Skip to content
gridleak
Learn
Learn

Your first capture

The safety rule that comes before everything, the hookup for each kind of source, and how to judge whether a capture is any good.

Lesson 08 of 1012 min
The short version

Never send an amp’s speaker output into this pedal. Beyond that: set level carefully, don’t touch anything for five minutes, and expect to take several attempts.

Safety, before anything else

This is the one place on the Nano Cortex where a mistake destroys hardware rather than just sounding bad.

Can damage gear

Never connect a tube amp’s speaker output directly to the Nano Cortex. Neural DSP states this can cause serious damage to both devices. Capturing an amp head requires a reactive load box — a Two Notes Torpedo Captor, Suhr Reactive Load IR, Fryette Power Station, Universal Audio OX or Radial Headload. A ToneX Z-Tone is a DI box, not a load box, and will not protect your amp.

Creating Neural Captures on Nano Cortex · Forum: simulating an FX loop
Can damage gear

If you capture through an amp’s own DI output instead, keep a speaker cabinet connected to the amp. Running a tube amp with no load damages it.

Creating Neural Captures on Nano Cortex

How the routing works

Always the same two jacks: OUTPUT 2R is the send, CAPTURE INPUT is the return. That’s why you lose stereo while capturing — 2R is doing another job.

Press CAPTURE to enter Capture Mode; the ring stays lit while you’re in it.

  • Drive or fuzz pedal: 2R into the pedal’s input, pedal’s output into CAPTURE INPUT. Instrument cables throughout.
  • Combo amp or mic’d cabinet: 2R into the amp’s input, a dynamic microphone into CAPTURE INPUT. Dynamic only — there’s no phantom power.
  • Amp head with a load box: 2R into the amp’s input, the amp’s speaker output into the load box, the load box’s balanced output into CAPTURE INPUT.
  • Amp head via its DI: 2R into the amp’s input, the amp’s DI output into CAPTURE INPUT, cabinet still connected.
  • Preamp only: 2R into the amp’s input, the amp’s FX Send into CAPTURE INPUT. Don’t also patch the FX Return — that’s a feedback loop.

Setting the level

This is where captures succeed or fail. Turn the IR Loader off first, then:

  1. 01Set the target device to exactly the settings you want captured. A capture is a snapshot — whatever the amp is doing now is what you get, forever.
  2. 02Set GAIN to minimum before engaging BOOST. Neural DSP repeats this warning in three separate documents.
  3. 03Play, and watch the GAIN ring. Blue means too low — raise GAIN, or engage the +26 dB BOOST. Green means right. Red or blinking means clipping: lower the source, or disengage BOOST.
  4. 04LEVEL and HP OUT only affect your monitoring. They do not affect capture level.
  5. 05Use the GND switch if you get ground-loop hum from the amp.
Watch out

Green LEDs during calibration do not guarantee success. There’s a separate, stricter sanity check during the capture itself, and owners get “detected level signal was too high” despite a full-green calibration. If that happens, lower the amp’s volume rather than the Nano’s gain, and drop capture gain further even if the meter then reads blue. One owner needed four attempts.

Forum: capture error / level too high

Running it

Hold CAPTURE for three seconds. The ring fills progressively as it runs — that’s your only progress indicator. It takes about five minutes, during which the pedal measures the target’s latency, plays test tones, records the response and trains a neural network on-device.

Do not adjust anything while it runs. Don’t move the microphone, don’t touch the amp, don’t nudge a cable. Neural DSP warns about this explicitly, and it’s the easiest way to waste five minutes.

Wear headphones if you’re capturing a mic’d combo. The calibration sweep is unpleasant to sit next to.

Judging what you got

This is the part every existing tutorial skips. They all teach the button sequence; almost none teach judgement.

Tap Footswitch I to A/B between your new capture (LED green) and the real device (LED off). Listen for three things specifically: does the low end have the same weight, does the top end have the same character rather than just the same brightness, and does it respond the same way when you dig in.

Turn Footswitch II to audition through the IR slots. If you captured a mic’d cabinet, bypass the IR while auditioning — otherwise you’re listening to two speakers.

Craft, not procedure

A few things that separate a good capture from a technically-successful one:

  • Capture the head, not the head and cab, unless you specifically want that microphone sound welded on permanently. This is the biggest quality-of-life decision you’ll make.
  • Neural DSP’s starting point for microphone placement: dynamic mic, 90° to the cone, aimed at the centre, about an inch from the grille. Moving toward the outer edge reduces mids; further back increases room and reduces bass focus; a 45° angle warms it and reduces highs.
  • Capture with the amp’s bass and treble at noon, so the Nano’s tone controls have symmetric room to move afterwards.
  • Passive DI boxes are preferred for lower noise. Owners report good results with a Thomann Millennium DI-E and a Neve RNDI, and mixed-to-poor results with a Behringer Ultra-G.
  • Take several. Premier Guitar found that getting the best approximation can take many tries, particularly with the amp-miking method.

Saving it

Press SAVE — the destination indicators blink. Press BANK to cycle banks, turn Footswitch I to pick the slot, then hold SAVE for three seconds to confirm. Naming and metadata happen in the app.

The position where all five indicators light is the User Library. Save there if you don’t want to occupy a bank slot.

Captures you make are Neural Capture V1. Since NanOS 2.2.0 the Nano can play the higher-resolution V2 captures made on a Quad Cortex, but it cannot create them — V2 creation on the Nano is described as under development.

NanOS 2.2.0 release notes · Nano Cortex FAQ