USB interface for multi channel outputs, not just stereo

[h4yn0nnym0u5e]

Have you actually selected 8-channel USB in the Tools menu?

If you don't, the AudioInputUSBOct and AudioOutputUSBOct classes are not defined (because they wouldn't work), and that's the error message you'd get.

 

[fan_2021]

I was able to successfully compile.
The issue was I hadn't set the USB Type to "Audio".

I am able to use audacity and stream audio on the first two channels as Audacity only supports stereo playback. Rest of the 6 channels are still silent.

I am looking for an audio tool or audacity plugin that lets to stream 8 channel audio. Any recommendations?

 

[Deftaudio]

You can use Reaper instead and run it in trial mode for what you need.

 

[alex6679]

I am glad that you managed to get it working. Let's hope that 8 channels also work.

 

[h4yn0nnym0u5e]

I am glad that you managed to get it working. Let's hope that 8 channels also work.

Yes, it would be good to have another Mac success. Either way, if you could let us know, and also which Mac hardware and OS you used.

 

[fan_2021]

Hey @alex6679 ,
I noticed that the project doesn't have a license.
Is it possible for you to add a License?

 

[fan_2021]

Yes, it would be good to have another Mac success. Either way, if you could let us know, and also which Mac hardware and OS you used.

I am using MacBook M1 Pro on Sequoia 15.1.1

 

[alex6679]

Good point. I added a MIT license.
Did you already test the usb interface with more than two channels?

 

[fan_2021]

Hey @alex6679,
Yes, I did test it on my Mac.
Even with just Stereo playback with Audacity on Mac.
The channels go Mute after about 5s of playback.Same for more than 8 channel play back as well.

On Windows it works perfectly.

 

[alex6679]

Hi, it looks like the same issue that's occurring on Weiweiweiwear's Mac. A plausible explanation is that it's related to the feedback the Teensy sends to the USB host:

• This would explain why the problem doesn't occur on all Macs—it depends on the clock difference between the USB host and the Teensy.
• It would also explain why it takes a few seconds before the Mac mutes the signal. Initially, the Teensy sends the default feedback and requests samples at 44.1kHz. If the Mac's clock is significantly slower, the Teensy gradually increases the sample request rate to avoid a buffer underflow. Eventually (e.g., after about 5 seconds), the feedback reaches a value that the Mac rejects, and from that point on, the Mac sends only a muted signal.

I’ve created this branch of my usb interface where the Teensy always sends only the default feedback to the USB host. @fan_2021, could you please try this branch and see if the problem still occurs?

 

[rthorntn]

Apologies if this isn't the place to ask.

I have a Teensy 4.1 and a couple of BOOST-DAC8568 dev boards and I was wanting to use this setup for Linux USB audio but I need it to support DC-coupled operation so I can also output control voltages from a DAW. I don't need to use DAC8568, happy to use something more suitable but I would want at least eight DC-coupled channels, is this possible?

Thanks.