Hi Kevin:
You may know all of this technical stuff, but since you've posted here and others will read it, I'll cover a lot of the "why" below in application, sorry it is lengthy.
As detailed on the TonePack ReadMe file and shown on the video, I'm not using the Fractal on-board VUs. Instead I'm bringing the digital output (via SP/DIF) into a studio console, and I'm targeting -12 db there (but up to -6db for peaks), with humbuckers. This is normally what a FOH person wants to see for solid input signal level, or for recording a track into in a DAW. If you approach zero with the digital output into a console, you'll risk digital distortion or clipping. At -12db you have strong signal, but if need be you can add or take away gain as needed through a DAW, board mixer gain or power amp volume.
So by having everything set to between -12db (and up to -6db for peaks, like with very bassy modern/metal amps), you should not have any Front-oF-House or DAW distortion, and you can use real pedals galore adding gain but avoid clipping.
If your other guitar presets levels are coming in real close to 0 db in a DAW, that can spell trouble. Some pros like Dweezil Zappa even dial their presets to come in even lower like at -20 db -- I kid you not/seen it.
Also as detailed in ReadMe notes and on my blog, there are tips if the presets on your system are coming in too quiet or too loud. But the last thing you want to do is fool with the preset volume level -- the presets are all leveled together.
You will find the amp Level value inside the amp block will range from -24 up to +2 db, because they vary based on the Input Drive and Master volume levels being set, to get the amp to do what it does best. Amp Block Level is the very last control I touch to bring the dialed-in sound up to -12db on each preset. Some amps are far more pickup sensitive or touch sensitive than others too I found; something that is loud with humbuckers may be quiet with single coils. Others are loud with either pickup type, hardly a difference. Some also have better dynamics, others are flattter.
There are other steps you can take first. Here's the relevant
excerpt of that blog post:
Leveling: Every preset was dialed in on Flat Frequency/Flat Response monitors — Atomic Neo-CLRs — at at least 92 db or higher (which is a general standard for film studios for theater goers) or louder, and helps prevent Fletcher Munson effect and making sure the presets work at gig volumes as well as recording into Digital Audio Workstations.
-If you are using an AX8, you should set your output 1 knob to the maximum clockwise – that is unity gain (to the SPDIF signal everything was dialed in on). You can adjust back if need be.
(Interestingly, in 2016 I discovered on the AX8, the front panel Output1 knob actually controls the SPDIF output level too. But on the Axe-Fx XL I use, the SPDIF digital signal appears totally independent -- meaning the Output1 knob has no effect on its level, just the rear XLR outputs. That may have changed since, I did let Fractal know).
-If you are using an XL, your Output 1 knob level should be at roughly noon for unity gain with the digital signal.
Instead of using the XLR outs into my monitors, I instead use the digital SP/DIF output of the signal from my XL (or AX8) into an Universal Apollo Quad console to check my levels (pure digital signal), avoiding a second D/A to A/D conversion or any added gain at Output1. I made sure my SPDIF output unity gain matched the Output 1 setting on my Axe-Fx XL as well.
As a gut check, after dialing everything in on studio monitors in mono, I also then listened to every preset through a third Atomic NEO-CLR with inputs and outputs set to Noon that was 10-12 feet away from me, set up just like I’d use at a local Austin club gig.
Preset levels using humbuckers for most presets have been set to come in between -12db and -6db on most DAW or PA consoles, allowing ample headroom — you should not get any digital clipping (unless you use super-hot active pickups!).
This level setting should also let you use any real-life drive blocks you want in front of the Axe-Fx or AX8 without introducing clipping, but that will be dependent on the output of your own gear.
If you want the presets to sound louder, max your DAW fader, use the gain input or plug-in on your DAW or board, or turn up your stereo monitors, or your power amp feeding your PA or speaker cab — please do those things before fooling with the amp preset level. On an Axe-FX you can turn up Output 1 knob past noon to add more volume to XLR outs.
If you want the presets to sound quieter, then simply turn down the Output1 and/or Output2 knob on your Ax8 or Axe-Fx (if using the XLR outs).
Note that in dialing in the cleans in bank 3, I used a ’68 Telecaster neck pickup. If you use single coils, levels may come in a little softer than humbuckers naturally, but generally the provided drive block in the clean presets is just a “clean boost” and will help bring the preset volume up more — and sound great!
Kevin -- hope this helps! If you want to increase the volume across the board for the presets (like adding 3db), for
Mark II or XLs it is possible using Fractool using the Batch Processor, but
NOT possible for AX8 units. I know, I've tried it -- you can't batch process the amp block level on an AX8, so you'd have to raise the level in another block instead.