Support USB Audio Interfaces

Could Quad Cortex support external USB audio interfaces? USB class compliant interfaces allow usually up to 24 channels of I/O. AKAI Force does something like this (utilizing some standard Linux libraries) and it works really well.

It also would solve a lot of issues with better integrating Quad Cortex into studio infrastructure as there is interfaces available converting those USB channels then to MADI, ADAT, DANTE or similar.
This would solve a lot of the I/O challenges with Quad Cortex.

And how would they do this? It needs an optical out which it doesn’t have.

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You would just hook up a class compliant audio interface over USB to the Quad Cortex.
It should just be a software update to configure the right Linux open source driver (which already exist)

For example, these type of interfaces work like that on AKAI Force: - Overview - will set 1-24 channels on up to 256 MADI channels via USB class compliant
or - Overview - 4x ADAT - 24 channels I/O via USB class compliant
or - Overview - 4 channels SPDIF plus 4 channels AES plus AVB

Quad Cortex would then act as the host (just like a computer normally connected to the audio interface). To do this, Linux Audio has an open source driver for class compliant USB audio interfaces. The Quad Cortex is running on Linux and uses an ARM processor just like the AKAI Force. That gets the system 24-32 channels of AUDIO I/O over USB2 depending on the audio interface hooked up.

For AKAI Force, it was just a software update to enable this functionality. Originally the AKAI is just an audio interface like Quad Cortex. But with the latest software/firmware updates, you can just hook up any USB class compliant audio interface via USB instead and thanks to the Linux driver, you will then have a massive amount of digital I/O. You would need a USB Type B to Type B cable for the QUAD cortex and Neural DSP would need to include the appropriate Linux driver in their software.

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Yes but they don’t and probably won’t. Not really sure what your point is? At the moment the only way to go from QC to an interface directly is via the normal I/Os on the QC. That’s another layer of A/D conversion.

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The Akai force was specifically designed to be able to have that functionality initially, as it is supposed to be a ‘DAW in a box’.
The QC has no USB input, just a USB output, so this would not be possible via any kind of firmware update.

It also seems rather… pointless?
Both Mac and PC can create and ‘agregate device’ that combines your normal soundcard and the QC to allow you to use all inputs and outputs simultaneously. I do it regularly with the QC and a Focusrite Scarlett, as well as various Elektron synths.

What ‘I/O challenges’ do you have with the QC, because using it for its intended purpose I have had absolutely none. :man_shrugging:

The aggregation on windows sucks and is buggy as hell. For Mac I think is better.

The DI is ok on the QC but id rather use my other one and not have to switch devices all the time.

Whilst I agree the update to the driver is unlikely, it does have a USB input. Otherwise how do you think you reamp?

USB communications are two way, that’s true, however, USB connections are one way. The QC is set up as a peripheral device, so the USB connection is for it to connect to a USB host. The QC cannot act as a host itself and connect other peripheral devices.

It exactly the same as your soundcard - you can’t plug another USB device directly into it and use the two together. (There are potentially some that can if they have a specific USB host connection, but MOST cannot do this).

This is just a feature request so vote for it above if it’s something you would like!

USB B is the exact same port as USB A technically (same pins) and it’s a fully 2-way protocol. The different plugs are only to help not create an accidental loop by users.

Whether the Quad Cortex acts as host or peripheral is solely a software driver thing. AKAI Force was not designed to work as USB audio host at all for years. The software drivers were updated to support this and a setting added in the menu to activate AKAI Force as a audio host. Given this is an existing open source Linux driver and using the same ARM architecture, it should be rather straight forward to add this functionality. Yes, audio interfaces generally do not have a USB host mode. But again that’s a decision if to offer a “host mode” in software or not.

This would be very valuable so its easier to integrate the QC in existing studio architecture. For example, this would allow to pick up or send channels from the existing cables without extra A/D D/A conversion steps. That means less latency, less wiring and easier routing. Many competing multi FX boards offer at least some digital port like S/PDIF, but this would be better than that as with USB2 one should be able to choose from up to 24 channels as source/output via the menus.

Aggregate devices causes latency and other issues. For example, on Windows, we cannot use it at all since ASIO4ALL only supports 2 ports per sound device (besides excessive latency which makes it unusable for tracking).

This^^. However given the time it takes to execute anything at NDSP, it is more likely a feature with the QC 2. Here’s to dreaming zzzz

under-rated and probably under-understood feature request


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Has anyone actually got a USB B to USB B cable? Can you even find one for sale? I can’t.

Also, has anyone tried adding a feature request for the same thing with their audio interface manufacturer?
If I did think this was remotely possible, I would want the QC as the peripheral device since it would be moving in and out of the studio with my audio interface remaining in place.

Type B to Type B cable -

Or 2x
and a USB-C cable

This will require though a software update in Quad Cortex to enable a mode Quad Cortex to act USB host. Yes, you could just disconnect the cable and take the QC on the go.

Fair play. Nothing was coming up for me but I’m in the UK and those are both US Amazon.

So assuming this happens and you have your external soundcard connected to the QC via its USB port…
How are you connecting the QC to the computer?

You would have an audio interface hooked up to the QC that inputs/outputs from/to something like ADAT, MADI, Dante or AVB depending on your studio infrastructure used. Then you just have an audio interface hooked up to the computer that connects to ADAT, MADI, Dante or AVB depending on what you use to access those audio streams.

On Mac, if the audio interface connected to the QC has AVB support, and the Mac is on the same network, the input/output channels would be directly available without a second audio interface. If you use something like UA Apollo, you could simply connect the Apollo ADAT input to the ADAT output from the audio interface (and avoid any D/A, A/D conversion that way).

So your conections would be (ignoring any adat/madi etc for now):

Computer - audio interface - QC ?

If so, then there’s no change to the QC that can/will help. What you need is someone to invent and build a USB Audio Host that will accept multiple USB Audio devices and merge/convert them to be used as one single set of inputs.

Making the QC accept other USB devices as inputs only works to expand the signals you can process within the QC, but in the process totally rules out connecting any other devices digitally.

Not sure what you mean. You need a digital audio connection in your studio like MADI, ADAT, Dante, AVB which I guess are quite common. There is no audio interfaces with 2 USB ports, but it’s also not needed. MacOS e.g. can directly access all the AVB I/O or you just hook up a basic MADI interface to your PC and go that way.

QC accepting a USB audio interface allows you to get I/O from all kind of devices digitally. For example, we have 256 digital audio channels I/O accessible that way via AVB and another 64 via a single MADI stream.

I’m just trying to understand how you are wanting to connect the devices and in what order, so ignoring the protocol for new seemed the easiest way.

The QC has ONE USB port. There are no other non-audio connections apart from MIDI. If another USB device is connected to that port (eg audio interface like a Focusrite Scarlett), then you just have two USB audio devices connected together.
Neither can then connect to a computer, because neither has another digital output. So yes, the audio interface DOES need two USB ports otherwise how is the computer connecting to your QC/interface combo?

If you instead want an audio interface that accepts USB audio from the QC in the same way that the Akai Force can, then this is absolutely nothing to do with the QC at all - I assume this can already work with the Akai Force and anything else similar (if there is anything?).

You can route the audio I/O for example like this:


Where the audio interfaces need to support of course the digital studio infrastructure standard you pick e.g. ADAT.

or e.g. with MAC and AVB:

So in both of those examples, my original point stands: No changes are needed on the QC.

You just need a USB Audio interface that has a USB ‘Output’ (to connect to the computer or “studio infrastructure”) and a USB ‘Input’ to connect to the QC.

Since (I believe) the QC is already class compliant, both of those are absolutely possible IF you can find this magical device that takes USB audio and converts it to ADAT/MADI/Dante/AVB.

EDIT: please let me know if you find that device btw, I have done a lot of searching, and from the look of it, so have many others.

There is a change needed to the QC software. The QC software needs to be able to act as USB host. Otherwise you cannot hook up the USB AUDIO Interface 1, and the whole functionality does not work.
Right now, QC can only work as a “USB audio interface,” but an “interface” needs to hook up to a host.

AKAI Force initially did not support this, but later added a firmware/software change to support this.
USB is always input and output in one connection. But there is “USB hosts” and “USB peripherals.” Audio interfaces are always peripherals.

So all that’s needed is for QC to support the “USB host” mode (which is a software thing).
There is lots of USB interfaces that convert between USB and ADAT/MADI/Dante/AVB, but those interfaces require to be connected to a USB host. Hope that explains it more.