Multichannel audio interface

Using Arduino Audio
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Hello Arduino community,

and excuse me for being new here... I recently bought an Arduino Uno kit for experimenting so I thought I'd participate.

Anyway, I've had the idea of building a DJ/studio mixer for quite a while and discovered the possibility of using a single-board computer. I've been doing some basic DSP with NI Reaktor (and also with Patchblocks)

Now, I'd like to know whether it's possible (or a good idea anyway..) to route audio i/o from a computer to a mixing console (edit : in a reasonable manner.. a lot of desks do that but building one by hand for this purpose is another thing). I've sort of ditched the idea of a DJ mixer already because of possible compatibility issues with timecode and software. I do see a fine application of using the board for DSP..

I know there are AD/DA converters available. The things that bother me are latency and audio quality.. the price factor will become an issue at some point I'd guess. Also lots of wirework.

Here's the block diagram.. I might've missed a few things as I'm mostly EDM type of guy but I'm after something a bit more classic (I'm obsessed with old school consoles..)

What do you think?

Thanks in advance,

-ef

EDIT : I know there's the Schertler Arthur which is modular and I was extremely interested in it at the time but it doesn't have the connectivity..

EDIT 2 : Basically I designed it so that the channels are solid-state/discrete and connect to the computer via the board... also I'm not sure whether the board is capable of handling the I/O as pictured in the frame but like I said it's a sketch.

EDIT 3 : I'm building a rotary DJ mixer.. you can follow the project in GroupDIY (it has nothing to do with Arduino though)

EDIT 4 : this could also be stripped down to a single channel strip with a USB interface..

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(and also with Patchblocks) ........ I know there's the Schertler Arthur which is modular

Both those links don't work.

The Uno does not have enough memory and is not fast enough to do such a thing. The only thing that might work is a Arduino Zero or a Teensy 3.6. Even so that is pushing it. The Teensy has some DSP software that will do things like mixing and an I2S driver to handle input and output. That is like an A/D and D/A. However a system that has both digital and audio signals is not the the simplest of things to make as the digital system tends to interfere with the audio unless you are very careful.

Have a look at this admittedly long video on the Teensy about the audio capabilities Teensy Audio Library, high quality sound processing in Arduino sketches on Teensy 3.1

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I do see a fine application of using the board for DSP..

The Arduino board? No. Not enough processing power

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Grumpy_Mike:
Both those links don't work.

The Uno does not have enough memory and is not fast enough to do such a thing. The only thing that might work is a Arduino Zero or a Teensy 3.6. Even so that is pushing it. The Teensy has some DSP software that will do things like mixing and an I2S driver to handle input and output. That is like an A/D and D/A. However a system that has both digital and audio signals is not the the simplest of things to make as the digital system tends to interfere with the audio unless you are very careful.

Have a look at this admittedly long video on the Teensy about the audio capabilities Teensy Audio Library, high quality sound processing in Arduino sketches on Teensy 3.1

I've read about the Teensy stuff.. I might have to check it out.

The processing inside the channels (EQ, comp etc if done by the board; digitally that is) is both expensive and takes up a lot of space due to the additional converters (preamps, gain staging, then A/D to processing, then D/A again to the faders)

This inversely also affects the sound quality as the sample rate and bit depth are incrementally decreased in the signal chain... not to mention the loss in headroom (and more latency). I'm also trying to get away with less work by adding the patchbay or some other sort of input matrix (which could lead to more and more work in the end.. go figure)

Also, many audio engineers like the convenience of pre/post-fader sends which requires another routing matrix. Some modular stuff I've seen works with rails that have connectors in them.

Then there's the MIDI thing... which could be appealing for many DAW users (probably just put a MIDI slider next to the normal one..)

There wouldn't probably be much code there to do except for the UI visual feedback. I think one could get away with using an external audio interface but that kind of kills the idea of modularity and the fact that those devices usually show up as separate (some manufacturers have an option to daisy-chain a second unit but that's another thing)

The downside with discrete/analog designs is that they require a lot of soldering...

EDIT : Another thing that worries me now is the frame... wood doesn't quite do justice other than in an application of some padding and leather for a wrist rest or side panels. Aluminium is expensive and requires milling and laser engraving, PVC is prone to all sorts of other problems.

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