I have other DACs for other purposes, but I just acquired the Audeze iOS Lightning cable for the EL-8 cans, which contains a built-in DAC and headphone amplifier. A very neat device, much less messy than a daisy chain of adapters and dongles.
$100 on top of the EL-8s, but it’s only for the EL-8s, no other cans, not even other Audezes.
First impression is that it sounds great. I will do some more comparisons.
Of course, this doesn’t work well with Roon since the Roon iOS app is not an endpoint. @Brian has explained the technical issues, I hope they get resolved soon. In the meantime I’m testing with Tidal.