The holy war over mixing “in the box” (inside your computer, in your host DAW) or outboard (using a full mixer, summing mixer, etc.) rages on. But in our opinion, it’s not an one-or-the-other battle. Why choose and limit yourself? You can also mix in the box, but send various tracks to outboard gear for processing. Or Use plug-ins where appropriate, but still send to external hardware and a summing box or mixer.
All DAWs allow you to send signal out of your audio interface into outboard gear and then bring the processed signal back into your DAW. How this is done varies depending on the specific program, but there is usually an I/O plug-in per track, or an I/O window where you can set routings up; you’ll need an audio interface with extra inputs and outputs for connecting your hardware gear, summing box or mixer, and outboard processors. Just configure your key tracks, buses, or even master output to send out of those extra outptus to some tasty outboard gear and gain the benefit of their magic, then re-capture the signal using the extra interface inputs to mix in the high-headroom, instantly recallable digital domain.
This way, you can gain the benefits of outboard processing and/or mixing or summing while retaining the benefits of in-the-box processing and mixing. It’s a total win-win approach to audio production!