I've currently got a FiiO E17 in a FiiO E09K dock. It's powering my HD650 cans. So far, it's been great. Now that I'm working from home full time, I was thinking of upgrading my setup. Obviously, I'm looking at the D90 and thinking of pairing it with the Monoprice AAA THX 887 and making my own XLR cables and my own balanced headphone cable. Should be fun to do.
I've also been subbing to ROON and was playing some SACD rips that are FLAC 88.2KHz/24bit. The FiiO E17 doesn't understand that rate, and ROON upsamples/oversamples to 96KHz/24bit. Reading the Apos site, it says that the DAC supports up to 32bit/768KHz, but does that include 88.2KHz/24bit? I was considering also adding a Raspberry Pi 4 with the Roopiee XL software as a ROON endpoint. Could be fun! Thanks!