Creative Sound Blaster X4 Hi-Res 24bit/192kHz External USB DAC and Amp Sound Card, Super X-Fi, Multi-Channel, 7.1 Discrete Surround, Optical-in, Optical-out, Line-in, Mic-in, Headset-in for PC and Mac : Amazon.co.uk: Computers &
Sound Blaster PLAY! 3 - USB DAC Amp and External Sound Card - Creative Labs (UK)
Sound Blaster X4 - Hi-res 7.1 External USB DAC and Amp Sound Card with Super X-Fi® and SmartComms Kit for PC and Mac - Creative Labs (UK)