Some tips for consistent (hopefully slightly better) "Neural Capture" results

Quad Cortex
1

I’m probably preaching to the choir with some of this but maybe a few folks find it helpful if they’re into “Neural Capture” and aren’t getting good enough results.

May not work for all use-cases but found some of these definitely helped in mine.

Tip #1 :

Before starting the Neural Capture, ensure the input impedance on the instrument is set to what your amp has.

Most amps have a 1Mohm input so getting IN 1 and IN2 to 1M will help (I know if you goin into IN2 with an XLR cable, it makes no difference as the input flips to another value for MIC signals)

Tip #2:

After the “Neural Capture” guide / connection diagram screens, you end up at the point where you can start the Neural Capture process and/or adjust levels.

Do NOT boost the “IN 1 LEVEL” - just leave it as is. Don’t go for peaking at -6dB or any other value - leave it as is.

Bump the IN2 (coming from the Mic or Loadbox) if you need it / the capture to be louder.

Tip #3:

Unless you have a good quality USB cable with ferrite choke between your PC and Quad Cortex (ex: UDG Ultimate USB 2.0 Cable S2BL – Thomann UK), remove the USB cable from the Quad Cortex to the PC.

I was getting some annoying interference / noise that messed my captures & found out by accidentally disconnecting the USB cable while at the Neural Capture screen.

It’s a good idea to have the bare minimum of cables connected to the QC for the Neural Capture process; I’d leave everything else disconnected aside from the stuff you’re told to hook up during the “Connection Diagram” screen.

Tip #4:

For folks using the vanilla (non-IR) Suhr Reactive Load , don’t use the XLR-out on the Suhr to go into the Quad Cortex.

The Suhr RL has a high output impedance (probably too high for the QC’s XLR input to work well with the non-IR Suhr Reactive Load XLR’s output).

Use an unbalanced cable if you’re shooting “direct” / loadbox-only (no cabinet) profiles of your amp if you must (pick a good quality cable like the Sommer LLX stuff).

What I found out last year shooting NAM profiles is that the output transformer on the Suhr hypes the highs and has a sharp attenuation from about 100Hz downward (too sharp for my liking). It does the same thing even if you use the THRU port with a real cab hooked
up.

I got a Behringer GI-100 DI box (very cheap) and connected it between my tube amps and the Suhr Reactive Load for silently shooting direct captures.

The Behringer GI-100 can also go between the amp and a real cab, it’ll apply the impedance curve of the real cab to the capture but the “reamping” phase will not be silent (ie. you’ll hear the alien sounds coming out of the cab :alien:)

Tip #5 : DISREGARD not needed (seems to only affect the output volume!)

NVM

Tip #6:

If noise is still present when you have stuff hooked up, try putting an iso-box like the Palmer PLI-01 or the Palmer PLI-05 between the QC’s “Capture Out” port and the tube amp’s input (or pedal etc - depending on what you’re trying to profile).

I had some pretty aggressive settings on my Ceriatone King Kong 100W where the profiles didn’t turn out as the amp and throwing the PLI-05 in between the QC Capture Out and the Input jack of the Ceriatone helped get good captures.

Sorry for the wall of text but since I got another Quad Cortex recently, Neural Capture was on my mind and wanted to try and apply some lessons learned from the time I sold the first one & moved to exclusively using NAM (neural amp modeler) to profile my gear and present day.

All in all, I like the way the Neural Captures turn out; even the “direct ones” that are shot using a loadbox.

11 Likes
2

Great info, thanks!

Do you know if this would have different results to applying 5.5dB boost to a capture after it’s been saved?

3

I think it’ll be the same but you don’t know how the folks that shot the capture had their levels at the beginning. If you have some captures where you didn’t fiddle with the levels arbitrarily and just left stuff at 0, then yeah - should probably be the same.

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4

Thanks for the recommendations, 2dor. Very well written explanation!

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5

Need to make an edit to Tip #5: it’s not required as it only seems to affect the output level of the output not what’s hitting the profile.

The most important bit for consistency is to leave IN1 level at 0 during the “setup phase” right before starting the capture.

Apologies if it was misleading.

6

I’m confused by this one.

Firstly, the control doesn’t even appear on the capture setup screen, so does the capture process actually depend on this setting at all? Has anyone tried doing two capture of the same device with different settings and compared them?

Secondly, if you’re capturing an amp, the amp input is connected to the Capture Out socket, so surely the QC input impedance wont affect the amp’s input impedance? It might make a difference depending on the output impedance of whatever part of the amp you are connecting to, or to the microphone you are using.

7

It influences the way the end-profile sounds like. I suggested Neural add the impedance selection values at the Neural Capture a while ago but yeah. The QC’s input impedance won’t affect the amp’s input impedance, of course but it will interact with what you’re getting back from the loadbox etc if you’re using an unbalanced cable and how the QC’s input interacts with your guitar DI during the final A/B phase.

8

I don’t see anywhere to make a change to the level/gain after the capture before you save, am i missing something?

9

I can’t remember, it’s been months since I did one.

OP deleted that section though. Best bet is to adjust to taste after the fact, and ‘save as defaults’ so your gain and vol settings are auto-loaded every time.

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10

You can’t. I made a feature request to Neural support to have some additional options at the end of a capture, right before saving it. So far, it hasn’t been done.

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11

I have an original (120w) 5150 and i want to do a direct capture. I also dont want to spend a ton of money on a load box I’ll only use once. The Behringer GI100’s are pretty cheap. Would that work? And would it “soak” enought od the 120w coming from the head. I just want to make sure i dont damage my QC by feeding it a powered line out of the Behringer.

13

Indeed, can use the „output to mixer“ (XLR) output and feed it to the QC.
The DI box doesn’t load the amp so you still have to connect a cabinet to the
„Direct link“ output of the DI box.

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14

what andy says. you won’t fry the qc, but the amp if you don’t load it