It is actually quite simple. Here is simplified step by step:
On Row 1 - create your preset 1
On Row 2 - create your Preset 2.
Bypass everything on Row 2.
Set your QC to Stomp mode.
Assign everything on Row 1 to Footswitch A in its active state.
Assign everything on Row 2 to the same Footswitch A in “bypass” state.
Test it.
Buy me a beer next time we meet
Got my QC yesterday and inability to toggle presets bothered me. The moment I found that assigning ANY block to toggle on/off state is possible it became obvious.
If I needed to use 2 independent rows as “presets” and alternate between them using a single footswitch, I’d assign a footswitch to toggle the outputs of each row on/off instead of assigning the same footswitch to turn on/off multiple blocks. This gives me the opportunity to use other footswitches to turn on/off other blocks and keep them on/off as I change scenes.
I’ve read somewhere that blocks 1 and 2 share half of QC’s processing power while blocks 3 and 4 share the other half. That said, I’d use rows 1 and 3 for that (which would leave me with rows 2 and 4 for blocks in parallel).
PS: I am new to QC, so I might be wrong. Feel free to correct me.
This method assumes that you’re using a minimal amount of processing–an amp and cab on a single row, plus a small number of other effects that can fit–so that you can switch between rows.
Toggling all of those blocks on and off can help to visualize what is in use, but in terms of sound it’s more important to toggle the output of each signal chain so there’s no noise or bleed going through to the output. On each row you can use a Gain block, with the gain set all the way down, and turn it on when you want to turn the row off.
It gets more complicated when you start adding more effects blocks than can fit on a single row, or when you need to split signals to FOH and a separate power amp and cab setup, or when you want to use the same block for multiple sounds but want to change parameters within it, etc. This is where Scenes become far more useful.
I’m not convinced that the amp-and-cab-on-a-single-row method is the best optimization for the QC’s grid. I just posted about this in a separate thread, give it a look.
EDIT: Yes, @rangelmarcelo, rows 1 & 2 are handled together with half of the QC’s processing power, and 3 & 4 with the other half. If you’re using really CPU-heavy effects everywhere, it’s a good idea to split them up between Rows 1 & 3 instead of 1 & 2. Also, the global EQ is applied with the same processors as rows 1 & 2. If you bog down 1 & 2 too much, the global EQ will not be available to use.
Also, nitpicky detail about QC terminology here: This method only uses 1 preset. A preset can have multiple stomp settings or scenes.
It’s a misnomer to call one stomp setting “Preset 1” and another stomp setting “Preset 2”. For the benefit of the whole user community, don’t call something that is not a preset, a preset.
If this is all happening inside one preset bank, then you are not actually switching presets. You are staying inside one preset and using stomp mode to toggle blocks / params on and off using one foot switch.
It’s the same idea as scene mode without the one foot switch toggling of block states or params. You are changing block states or params inside one preset rather than actually loading a new preset.
