ASUS Sound Card Xonar U5
StarTech.com USB Stereo Audio Adapter External Sound Card with SPDIF Digital Audio Out USB Sound Card Adapter ICUSBAUDIO2D
Vantec USB to Serial Adapter (CB-USB20SR)
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Sound Blaster X3 Hi-Res External USB DAC and Amp Sound Card with Super X-Fi Holographic Audio, 7.1 Discrete Surround and Dolby Digital Live with Line-in and Optical-Out for PC and Mac
Creative Sound BlasterX G1 7.1 Portable HD Gaming USB DAC and Sound Card (70SB171000000)
Manhattan High-Speed USB 3-D Sound Adapter (150859)
Vantec 3.5" SATA 6 Gb/s to USB 3.1 Gen II Type-A HDD Enclosure (NST-370A31-BK)
Sound BlasterX G6