I think the previous comments were directed to your post on the LPS-1 drilling, rather than the ER.Actually, connecting a ground cable from ER to the GP-NR of a Shunyata power distributor or Altaira provides a notable improvement in audio quality. Mike Farnsworth, who's a member here, has observed exactly the same thing. And IIRC, stevebythebay has as well.
My experiences with using an Altaira with either my Uptone JS-2 or Cybershaft LPS demonstrated no noticeably better (lower) noise level in the system. And these both have AC grounding via their power receptacles.