Can someone explain Patchbay vs Connections in QJackCtl?

Jack is doing what I want on the Raspberry Pi - audio and midi. But I don’t understand the MIDI bit - could someone point me in the right direction, something to read or a simple explanation if you know it?

Here are the mysteries…

  • If I used Patcbay to connect my midi keyboard to my midi 4-output interface, then I can save the config. But it can only connect keyboard to the first midi port.

  • If I use Connections then I can connect the keyboard to any (or indeed all) of the indiviual midi ports. That’s good, but you can’t save it.

  • Other documentation shows the ‘Connections’ form with Audio/Midi only and the connections are done in the MIDI tab, mine are blank and use ALSA.

Any pointers gratefully received. OK it’s working now, but if I don’t understand it I can’t fix when it breaks tomorrow :smile:

I haven’t used them much myself, but a quick search pointed to this: maybe it’s helpful?

(The article and comments are rather old, but I assume that they’re still mostly accurate :crossed_fingers:)


Thank you @ethancrawford yes not quite the same GUI as I’m seeing, but enough info still relevant to explain why these two forms to do the same thing differently. And how to solve the port selection problem in patchbay.

I still need to hunt down why the connections are in the ALSA tab, and the MIDI tab is empty.

Hope this isn’t seen as too off-topic, it’s all part of using SPi at the heart of a setup.

@ethancrawford interesting ressource !

I think this article may prove useful. Look at the midi section. To be honest I usually just patch in the ALSA section, but this may be a starting point to experiment shifting devices to the jack MIDI section.


Thank you @robin.newman that’s got it!

Using the midi section instead of Alsa, the naming isn’t as good. The midi devices/ports init with generic, numbered names instead of the meaningful names in Alsa. You can rename them manually but mine got out of whack after a reboot. Suspect it uses the connection order to identify them, which can change.

But this is all good, I know where I am now with it.