devices · Quad Cortex · learn · 02 of 10 · 7 min
your first 15 minutes
the one thing
Set the input level before you judge any sound. Every amp model sits after that meter.
power it from the mains, and only the mains
The Quad Cortex needs 12 volts at 3 amps. That is far more current than a typical pedalboard supply delivers on one outlet, so most isolated supplies cannot run it. Check the current rating as well as the voltage. A matching voltage is not enough.
There is no battery option and no USB power. Use the supply in the box until you have specifically confirmed an alternative can deliver 3 A.
It is safe to pull the plug on a running modeler. Neural say so directly, though they still recommend shutting down with the power button first. Cutting power will not corrupt your presets.
Quad Cortex Wiki: FAQthe USB cable is not the one you own
The Quad Cortex uses USB Type B, the big square printer connector, not USB-C. If you also own a Nano Cortex, that cable is USB-C and will not fit.
You do not need USB to make sound, so it will not block your first 15 minutes. You need it for Cortex Control or multi-channel recording.
inputs and outputs
USB
USB Type BMulti-channel audio interface, and the link to Cortex Control on the desktop.
plug in, and pick your output
Guitar into INPUT 1. Then decide where the sound is going, because that changes what you build:
- Headphones or an FRFR speaker: cab block on. The modeled cab does the work of a real one.
- Into a real amp: cab block off, and take the amp block out too. Lesson 07 covers this.
- Front of house: OUT 1/L and OUT 2/R, the balanced XLR pair. That is what the engineer wants.
- A quarter-inch destination: OUT 3/L and OUT 4/R. Mind the cable. A TS cable there costs 6 dB against a TRS one.
set the input level before anything else
Swipe down from the top of the screen, open I/O Settings, and select your input. Watch the IN 1 LEVEL meter while you play a little harder than usual. It should just tickle the red, or sit fractionally below.
Start at 0 dB. The modeler is designed to take a hard-strummed humbucker there without clipping, so for most guitars you are only confirming it. If a hot pickup buries the red, pull the level down until it stops.
This takes 90 seconds. Skip it and what you hear may be your own input clipping, not the amp model.
Input level is global. It is not saved per preset and no scene can change it. Swap between a hot humbucker guitar and a weak single-coil one mid-set and this stage is a compromise for one of them. Set it for the hottest guitar you will play.
Quad Cortex Wiki: Gain Staging · Quad Cortex Wiki: Setting the Input Levelinput level
How to get hereSwipe down from the top of the screen, tap I/O Settings, then select INPUT 1.
1. IN 1 LEVEL—start at 0.0 dB
This is the default and it is correct for most guitars. Neural build the input to take a hard-strummed humbucker here without clipping, so for many players this screen needs no change. Only move it if step 3 says to.
2. the meter: play, don't guess
Play a little harder than usual: a bit above your real playing, short of your hardest. The input stage has to handle that level all night.
3. aim to just tickle the red
Peaks should touch the top of the amber and barely graze the red. That is “just below clipping”, the check that follows 0.0 dB.
4. buried in the red? Come down
If a hard strum sits inside the red instead of grazing it, lower IN 1 LEVEL until it stops. Digital clipping does not soften the way analog clipping does.
5. this setting is global
It is not saved per preset and no scene can change it. Set it for the hottest guitar you will play, then make up the difference on quieter guitars with a gain block inside the presets that need it.
find a sound and a tuner
Presets live in setlists. Start with the Factory setlist. BANK UP and BANK DOWN move through banks, and A to H select within one.
Hold TEMPO for the tuner. HOLD: TUNER is printed on the chassis, so you can find it again without a manual.