Mod Duo forgets USB MIDI Keyboard


I played with the mod duo and a usb midi keyboard. I was interrupted and after I came back the mod duo forgot that the midi keyboard was connected. I assume that the usb device got some power savings. Because I can add it again.

How to reproduce

  1. Play with mod duo and usb midi keyboard.
  2. Bake a bread
  3. Try to play with midi keyboard again.

Expected/suggested solution

The configuration shouldn’t change without interaction with me.

Additional information

Open the controller menu (hold left knob down), navigate to Info > Versions and write down here the versions.

  • release: 1.0.4
  • controller: 7497014

Also provide some information about your system if possible.

  • Operating system: Linux
  • System version: Fedora 24

That’s interesting…
So it seems like the MIDI keyboard is entering a powersave mode when left unused for some time?

The MOD does know what devices are being used, but we never added the code to make them automatically re-appear after they get removed.
We kinda have to assume that devices being removed are on purpose. Not sure if there’s a way to differentiate between a real removal and a device powersave mode.

What MIDI keyboard are you using?

I’m using a M-Audio Oxygen 61.

What I have meant was usb autosuspend. There is already a blacklist for mice, usb audio interfaces and other devices that you don’t want them to suspend. I think it must be an udev rule.

But today I think the problem is more difficult. I could reproduce it two times yesterday. But today everything works as you would expect it. I didn’t changed anything from yesterday. I tried connected to the computer and standalone. Do you have any ideas what I could also try to provoke that issue? That definitely shouldn’t happen on stage.

I think I know what it is now. The mod duo gets a small power supply interruption when my adam F5s go into standby or coming out of standby. It’s too short that the mod duo has to reboot but maybe the keyboard doesn’t get enough power.

Sometimes you have bad power supply at concert halls too. Maybe you could prevent that behaviour with something like a timeout? That the mod duo waits for one or two seconds after a device disappears and then deletes it?

Do you know how much power does it need to operate? Does it have option to plug an external power supply or only USB?
Note that MOD USB Host provide limited power to supply devices. If your device has high power consumption you should power it using external adapters.

It’s only powered over USB. I don’t know how much it needs. But I think it’s compliant to usb standard because old versions had an extra power supply.

I plugged the monitors into a power strip with filter now. The problem is gone here. But I really am pro timeout!

I will write to Adam’s support. That shouldn’t happen.

It happened again, when I pressed the sustain pedal.

Something to keep in mind: I had a MIDI controller that would sometimes disconnect and re-connect in < 0.1 of a second. This did mean that ALSA / JACK would see a port dissappear / re-appear, but the connections would not be restored…

I guess I’m saying - does this also happen on a Laptop? Aka: could this be an electrical fault in the keyboard? USB is overload protected, and it cuts the power when overloaded - which causes a USB powered device to reset… and re-appear as normal until it happens again.

Just my experiences - can’t say if that is the actual cause here. -Harry

I will get a meter for this and test it. And I will start to use the keyboard with the laptop. Thanks for the hint.

Hi there!

I’m new to the Mod Duo.
Bought it to use a midi keyboard in live situations stand alone.
I use an Akai MPK mini keyboard.

I have the same problem.
After I remove the cables or power from the Mod Duo and reconnect again it forgets my midi keyboard. It works again when I plug into my laptop, go to the pedalboard and reconnect the connection. Every time I disconnect I have to start my laptop to reconnect the wires in the pedal board.

This way I can’t use it stand-alone.

Does anyone know a solution?
Thanks anyway!

Did you update the firmware? The connection is still unstable but the Mod Duo just reconnects now.

Yes to 1.6.
Is it better in 1.7 now?

1.7 has the “aggregated midi mode” by default, which forces all devices to auto-connect. the “midi ports” button is not even there anymore. this kinda issue wont happen with it anymore. on the web gui all you see is a single midi input and output, the “aggregated” one. all midi devices virtually connect to it.
1.7 is not available as automatic update because this breaks old pedalboards (there might be pedalboards which use multiple midi devices for different things, connecting them separately)

1.8-RC1 has both modes, selectable by pressing “midi ports” button. but 1.8 is still under testing period, for being new (new features added, so just as precaution, we give it 2 weeks of user testing before calling it final)

both versions require manual update.

Thanks, I’ll try 1.7 first!

That worked! Now I like the Mod even more :grinning: