RME Octamic XTC

Talk about your MIDI interfaces, microphones, keyboards...

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richandrews
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RME Octamic XTC

Post by richandrews »

Supposedly should work as a class compliant device per doc. I've managed to send audio using ALSA, but alsa-mixer doesn't show the capture/send channels and therefore the Octamic XTC will not function as an audio interface.

Maybe someone has had experience reading alsa-info? Mine's attached.

Any advice appreciated!
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tripomatic
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Re: RME Octamic XTC

Post by tripomatic »

Correct me if i'm wrong.

For what i see in the information on the RME website
It"s not an interface, it's AD convertor/Preamp

Communication happens thru Madi of ADAT/AES/EBU to an interface.
Only Midi goes thru usb.

MIDI I/O via DIN, USB (2x) and MADI
4 x AES/EBU out via D-Sub, 8 channels @ 192 kHz
2 x ADAT out, 8 channels @ 96 kHz
MADI I/O (64 channels @ 48 kHz)

On what interface is it connected? You should have an interface with those options above?
richandrews
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Re: RME Octamic XTC

Post by richandrews »

Indeed it is predominantly a preamp style device, but there is the AD conversion and the USB 2.0 Host interface on the back acts as an audio interface.
They say, "USB 2.0: Class Compliant audio interface and firmware update under Windows and Mac OS X.
iPad: Class Compliant audio interface via Camera Connection Kit. ". RME lets MIDI route over MADI or USB, or the physical MIDI connector on the back. This thing really has all the bells and whistles.

lsusb shows the device, ALSA sees two send channels which can be monitored on the Octamic XTC. So that is all great. Just not capture channels.

I'm unsure if this is because ALSA simply needs some config tweaks or if the Octamic XTC CC feature is just not going to work with Linux.

So I'm going to first start with USB Audio and work my way through ALSA, but I severely lack wisdom on this.
richandrews
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Re: RME Octamic XTC

Post by richandrews »

Had a quick chat with RME support. Their expectation is that the Octamic XTC and ASLA should be turnkey. So that is good news which validates the worthiness of trying to get the two working.

Perhaps this is just a "I don't know jack about configuring ALSA" issue. So given the RME claim on CC support, it is time to look into usb audio and ALSA!
Drumfix
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Re: RME Octamic XTC

Post by Drumfix »

First of all i would start qjackctl and select the octamic as the device to use and see how many i/o channels there are over usb.
There should be 24 Ins/Outs

Also a "sudo lsusb -v" would be nice.

I suspect the inputs of the device are initially muted. All configuration of the device including mute/unmute is performed through sysex commands.
See the manual pages 72-75.

Check the name of the Octamic midi port using

amidi -l

then send the sysex commands, e.g. like this (settings for Mic input 1)

amidi -p <name of midi port> -S "f0 00 20 0d 69 00 20 01 00 00 7f f7"

Edit: You can download the RME midi remote software for windows from the RME website and run it using wine.
Edit2: And even simpler: Use the fronpanel controls to make the adjustments.
richandrews
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Re: RME Octamic XTC

Post by richandrews »

Ok, got it!

Key points in my experience (having had no experience):


Incredibly enough... muted channel

Figure it out in two seconds, but yes, the one channel I was using had been muted. The other 7, no... But configuring the XTC is super clear and largely makes sense. And, the muted channel was determined prior to messing with Linux. The XTC has enough bells and whistles to make sure the input channels can be monitored. Verified by placing the mic channel in question on phones 1.


USB

Totally A-Ok - lsusb showed everything - the XTC's USB chip is from "Standard Microsystems Corp". Not sure if 0424:3fda is a vendor or other unique ID.

I have noticed that sometimes the XTC isn't recognized when Linux is reboot, and a unplug/plug back in makes it recognized. Unfortunately, for my application it is crucial that the XTC can always be see on USB. Will cross that bridge later...

Jack is necessary

Somehow, Jack is magically telling ALSA, "Hey, you've got a device and it has channels". ALSA seems to need to be told how to be configured for device capture channels. 'alsamixer' simply reports the device, shows one PCM playback and "This device does not have any capture controls".

When Jack is running the channels can be seen

Playing with qjackctl allows things to be somewhat introspected. And it creates a handy how-to-run jackd CLI in ~/.jackdrc. The RME Octamic XTC needed a bare bones: jackd -dalsa -dhw:XTC23773514 -R44100 -p1024 -n2 invocation to allow other sound apps to get at the capture channels.

For example, when Jack is running, and the XTC soundcard is configured, Audacity will capture the channels.

Finally...

I've got ecasound pulling the channels off of Jack.

Is there any way to configure ALSA and not have to worry about running Jack? There should be no reason ecasound can't grab capture channels from ALSA. But I almost literally have no idea what I'm doing, and concepts doc is a bit thin here.

And yep, my next effort is to go after MIDI. Already have Python sending sysex. Just need to figure out doing that and capturing multitrack simultaneously.

Thanks for the help LM!
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