[LAU] Problems connecting Sound Devices usbpre2 to JACK

Chris Caudle 6807.chris at pop.powweb.com
Fri Apr 23 21:15:01 CEST 2021

On 2021-04-23 13:02, robertlazarski wrote:
> I have two shells open, one with a Jack Session and one with jltcdump. 
> The jack command does change the display on the interface.
> I couldn't get qjackctl to recognize the usb interface, only the 
> default intel sound devices. Audacity doesn't see the device. Any 
> ideas?

Can you describe what you mean by qjackctl won't recognize the 
interface?  The interface is obviously running:

> Shell 1:
> /root> jackd -d alsa -d hw:USBPre2
> Acquire audio card Audio1
> creating alsa driver ... 
> hw:USBPre2|hw:USBPre2|1024|2|48000|0|0|nomon|swmeter|-|32bit
> configuring for 48000Hz, period = 1024 frames (21.3 ms), buffer = 2 
> periods

> Shell #2, does nothing.

You have to connect the audio data from the appropriate channel on the 
interface to jltcdump.  You don't get any connections by default with 
You should see something like system:capture_1 and system:capture_2 
ports, whichever one has the time code signal should be connected to the 
jltcdump port.

Chris Caudle

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