https://www.computeraudiophile.com/forums/topic/30593-group-test-usb-gadgets-aq-jitterbug-uptone-reg...
I use an Intona industria galvanic isolator myself. It does several things, but mainly it blocks noise from the computer. It also doesn’t require a power supply. It seems that all the units requiring a power supply do not exhibit their best performance unless used with an optional linear power supply, and these can be very expensive. I’m not certain but because I have 2 femtoclocks on a USB to IS2 board I don't need a unit whose primary function is reclocking, But with generous return policies on many units I may try some others.