This article is still being developed. The information is incomplete and things will change as I flesh out my notes.
Pmod XLR is a project I'm working on that started as a way to connect instruments to a Xilinx 7-series FPGA ADC for DSP, but has since grown into a more advanced platform with:
All the switches in the signal-path are high-quality Omron relays, providing low insertion loss and high fidelity.