Test and record with a Roland Dou-Capture MK2 Audio interface

[kex]

Hi.

I want to make audio recordings with an audio interface "Roland Duo-capture mk2" (UA-11-MK2). I read, that I have to set a switch "EXT" to "**" at the device and now I can see the device with lsusb:

Code: Select all

$ lsusb
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 064e:9700 Suyin Corp. Asus Integrated Webcam
Bus 001 Device 002: ID 8087:0a2a Intel Corp. 
Bus 001 Device 005: ID 0582:0137 Roland Corp. 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

I don't know, how to proceed now, because I don't know much about, how everything could work together in my system. I tried alsamixer but when I select the device, alsamixer says: "This sound device does not have any controls.

First I would like to test, if I can get some input from my microphone though the audio interface. Second, I want to record the input to an external HDD, see my other posting: viewtopic.php?f=1&p=74010#p74010

[Pablo]

For something simple, but not intuitive, you could use the command "arecord". See "man arecord". Start with "arecord -L" to see the list of devices you can record to, because I don't think the Roland will be the default. See also:
http://www.alsa-project.org/main/index. ... ardTesting
Don't worry about alsamixer, it is useless for your card. Just use the knobs.
Of course, if you execute arecord in a terminal located in your external HDD (/media/...) or you give the file name with the right path, the audio will be recorded right to the external HDD.

Audacity can also record via pure alsa.

Another option is using jack. You have to configure it to use the Roland. Use Cadence for that, as you said you have KXStudio.
There are a number of jack-aware recorders. From command line jack_capture to professional multitrack recorder ardour, you have many options.

Cheers, Pablo

[kex]

Thank you for your help. I could get it run with jack. Do you know, where ardour stored the data? If I start a session locatd at /media/..., will it store the recorded bits there, before it will encode it into the final file format (or however that works)?

[Pablo]

If I start a session locatd at /media/..., will it store the recorded bits there, before it will encode it into the final file format (or however that works)?

Yes. Browse the ardour session folder and you will see there is subfolder called "interchange" with audio files in it. All of these are under /media/..., where your external HDD is "mounted". Ardour doesn't encode to a special audio format or anything. The ardour session file is just text with the relevant information, take a look. Of course, ardour can export a mix (or just a track) to a new audio file (which by default will be located under the "export" subfolder)

[kex]

Thank you. Yes, it works! I still have one problem: The input from the microphone is very, very low. For testing I have the microphone from our camera plugged in. When I add an amplifier plugin to the audio track and increase the volume, the noise is too high. The slide control at the devise is at maximum, the mic is plugged into the mic/guitar input and I tried also all switches (Hi-Z and Input Gain). How can I fix this? What could be a reason for that?

[Pablo]

Maybe you need a preamp to boost the mic signal?
Or it could be that the linux driver needs an adjustment for that particular card. What they call a "quirk". Have you tried the card in windows and does it work as you expect?
If so, I suggest you contact the alsa developers (the people who writes the audio drivers for Linux). They will need the terminal output of "lsusb -v" for that device.

[sadko4u]

I think you should adjust the gain of the audio input to get better loudness.
Try to do it with alsamixer (Key F3 displays outputs, key F4 displays inputs and their gains).

[kex]

The "sound card" is an usb audio interface and as said before, it is not controllable with alsamixer. When I add an amp in ardour, the noise is too loud.

[Pablo]

As I wrote before, it could be that the driver needs a quirk or something but, in any case, connecting a mic directly to this audio interface is not the best option. You should try using an analog preamplifier (or a small mixing console which does the same job).