I have a DS Sr and was a USB-to-DAC fan until i realized all the analog noise that USB’s metal-to-metal contact allows to pass from the source (laptop, streamer, etc.) to the DAC. So, go ahead, try regens or intonas or ferrites or cables or $5000 streamers - all this does is attenuate issues or move the problem around to alter the character of the noise.
For my ultimate solution, I went to a new gen USB-to-TOSLINK converter (here) and had my jaw drop to the floor. Glorious optical: zero RF noise seeping from source to DAC. I now hear the DS as it was meant to be heard. So, i’ve sold all my USB gizmos, sold my expensive USB cable and with just mid-grade cables I can play 24/192 TOSLINK all day long with extreme satisfaction. I think this is as good as it can get.