Dumb question......why do you need a preamp?

Whether to use a pre or not is a hotly debated issue. I think this is a result of improper impedance matching between pre and power amps and the quality of the DAC analog stage. I use a MSB Reference DAC which has an additional analog input which I use with my Phono pre. I had a VAC sig preamp originally but sold it when I compared the SQ to the Reference alone. As others have said Dealers push Preamps to increase sales.

For high fidelity purposes,

Line stage, dac’s output stage, phono stage should all be in one box on its own with very short internal signal paths and no cables. Power amp should be in a separate box on its own, i.e., if executed well, 2 boxes should be all you need.

Keeping a separate preamp box and running wires to it from a dac or phono box doesn’t always give the best results. Wire made of dragon scales and fairy dust is still not good. An "integrated" amp, i.e. line stage and power amp in the same box doesn’t always give the best results.

An integrated can be enough. It depends on what you want and your budget. Generally speaking you’ll get more out of separates. 

RE: active vs. passive - I’d like counter that a passive “preamp” can be better. It sure has been a revelation in my system. (Although, I’m curious about trying a different active at some point.)

Food for thought.

Ref.: https://www.stereophile.com/content/brilliant-corners-13-emia-remote-autoformer-and-listening-master-jazzman-jerome-sabbagh

An integrated can be good if you want to have a pile of gear between your speakers or run long speaker cables.