Audiophiles beware, the other senses are more connected than you think.

[E-Stat]

If you are DBT wires and IC, those are directly interfaced with the multiplexer - and the computer can choose between which input to listen to, single blindly or DB.

How do you eliminate switching transients without sharing grounds? And, if you are comparing interconnects, how do you eliminate the need for a third pigtail?

[Sir Terrence the Terrible]

How do you eliminate switching transients without sharing grounds?

Use a UPS or power conditioner that has isolated grounding. The ones I have provide isolated quality noise suppression,, surge protection, harmonic noise cancellation, and power(voltage) regulation on each plug.

And, if you are comparing interconnects, how do you eliminate the need for a third pigtail?

The custom computer multiplex interface that I have is connected directly to the computer much like a internal sound card. It accommodates all kinds of audio connections, so you don't need a pigtail connection. You plug the IC directly into the multiplexing interface, and program the computer to switch between the interface connections.

I copied this from one pretty darn effective ABX software based test from AES.