By far one of the most inexpensive and Linux-friendly ways to get 16 Channels of I/O into a Linux Audio Workstation is to use 2 M-Audio 1010LT Audio cards. A big thanks to John Rigg http://www.jrigg.co.uk/linuxaudio/ice1712multi.html
who has made the key '.asoundrc.' configuration file available to help Linux users take advantage of multiple cards.
This guide assumes:
- A fresh AV Linux 4.2 install was used, however this guide should work for previous versions.
- The 1010LT's are being used as the only Audio devices on the system (Disable any onboard Audio chipsets in your BIOS)
- The SPDIF Channels are not mapped giving 16 A-D Converters going in and 16 D-A Converters coming out.
- SPDIF is being used for Word Clock Syncronization (A must for all 16 channels to be in Sync)
- A 44100k Sample Rate is used for the purposes of this Guide, other higher Sample Rates should be supported but are untested.
- The jackd default of 1024fpp is being used, YMMV at lower latencies.Hardware Setup: (The Easy Part)
As always disconnect the power supply cable to the PC and observe all of the regular anti-static guidelines. Place the 1010LTs side by side starting at the closest PCI slot to the Video Card slot and make sure they are completely aligned and inserted into the PCI slots.
Connect the SPDIF/Word Clock/MIDI breakout cables to both Cards. Using a digital ready RCA Cable of 3ft/1metre OR LESS connect the WHITE RCA SPDIF-Out connector from the 1010LT closest to the Video Card to the RED RCA SPDIF-In Connector on the second 1010LT.
Hardware part is done for now...Software Setup Part 1: (Don't worry not that bad)
In order to make things a little graphically simpler I've created some launchers and icons, before we get into the rest of the setup grab them here and follow the instructions:http://bandshed.net/files/M-Audio1010LTfunpack.zip
1. Download and extract the 'M-Audio1010LTfunpack' in your user's home and then open it in the file manager.
2. Hit the F4 Key on your keyboard to open a Terminal in the 'M-Audio1010LTfunpack' folder. Type 'su' into the Terminal and enter your Root password.
3. Copy the 'pcm_multi.png' icon to /usr/share/icons with this command:
cp pcm_multi.png /usr/share/icons
4. With the Root terminal still open copy the PCM Multi launcher and the Mudita24 (Card2) launcher to /usr/share/applications with this:
cp envy24_controlcard2.desktop pcm_multi.desktop /usr/share/applications
5. You can close the Root Terminal now. Right-click and copy and paste the 'asoundrc.txt' file to your user's home folder.
6. Move to your user's home, right-click on the 'asoundrc.txt' file and rename the file '.asoundrc' (The DOT(.) is important, don't use the quotes).
7. If the file disappears from view that is normal, to see it check off 'Show Hidden' in the 'View' menu of the file manager to make sure it's there.Software Setup Part 2: (We're gettin' there...)
To make sure our 1010LT's are correctly setup we need to do some checks from the Terminal and correctly route the Word Clock via SPDIF.
1. First check the presence and IRQ's of the 2 1010LT's. Open a terminal and use this command:
You should see something like this:
This is good news, the system sees 2 distinct cards on separate IRQ's (we don't want anything Audio related sharing IRQ's). If you are seeing any other Audio devices at this point you need to make sure any onboard Audio devices are disabled in your BIOS. If any other devices are present the rest of this guide will NOT work properly!
2. SPDIF Routing: Go to your Menu-->Soundcard Utilities, If you've installed the M-Audio funpack above you should see 2 entries for 'Mudita24 control' - one for Card 1 and a second 'Mudita24 control (Card2)' for the second card. For now Click on 'Mudita24 control' and the Mixer for Card 1 will open....scroll over to the 'Hardware Settings' tab and set Card 1 like this:
3. Now from the Soundcard Utilities menu click on 'Mudita24 control (Card 2)' and set Card 2 like this (notice the different IRQ's listed in the Window names):Software Test and Verify Running JACK:
1. Let's see if JACK is happy, open a Terminal and enter this. If you want a higher Sample Rate then change the '-r' value to a higher supported number. If you do change the Sample Rate make sure the matching change is also made in the Card 1 Hardware Settings above :
jackd -R -d alsa -r 44100 -C multi_capture -P multi_playback
You should see something like the following:
If you see an error message at the bottom saying 'jackd watchdog: killing jackd
' then it is most likely due to Word Clock not being set up properly with your SPDIF routing. Check your SPDIF Cable and connections again and retry. If the terminal shows no errors we can check if our 16 channels of I/O are available to the system.
2. Go to Menu-->JACK Plugins and open linuxDSP's 'JACK Patchbay' if everything is working correctly you should see a beautiful list of 16 Inputs and 16 Outputs available to use in Sequencer or any other JACK app of your choosing like this:**NOTE**
The M-Audio funpack also has supplied a quick launcher to graphically execute the jackd command above, you can find it in the 'Soundcard Utilities' menu as 'PCM_Multi Start'. This launcher will open a little xterm window to show you what JACK is doing, don't close the xterm unless you want to shut down JACK. To modify the launcher for a different Sample Rate simply edit the 'Exec=' line of the launcher file. To do this go to the 'Accessories' menu and open a Root Terminal and use this command:
This will open the gedit text editor with the launcher and you can modify the 'Exec=' line (within the quotations) as wanted and then hit 'Save' in gedit.
Comment=Start JACK with Multiple 1010LTs
Exec=xterm -e "jackd -R -d alsa -r 44100 -C multi_capture -P multi_playback"