For those who have multiple digital audio sources, which output their data via USB --- Do you use some sort of USB Data Switch / Mux, to connect between your sources and DAC(s)? . Is it a commercial product, or something that you assembled? . Do you know whether GND is isolated or common...

The SPDIF/Toslink connector on my PC motherboard has had the little hinged plastic cover come off, and the Toslink cable no longer fits securely. . I'm looking at various PCIe x1 Sound Cards, with SPDIF/Toslink connections, and the more expensive models have EMI Shielding, swap-able Opamps, 600Ω...