You’d have to put it all the way around it, including near the connector. Obviously you can’t put it inside the connector, but that’s another avenue for noise to get in. Outisde the box of noise with it’s own box of insulation is a much calmer place.
Miss that era and wish that there were more options for PCI “premium” sound cards. All of the fancy DACs and audio interfaces are seemingly USB.
The inside of the PC is electrically hostile to good sound quality. Loads of electrical noise.
USB is an excellent use of a sound interface.
What if I put foil all around it
You’d have to put it all the way around it, including near the connector. Obviously you can’t put it inside the connector, but that’s another avenue for noise to get in. Outisde the box of noise with it’s own box of insulation is a much calmer place.