I just acquired an Intona filter for my USB line.
My setup already has an ENO ethernet filter connected at the Zen LAN input.
And is this possibly overkill or even detrimental?
You seem to be adding quite a bit of filtering to your system. Perhaps you should try listening to see if they add/detract from the sound? Mind you, I own the Innuos Phoenix USB, so I know that these add-ons can improve sound quality, but stacking them might be asking for trouble.
B