I think "It depends" on how you intend to use your system. You can:
- set your presets and scene volumes to be below 0 dB with the guitar's volume at 10, with solo boosts pushing it back to 0 dB. That boost could be built into the scene, or assigned to a CS, it doesn't really matter what mechanism you use to raise the volume.
- set your presets and scene volumes to be 0 dB normally with the guitar's volume at 10, and have a dedicated solo boost using the same mechanism, and temporarily have the overall level run at whatever increased volume you need.
- set your presets and scenes to be 0 dB with the guitar's volume at 10 as you set the levels, then during the performance roll the guitar's volume back to 3-5, and roll that volume up when you solo, similar to what we'd do with a single-channel amp.
There are other variations on the theme, and I have my presets set like the second method, but actually use the third because my 0 dB is plenty loud. And I like single-channel amps.
This is what I think is important…
If you are sending a signal to FOH and have a dedicated FOH engineer then tell them you're going to have solo boosts of
n dB. If you don't say something, not knowing that, the engineer will probably adjust your signal to be 0 dB-ish to match the rest of the band, then react when your solo raises the level, either by hitting your signal with a limiter or by pulling you down in the mix, thinking you got exuberant, and then not notice you dropped down afterward, then you are under the mix the rest of the time by that
n value. So communicate with them so they can expect periodic increases in your level and not freak out thinking that it's the start of a volume war on stage. If the engineer works with the band regularly, they might even prefer to control your solo boosts, so, again, talk to them. Communicating makes you look professional and debonair and the chicks will think you have a great smile. Not communicating it will make the FOH engineer hate you and he'll hit on the chicks who then won't notice your smile. If the band manages their own FOH feed it's not as constraining and the chicks will be at the club with the dedicated FOH guy.
Fractal has a liberal clean zone above 0 dB so you can boost above 0, but there's no real good reason to live above that point continuously. Run at 0 dB and use the OUT knobs on the front panel to control what you're sending out of the modeler. Provide a decent signal to the downstream equipment to help keep the signal-to-noise reduced and you'll be good. And make sure your global settings for the modeler's Out are configured as you need based on the scenario on stage and with FOH.
And, if you're like the rest of us, you'll try multiple ways of managing the solo boost until you find one that makes sense to you while you're playing. There's no "right way" though, just what's right for you.
