Add NAM A2 Capture Support for the Quad Cortex

** Edit: Please upvote this thread again as this was placed in the nano category by mistake, my bad, and the original upvotes are now wasted.


Upvote this request if you want it, thanks. It’s additional support, not asking to replace the existing tech.

I believe this is inevitable now,
multiple manufacturers large & small are working on NAM A2 pedals, eg Fractal.

Their recently released A2 tech blitzed all the proprietary capturing tech in recent vast scientific listening tests,

even their A2-Lite captures, which will run on pedals with $3 embedded chips,
rated higher than V2 Quad Cortex captures.

And now the Genome plugin has come out with NAM A2-powered Parametric Captures,
NAM A2 is the future in my opinion.


I LOVE my Quad Cortex pedal.
But why not have the highest quality possible and most realistic feel?
NAM A2 is basically indistinguishable from the reference amp.

And then you can also use the exact same model for recording via a vst like Genome.

I’m not talking out my arse or being ideological here at all,
observe the posted scientific listening tests below.


There’s a vast library of 250 000 A2 captures available to audition here, via your guitar OR pre-recorded guitar loops.

These new pedals/devices like the Blackstar BEAM Mini include the ability to download directly from Tone3000.

Additional discussion:
[ Please add NAM A2 captures to the Quad Cortex }

I think people are underestimating how hard this is to add to Quad Cortex.

Quad Cortex is not like a normal computer where Neural DSP can just install NAM A2 as a plugin. The audio processing runs inside a very specific real-time DSP system (SHARC). Everything has to be extremely optimized, low-latency and stable.

So even if NAM A2 sounds amazing, adding it to Quad Cortex is not just a matter of building the existing code and running it. NAM’s DSP/inference code would likely need to be adapted, optimized, or partly rewritten for the SHARC architecture used in the QC audio path.

SHARC DSPs are powerful for real-time audio, but they are not desktop CPUs. They have their own constraints and bottlenecks: memory layout, limited fast local memory, DMA/cache behavior, SIMD/vectorization differences, fixed audio block sizes, and very strict real-time deadlines. A neural model that runs fine on a PC, or even on a simple dedicated embedded pedal, does not automatically fit cleanly into an existing multi-block QC preset with amps, cabs, effects, routing, scenes, and low latency.

That is a very different job from PCOM, where Neural DSP are mainly porting their own plugins into their own ecosystem. Supporting NAM A2 would mean integrating an external model format and inference engine into the core DSP platform. That is a much bigger engineering and maintenance problem.

Also, Neural DSP may not need to support NAM A2 directly to get better results. They can use the same kind of data, research, and newer modeling ideas to improve their own capture system. That would probably be easier to integrate and more realistic than turning Quad Cortex into a general NAM host.

I fully support better captures. I just think “add NAM A2” is a much bigger engineering request than it sounds.

If someone specifically wants to use NAM A2 today, they can use a separate pedal or embedded Linux device that supports it and put it in the Quad Cortex effects loop. That is probably the more realistic short-term solution.

But latency still matters. A Linux-based pedal is not automatically bad, but its real-world latency depends heavily on the audio implementation: buffer size, drivers, scheduling, converters, and how optimized the inference engine is. In an effects loop you also add another round of AD/DA conversion, so the total round-trip latency should be checked rather than assumed.

Well said. Part of the reason why it took so long for us to get PCOM is because of the need to convert NDSP’s plug-ins to support the QC’s architecture–not the other way around (converting CorOS to just run a VST).

I keep seeing the argument, “NAM A2 runs on this cheap embedded chip so the Quad Cortex likewise should easily be able to run it” but it’s not a 1:1 comparison.

The QC uses Analog Devices ADSP-SC589 processors that, in addition to the SHARC DSPs have an Arm Cortex-A5 Core. I wonder if it might be relatively easier/simpler/straightforward (in the short term at least) to use the Arm CPU to run NAM A2 captures rather than try to get the SHARC+ DSPs to run it. With how little CPU (at least A2-Lite) needs to run, there might be a lot of headroom on that powerful chip in the QC.

Many Helix units and Fractal FM3/FM9 also use SHARC DSPs. So if they have to appetite to implement NAM A2 support it’ll be interesting to see how long it takes them. That might be a hint at the relative level of effort.

many of the devices that run NAM profiles can only handle the ‘lite’ versions of the captures from what I’ve seen; I have a Mod Devices Dwarf which is an open-end software modeler ‘similar’ to the QC and it can only run dumbed-down versions of the profiles. Not sure NDSP would want to go that route if all it could run is the low-dsp files.

2 ADSP-SC589 in Quad Cortex does have 2 Arm Cortex-A5 cores, but those are not powerful modern application CPUs. They are mainly there for UI, file handling, USB, communication with the DSP side, etc. They are not the part of the system you would normally use for low-latency neural audio inference.

NAM Core is also built around fairly heavy C++/Eigen-style math. Even if A2-Lite is efficient, running that kind of inference reliably on 2 Cortex-A5 cores, inside a live guitar processor, while also handling the rest of the system, is a very different problem from running it on a PC or a dedicated single-purpose pedal.And even if you could make it run, you would still have to move audio between the SHARC DSP and the Arm/Linux side. That means extra buffering and latency.

Vendors like Helix, Fractal FM3/FM9, and even Neural DSP could provide support. All it takes is rewriting NAM and adapting it for SHARC. Source code is available, and it will look exactly like IR Loader. It will be difficult, but generally possible. However, I am completely confident that, based on knowledge of NAM gained from analyzing its source code, it would be easier for Neural DSP improve their own captures.

Great points.

The latency point is quite important. I’d love to see the same blind test, but PLAYING through the modellers. In a real world scenario, I really doubt the audience will care about the difference in sound between line6 proxy and NAM A2-full, or a real tube amp. There’s so much more in between.
Now, the player will surely notice the “feel” when playing through all these different modellers and hardware due to latency, how it reacts, dynamics, etc., and even there, lots of variables in the middle, the cable length, wireless system, distance to the monitors, in-ears …

I’m not saying that QC would be the best of all, I do not know. But would love to see that chart.

Either way, I think that in the end it comes down to what you, as a player, are happier with. And that is much more than if the sound is perceived as 6% better in an controlled test. If you’re happy with NAM great, if it is line6 great, if it is QC great. Just use whatever helps you deliver your best.

That’s out of date, you’re thinking of A1-nano files or A1 converted to some low-res format, and they weren’t worth using IMO.

A2-lite in the current tests ranked just below A2-full and just ahead of QC V2.

A2 only got released at the start of this month, so there’s only a handful of pedal adopters so far, but it will explode I guarantee. It’s a pivotal moment in capture tech and I fully expect to see a Boss A2 pedal at some point. Headrush and Nux have both announced updates that will implement A2 support. Blackstar released the BEAM Mini. It is happening.

A2-full will likely still only be for a few heavy hitters with the required cpu power for now…Anagram, DImehead, Pi-Stomp v3, Fractal etc.

Given the explosion of A2, and the obvious rush to implement A2 support (look at Anagram yesterday and the many others) - NDSP’s failure to adopt this could be the death knell for the system.

Nah, the only folks who really think that are those who are chasing ones and zeros and keeping up with the neighbors. I’d happily buy a Quad Cortex 2 even if it didn’t have NAM support, because Neural have proven their plugins and patches are top class.

I think it’s diminishing returns in terms of tone at this point. What I would like the QC to keep up with/improve is 1) performance: I would love if I could add twice as many V1 or V2 captures or cabs to a single preset, and 2) parametric modeling: captures with realistic knobs instead of just pre-/post-processed snapshots. I am OK with Neural sticking to their proprietary capture technology as far as it does not trail significantly in terms of capabilities and availability. I would much rather be able to have more amps in a preset than have a V3 that sounds 0.5% percent more realistic but eats all the CPU. However, seeing the Two Notes GENOME 2.0 with its AmpNet multi-parametric captures did make me quite interested…

It may not be the death nell for QC, but if these existing and new devices are going to cost a fraction of the cost of a QC with capture tech at least on par if not better than NDSP then I can easily see it the NAM capture ecosystem explode. The ecosystem of devices, plugins, library managers, explosion in the capture community and variety of captures available. That’s what I want on my QC, not really the sound difference in NAM A2.

I don’t care if A2 is better, it doesn’t have to be better, it just has to be ubiquitous. Captures and tools around capturing will be everywhere all working to improve their ecosystem because it’s open. I’d love for my QC to participate in that ecosystem, that landscape of all these new captures, or higher quality captures, or just better organization of captures so I can find a pedal or amp at the settings I want without hunting in Cortex Cloud (or even the current incarnation of Tone 3000). In the last week there were ~135 Cortex Cloud v2 captures, there was over 300 NAM A2 captures created in the same time period. That difference is only going to increase. I don’t use a ton of captures, but when I do I often have a hard time finding that thing I want with similar settings I want. That will get better in the NAM ecosystem.

Also, if A2-Lite uses less DSP/CPU and sound equivalent and that fact that I can fit more capture blocks per CPU/DSP without having to give up something is also a win. NDSP v2 captures definitely use a lot of DSP.

In that world, at QC’s price, the main differentiator is playing NDSP plugins. While that’s great, $1400-$1800 to play NDSP’s plugins and their models is steep when the competition may have an amazing capture ecosystem (and what ever models/effects they bundle in) at less than half that price. If HX Stomp or Helix or some future version of those had NAM V2 tech and lower price points vs QC, I’m not sure I would buy a QC in that world, and I love my QC.

Lets be honest, having more options in the world is a good thing. It drives competition, innovation, and technology. A lot of the things you outlined are fine in their own lane. Neural has a path they’re following and NAM devices have their own.

I understand wanting everything in one unit, but having more tools in the toolbox is more desirable. Heck, I’m still excited for the Amp-X by BluGuitar and that’s kind of a different ballgame.

Maybe for your applications, supplementing or using a different unit altogether might be the right fit? In the end though, how many sounds do we all use on the regular?

Worth noting for folks who are unaware that while AmpNet is another proprietary modelling format, it is based on NAM under the hood. Not a lot of people know this but NAM itself does support parametric models, so it would be very cool to be able to use the QC to create and play parametric NAM captures:

https://www.neuralampmodeler.com/post/the-first-publicly-available-parametric-neural-amp-model

I added a +1 on this feature request because I have a large library of NAM captures that I want to be able to use alongside the QC’s top-tier white/grey-box models and effects with no additional hardware. Having NAM support would make the QC a one-stop shop for me since the only time I am not using NDSP products to practice and record is when I am creating/using NAM captures.

I want to be able to easily create NAM captures with the QC and share them with my friends who don’t have a QC. I can then send them demos with QC effects presets applied and give them FOMO about using their new favorite NAM capture with a QC :stuck_out_tongue: Seriously tho the benefits of being interoperable with this large and growing ecosystem of open source models and players cannot be overstated. Even if it doesn’t happen in the current generation of devices, perhaps the support this request gets can inspire an upgrade in the next generation QC.

This is not going to happen, and I’ll eat my hat if I’m wrong!

But also, I’d be so disappointed if they spent any time working on integrating just another capture tech instead of things people have been actually wanting for years now.

I might be wrong but, aren’t the models included in the QC just that? They had this machine to move knobs and capture it on that state, then they will merge it all together (sorry forgot the name).

I don’t think NeuralDSP would be interested in adopting a competing technology, they’d much prefer to continue evolving their own captures training and methodologies

You are thinking of TINA. Since NDSP models are proprietary, we don’t know how much of their sound is based on data collected by TINA vs how much is “white-box” component modelling. But insofar as their models are using data collected by TINA, yes, that is operating on the same principle as a parametric NAM model: capture the gear at many different settings and let machine learning interpolate the “gaps” between each of the captured settings so that the user doesn’t have to actually create a capture of every single micro-setting on every potentiometer in order to have fairly accurate tones when the pots are set in between the captured settings.

NAM creator Steven Atkinson wrote in that blog post I linked above about how with modern capture methods the parametric capturing process doesn’t need to be roboticized because it can be done with much fewer captures than a naive approach would otherwise suggest:

A related misconception is that it is practically impossible to collect enough data to make a model like this. For a single-knob model (e.g. of the “drive” knob), one could imagine sweeping the knob from 0 to 10 in increments of 1, requiring a total of 11 reamps. With the standard reamping file I’ve provided for NAM, this could be done in under an hour. However, to do this for 2 knobs, one might imagine that they would have to do all combinations of the knobs, making for 11x11=121 reamps. For this model, which has two knobs and two switches, this logic would suggest that I ran almost 500 reamps, recording over 24 hours of audio.

One way around this is to reduce the number of points–instead of increments of 1, I could do increments of 2 (0,2,4,6,8,10) and reduce the number of points by a factor of about 4 overall. But this is a losing game, since adding one more knob multiplies the work by a factor (of 11, or 6, in this example.) With only 2 values per knob (min, max), the 7-knob model above would have still taken over 100 reamps (and might have pretty dubious accuracy interpolating between those extremes!) This challenge has a name: the curse of dimensionality.

Since that’s a really big problem, there’s been a lot of work to fix it, falling largely under the scientific field of optimal experimental design. It’s beyond the scope of this blog post to get into the details, but the punchline is that using some advanced methods from this field allowed me to trim the time I spent (including the time spent moving the knobs between reamps) to just over an hour. Work smarter, not harder!

Of course, an important difference between QC models and NAM is that unlike QC models, NAM is open source, meaning that anyone can build on NAM and NAM models are freely interoperable between different NAM players. So while QC models might be functionally similar to NAM models in some ways in how they work in isolation, their differences quickly become apparent once the user has any desire to use their QC models outside of the QC ecosystem: of course, they can’t, they are stuck using them on the QC hardware with models and effects created by NDSP for that hardware. Whereas NAM is usable in a large variety of different software apps and hardware devices made by dozens of different developers and manufacturers.

I think it is plausible that they could go in the NAM direction, especially if enough users request NAM support. There have already been a few companies that have their own proprietary modeling tech but have also either already added NAM support or said they will in the future e.g. Fractal Audio, Blackstar, Hotone, Tonocracy, Two Notes… so it wouldn’t exactly be unprecedented if NDSP decided to as well.

NAM is already empirically superior to NDSP’s capture technology according to objective metrics such as null tests and more subjective measures such as listening tests. Sure, NDSP could continue waging an arms race against NAM and try to get ahead. Or, they could embrace NAM as an open standard and refocus the bulk* of resources they would have spent fighting the capturing arms race into other lines of work, such as continuing to improve their time-based effects (which NAM cannot model), quality of life improvements across the board, compute optimization, more PCOM support, artist collaborations, etc etc… things that open-source fundamentally cannot improve upon because they are truly unique to the NDSP ecosystem.

* If I were in their shoes I would also make sure to set some slice of those resources aside to invest into continuing to improve the NAM open-source algorithms to ensure that NAM remains the best capturing tech available. Since there is a large and growing ecosystem of companies investing into NAM development already, no single company needs to shoulder that entire burden like they do with proprietary capturing tech, resulting in significantly reduced contributions required from each individual company to achieve comparable (in actuality, even better) results.

Great post! I enjoyed reading that one. Thnx!

You keep forgetting that NAM is a standard embedded RT Linux, not a SHARC+ cores.

For Neural DSP to use NAM without any issues, they would need to re-release their products on embedded RT Linux or spend a lot of time rewriting complex math code for SHARC+. I can assure you that no one in their right mind would do that. They’ll adopt their algorithms, based on NAM, revise it to make their captures either comparable to NAM or even better.

Most of the devices and companies that have announced support for NAM actually use embedded RT Linux. Where to implement NAM, all you need to do is add a call in the code and compile it.

I found this post because I’m planning to redo my pedal board and the QC Mini would be a perfect fit for my plans… but I’m less interested if NAM support is not going happen.

Have Neural made any kind of official statement on the matter, for or against?

I know you shouldn’t buy anything based on a promise, but I’d feel better pulling the trigger on a QC Mini if there was a promise of NAM support in the future.

Just to be clear, this is not about A2 being a superior technology (allegedly) for me, I’m actually perfectly happy with the converted NAM format my current modeller supports, for me it’s more about losing Tone3000 as a resource.

In other words, I’d be happy with support for a converted NAM format on the QC if it’s too hard to implement native support, certainly better than no support at all.

It’d be nice with some clarity on what Neural’s stance is so I have something concrete to base my decision on.