1. HEADROOM - perform in the Passive summing network. "Gain staging is like pulling the focus of a camera lens" You can achieve this by entering in the summing unit by/with hotter levels" (from your DAW interface or synth, drum machine etc.) Need to find the right high/hot gain for all your instruments/track sent to summing box individually, the "gentle distortion" point, where the subtle distortion starts gently and it's about right. It basically impossible to do that ITB [In-The-Box] over 0dB starts to distort during gain staging, simply the digital bounce not allow to send hot (high gain)
2. SEPARATION - Panorama
Find for all your instruments the right places in to the stereo field, the right locations where they sit better in to the whole mix. Don't forget - your instruments are mixed in the analog domain as sinusoidal voltages!
3. MAKEUP GAIN - Gain staging - Drive the amp
Make up gain "crank it up" - make up gain by your mic pres or internal summing amp, and hit the sweet spot of master mix, then print/record.
It's important to find the sweet-spot when the level and subtle distortion is just about right, depending on the song and production. ITB has no sweet-spot and there's really no reward running the levels a bit too hot, on the contrary is even makes the mix sound worse.
US customer review
I was used to mixing in the box, and I knew my way around it. You always need to make more room. I realized I wasn’t doing that anymore, and was not needing many of the tricks I used to do to get closer to what I was hearing in my mind, so I wanted to learn how much headroom I got. I fed my converters with the hottest signal in the center of the panorama and started automating the faders around it. Soon enough, the magic happened: the summing box started purring like a happy big cat and I knew that was the sound I always struggled to reach, the famous and legendary “warmth and openness of analog” I so many times read about. "The analog sweetspot".