Newbie with an M-Audio Oxygen-25

[crw4096]

Hi,

I've been playing around with Rosegarden, Hydrogen, ZynAddSubFX, amSynth and decided to break down and get a midi keyboard/controller for more fun. But I'm having a lot of problems.

I got it so I could control the knobs and dials in Rosegarden, etc from the keyboard. And I *am* able to get the Oxygen hooked up to amSynth and ZynAddSubFX. But so far not able to get it to play through Rosegarden, or anything else (specifically Qsynth).

And the worst of it is that I'll be messing around playing stuff, and the audio just *dies*. Like the keys stop working. The length of time before this happens is quite variable. The only solution is to power-cycle the Oxygen.

I want to use this with my Ubuntu system (12.04, homebuilt Core i5 desktop), but I did try the unit out with GarageBand on a Mac and didn't notice any problems. Trying to work out if it's a hardware or software issue.

Any clues out there?

Thanks a lot,

Charles

[crw4096]

Does not seem to be the device. Tried it on the Mac with GarageBand for over an hour and never had a problem.

Please let me know if there's a better forum to discuss this issue.

Thanks,

Charles

[Pablo]

What are your jack settings?

And what is the terminal output of

ulimit -r -l

?

[AutoStatic]

And the worst of it is that I'll be messing around playing stuff, and the audio just *dies*.

That's probably the JACK watchdog kicking in because there were too many xruns (JACK couldn't send any audio anymore because the rest of the system responded too slowly).

Like the keys stop working. The length of time before this happens is quite variable. The only solution is to power-cycle the Oxygen.

And after that it works again without having to restart JACK?

I want to use this with my Ubuntu system (12.04, homebuilt Core i5 desktop), but I did try the unit out with GarageBand on a Mac and didn't notice any problems. Trying to work out if it's a hardware or software issue.

Software. The Oxygen 25 should work fine. I have a Oxygen 25 v2 myself and never had any issues with it (until the unit broke down).

[crw4096]

Hi Pablo,

Happy to supply whatever information I can.

$ ulimit -r -l
real-time priority (-r) 0
max locked memory (kbytes, -l) 64

Not sure what this means or what I need. I've been invoking all programs from the xfce menu.

Charles

[crw4096]

And the worst of it is that I'll be messing around playing stuff, and the audio just *dies*.

That's probably the JACK watchdog kicking in because there were too many xruns (JACK couldn't send any audio anymore because the rest of the system responded too slowly).

Like the keys stop working. The length of time before this happens is quite variable. The only solution is to power-cycle the Oxygen.

And after that it works again without having to restart JACK?

I want to use this with my Ubuntu system (12.04, homebuilt Core i5 desktop), but I did try the unit out with GarageBand on a Mac and didn't notice any problems. Trying to work out if it's a hardware or software issue.

Software. The Oxygen 25 should work fine. I have a Oxygen 25 v2 myself and never had any issues with it (until the unit broke down).

I figured it must be software after the unit worked so well with GarageBand But I can't find any troubleshooting info for the low-level stuff. Seems like Linux modules need to be re-initialized or something...

When I power-cycle the unit, there's no need to restart Jack. What I *do* need to do is reconnect the Oxygen 25 to the desired input port. (Under the ALSA tab, select "Oxygen 25 MIDI 1" under the "Readable Clients, then ZynAddSubFX under the "Writable Clients" and click "Connect").

One more bit of information... sometimes the keys will just stick "on". If I mess with it just right, I can get permanent sustain until I click Panic in whatever app. Panic on the KB does nothing...

[crw4096]

Actually, could this be a Linux kernel thing? I'm using the Ubuntu low-latency kernel. Here's the uname -a output:

Linux hostname 3.2.0-23-lowlatency #31-Ubuntu SMP PREEMPT Wed Apr 11 02:24:03 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux

Just wondrin'...

[Pablo]

$ ulimit -r -l
real-time priority (-r) 0
max locked memory (kbytes, -l) 64

This means that you don't have rtprio and memlock privileges. Jack wants that the user has these privileges, otherwise, it won't work properly. Of course, there are other factors that could make the jack audio system fail, but this the first and basic tweak to do.


In recent versions of ubuntu, you can gain said privileges just by adding yourself to the audio group. Just do a:

sudo adduser your_user_name audio

And reboot.

You should now see something like:

Code: Select all

$ ulimit -r -l
real-time priority              (-r) 95
max locked memory       (kbytes, -l) unlimited

Actually, could this be a Linux kernel thing? I'm using the Ubuntu low-latency kernel. Here's the uname -a output:

Linux hostname 3.2.0-23-lowlatency #31-Ubuntu SMP PREEMPT Wed Apr 11 02:24:03 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux

The low-latency kernel helps but you can't use jack reliably without rtprio and memlock privileges.

Cheers! Pablo

[crw4096]

Hey Pablo,

Thanks for that; I definitely wasn't in the audio group. Rebooted, re-logged in, but unfortunately, it doesn't fix the problem!

Audio is otherwise fine. Been composing using the computer keyboard and Rosegarden and never had a problem playing anything. On the other hand, I do still have PulseAudio installed. Should I get rid of it? Is there some interaction with MIDI and PulseAudio?

Charles

[Pablo]

I don't know what happens.

What I would do, I would install qmidiroute which has a MIDI event log, and connect the MIDI keyboard to it in the alsa midi side. Hopefully, you will narrow down the sources of the problem.

[crw4096]

Thanks for the tool tip, Pablo. Unfortunately, the issue exists at a layer lower than qmidiroute can diagnose. qmidiroute is really nice to show all the MIDI messages, and I can see messages for every twist of knob or keypress on the O-25, but then they suddenly stop, along with any music. So it must be below the JACK layer...

Charles

[Pablo]

Have you tried connecting the Oxygen to another USB bus?

You can check what bus is connected to via this command:

lsusb

In general, try to avoid, if possible that:

1) There are other devices in the same USB bus.
2) The USB bus shares IRQ number with a conflictive device. Take a look at "cat /proc/interrupts"

Cheers, Pablo