@cetla416 , I have the same streamer and Orchid DAC pair (super happy and impressed). Connection is of course USB via a Supra USB cable. For comparison I also have a CDP and phono pre-amp out connected via the RCA inputs. For this test all units' PCs were kept plugged and hot, and the interconnects kept in place mainly for my ease and the simplicity of variables. I cannot confirm without work, all of said components or which if any, share the same power bank and ultimately which outlet on the same wall (same to breaker box though). I ran out of them on same/same and may explain the TT hum. So here us what I observed as far as hums.
The turntable/pre-amp has the most. I think I can run that down (different banks/outlet than amp) but it's not a bother to me as Im about 5% vinyl these days. The CDP/RCA is the least and WAAAY less than the TT. As a reference the volume on my Raven is at 12:00 and takes being pretty close to speaker to hear it.
On to the Zen/Orchid pair. When the Zen is on, and the Orchid is both plugged in and in warmup mode, the hum is the same from the ZEN/USB as the CPD/RCA. Again, way lower than the vinyl. Interestingly, when the Orchid DAC warmup is done and there's an audible click, the hum drops considerably for the RCA/CDP and is really hard to hear without ear in front of speaker. It remains unchanged for the Zen/USB. Using a very sophisticated technique of my phone corner on the baffle between the drivers and some freeware, I get that drop as 57db to 47 db (the house central forced air was also blowing) for the CDP/RCA pairing. Someone smarter than me could perhaps comment on this change at warmup.
So to summarize the hum is acceptable (to me at least) for the Zen/Orchid pair and the CDP/RCA when the Orchid is warming up OR running, but becomes nearly inaudible for the CDP/RCA once it reaches running status. Does this confirm the USB's hum issue and would those filters make the USB circuit as quiet as the RCA's?
Maybe this helps, maybe it confuses the situation. Just a field report from a user with same. Your post and possible cure may ultimately make mine better yet!