I use an iPhone 6 (or iPad Air) in this configuration with great results:
iPhone 6 ➟ Apple Lightning to USB 3.0 Adapter ➟ UpTone Audio USB REGEN ➟ dB Audio Labs Tranquility DAC ➟ etc.
The DAC in the iPhone is bypassed with the Adapter. The REGEN does its re-clocking thing and, to my ears, contributes quite a bit to the equation. IMO the resulting sound quality would satisfy many audiophiles.
With virtually no budget limitations the OP is in an enviable position. Separates? Tubes? Balanced? Space constraints?
iPhone 6 ➟ Apple Lightning to USB 3.0 Adapter ➟ UpTone Audio USB REGEN ➟ dB Audio Labs Tranquility DAC ➟ etc.
The DAC in the iPhone is bypassed with the Adapter. The REGEN does its re-clocking thing and, to my ears, contributes quite a bit to the equation. IMO the resulting sound quality would satisfy many audiophiles.
With virtually no budget limitations the OP is in an enviable position. Separates? Tubes? Balanced? Space constraints?