512mb of flash - duo2 has 1gb of flash
solo2 has 1gb of ram - duo2 has 2gb of ram
solo2 has 2 usb(usb2.0) - duo 2 has 3 usb(usb2.0)
solo2 is 2.5" sata hdd - duo2 is 2.5 or 3.5" sata hdd
Duo2 also has a 3.2" colour lcd display on the front
Vu Duo2 - Dual core 1.3gz processor, 2gb RAM - 1gb FLASH
As you see on the picture, the STB VUplus Solo2 it´s allinone receiver with tunner onboard incorporated .... you can´t change tunner, cause there aren´t free or slots for that.
Is a TWIN SAT S2 Tunner PVR.
Best regards
nunigaia