Inputs and outputs
Everything is on the rear — there is nothing on either side of this unit. Click any jack to see what it does and what it costs you.
USB
USB Type BMulti-channel audio interface, and the link to Cortex Control on the desktop.
Type B — the square printer connector, not USB-C. The Nano Cortex uses USB-C, so owning both does not mean owning the right cable. On Windows you also need Neural’s USB Audio Driver installed before Cortex Control will talk to the unit.
Gridleak: read off the unit · Quad Cortex User Manual 4.0.0The cable, the pair, and the supply
USB is Type B
The square printer connector, not USB-C. Owning a Nano Cortex does not mean owning the right cable — that one is USB-C. On Windows you also need Neural's USB Audio Driver before Cortex Control will see the unit at all.
Four outputs means two pairs
OUT 1/L and OUT 2/R are the XLR pair. OUT 3/L and OUT 4/R are the quarter-inch pair. They are not four independent outputs, and a TS cable on the quarter-inch pair halves the voltage — 6 dB you have to add back.
12 V at 3 A is not a pedal supply
Three amps is far more current than most isolated pedalboard supplies deliver on a single outlet. Check the current rating, not just the voltage, before you plan a board around it.
- Set TYPE to Instrument for a guitar
Each combo input has a TYPE switch: Mic for the XLR side, Instrument for the jack side. If it is left on Mic with a guitar plugged in, the sound is thin and wrong and no amount of gain fixes it. This is the first thing to check on a brand-new unit that sounds bad.
Quad Cortex User Manual 4.0.0- There is a GROUND LIFT switch on every input and output
If you have hum or buzz, this is the control for it. It sits in I/O Settings next to the level for each input, each FX return and each output — you do not need a special cable or an adapter.
Quad Cortex User Manual 4.0.0- Input impedance is adjustable, 10 kΩ to 10 MΩ
Only when TYPE is set to Instrument. Lower values load your pickups and soften the top end, higher values keep it bright. Most people never touch it, but it is there if a guitar feels harsh or dull.
Quad Cortex User Manual 4.0.0- Each output has its own level, separate from the volume knob
The VOLUME wheel moves everything at once. In I/O Settings each output has an OUT LEVEL of its own, which is how you send one level to front of house and a different one to your monitor.
Quad Cortex User Manual 4.0.0- Sample rate is fixed at 48 kHz
It cannot be changed. If your session runs at 44.1 or 96, the conversion happens outside the unit.
Quad Cortex Wiki: FAQ- IRs are resampled and truncated on upload
Any WAV at 44.1, 48, 88.2, 96 or 192 kHz is accepted, then converted to 48 kHz and resized to 1,024 samples — about 21 ms. A longer IR does not stay longer.
Quad Cortex Wiki: FAQ- Three jacks have no connection sensing
OUT 1/L, OUT 2/R and CAPTURE OUT never change colour in I/O Settings when something is plugged in. Everything else does.
Quad Cortex Wiki: FAQ
If you plug into OUT 1/L, OUT 2/R or CAPTURE OUT and nothing changes colour in I/O Settings, the unit is fine. Those three jacks have no connection sensing. Every other jack does, which is exactly why their silence reads as a fault.