Connecting Gold Phantom to an amp and/or sub

[bogdan.filipovici]

Roon and a Raspberry Pi with a HAT is also a good solution.

Absolutely! Especially if the OP is already using Roon. Roon's parametric equaliser is very good. REW does not have direct integration with Roon, but it's easy enough to copy EQ values manually.

I am not using Roon. To be honest, this is the first time I'm hearing about Roon and Raspberry (aka the HiFiBerry). I'm playing music from my mac (over the wifi, through sporitfy) and from the phone, through devialet app + spotify