Soundcard capture + headphone out

Hi all, I’m super excited to try out MODEP but of course I’m having 1 or 2 little issues.

Pi 3 B
Rocksmith guitar cable / USB interface IN

I can get MODEP loaded up and arrange plugins, but there is no output port (Except for midi). I assume there must be a way to arrange things so that we have a soundcard in and audio out through the headphones?

Some things I’ve tried:

speaker-test -dhw:Headphones confirms that the headphone output is working after jack is started (configured for the USB cable of course), and MODEP is up.

Trying to create an alsa output sorta works, but the output doesn’t show up in MODEP, and as soon as I connect effect 0 to alsa out in Patchage, it crashes like so:

patch@patchbox:~ $ alsa_out -d hw:Headphones
selected sample format: 16bit
err = -11
Write error: Resource temporarily unavailable

I’ve tried some variations on starting jack first, then creating the alsa out, then starting MODEP, but so far no luck.

Further, faced with the choice of configuring jack to use headphone or USB input, configuring to use headphone simply doesn’t work no matter the settings (I assume because it’s not a capture device). So therefore I’ve configured to use the USB in, but there seems to be no clear way to configure a separate output.

Ok, I am a fool :smiley: The headphone out is working. I did have to turn the headphone out up in alsamixer. Not sure why I get the unavailable error sometimes.

Follow up question would be if there is some way to automate this setup so that I can boot a pedalboard, and auto-connect it to alsa_out? Hmm…

You should just configure Jack to use the appropriate output.

I have played around with this a little bit, but I can’t quite get it. Any hints?

I’m trying to edit the service definition so jack uses alsa with different capture and playback devices like this:

ExecStart=/etc/jackdrc -t 2000 -R -P 95 -d alsa -C hw:Adapter -P hw:Headphones -r 48000 -p 512 -n 3 -X seq -s -S

Which runs, but MODEP doesn’t recognize any output in the GUI.

I’ll likely pick up a pisound whenever they’re in stock to avoid this, but it would be great to know while I wait.

1 Like

What’s the output of jack_lsp -A while Jack is running?