Wolfson Audio Card for Raspberry Pi

Just ordered a Wolfson Audio Card for Raspberry Pi via RaspberryStore. I asked them about this audio interface at their stand during the NLLGG meeting where I did a presentation about doing real-time audio with the RPi and they told me they would ship it as soon as it would become available. They kept their word so I’m hoping to mount this buddy on my RPi this very week. Hopefully it will be an improvement and allow me to achieve low latencies with a more stable RPi so that I can use it in more critical environments (think live on stage). It has a mic in so I can probably set up the RPi with the Wolfson card quite easily as a guitar pedal. Just a pot after the line output, stick it in a Hammond case, put guitarix on it and rock on.

Wolfson Audio Card for Raspberry Pi
Wolfson Audio Card for Raspberry Pi

Wolfson Audio Card for Raspberry Pi

Resolved JACK issues on notebook

Finally got around troubleshooting the issues I was facing with JACK on my notebook, a BTO that is actually a Clevo W170ER. Somehow I couldn’t go lower than -p128 with USB audio interfaces. When I thought I had tried every option, even disabling hyperthreading, I noticed two unidentified entries in my lsusb output:

Bus 001 Device 003: ID 8087:07da Intel Corp. 
Bus 002 Device 003: ID 5986:0401 Acer, Inc

The first entry is a Bluetooth adapter and the second entry is a webcam. Both devices are unnecessary when making music so I thought, why not unbind them. First I had to figure out their respective bus ID’s:

$ tree /sys/bus/usb/drivers/usb
/sys/bus/usb/drivers/usb
??? 1-1 -> ../../../../devices/pci0000:00/0000:00:1a.0/usb1/1-1
??? 1-1.3 -> ../../../../devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.3
??? 2-1 -> ../../../../devices/pci0000:00/0000:00:1d.0/usb2/2-1
??? 2-1.6 -> ../../../../devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.6
??? bind
??? uevent
??? unbind
??? usb1 -> ../../../../devices/pci0000:00/0000:00:1a.0/usb1
??? usb2 -> ../../../../devices/pci0000:00/0000:00:1d.0/usb2
??? usb3 -> ../../../../devices/pci0000:00/0000:00:14.0/usb3
??? usb4 -> ../../../../devices/pci0000:00/0000:00:14.0/usb4

Since the Bluetooth adapter sits on bus 1 and the webcam on bus two their respective ID’s should be 1-1 and 2-1. So I echoed the ID’s to the unbind file in the same directory:

$ echo -n "1-1" | sudo tee /sys/bus/usb/drivers/usb/unbind
$ echo -n "2-1" | sudo tee /sys/bus/usb/drivers/usb/unbind

Good riddance:

$ lsusb
Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub

Then I started JACK again with -p64 using an USB audio interface connected to bus 3 (so no rate matching hub in between) and no more xruns, not even with a generic kernel and using WiFi and all. Next hurdle is the onboard sound. Below -p128 I get bursts of massive xruns and so far I didn’t manage to pinpoint the culprit.

Edit #1: I’ve found out that the Bluetooth adapter is the main bottleneck. Also, by echoing the aformentioned ID’s (1-1 and 2-1) you disable the whole USB bus apparently. To disable just the USB device echo the last ID in the respective path names, so for the Bluetooth adapter that’s 1-1.3 and for the webcam 2-1.6. This way you can still use the USB bus on which these devices are residing. In my case disabling the whole bus is not an option, this would mean I’d have to connect all my USB interfaces to bus 3 (bus 4 doesn’t have any external inputs) which could result in these devices getting in each other’s way with regard to bandwidth. After echoing the ID’s the output of the tree command looks like this:

$ tree /sys/bus/usb/drivers/usb
/sys/bus/usb/drivers/usb
??? 1-1 -> ../../../../devices/pci0000:00/0000:00:1a.0/usb1/1-1
??? 2-1 -> ../../../../devices/pci0000:00/0000:00:1d.0/usb2/2-1
??? bind
??? uevent
??? unbind
??? usb1 -> ../../../../devices/pci0000:00/0000:00:1a.0/usb1
??? usb2 -> ../../../../devices/pci0000:00/0000:00:1d.0/usb2
??? usb3 -> ../../../../devices/pci0000:00/0000:00:14.0/usb3
??? usb4 -> ../../../../devices/pci0000:00/0000:00:14.0/usb4

The lsusb command still shows the devices though.

Edit #2: unbinding drivers like described above won’t persist across reboots. If you’d like to make the unbinding persistent you could add the unbind command to /etc/rc.local or create a script that runs at login. There are other options of course like blacklisting the Bluetooth drivers.

Resolved JACK issues on notebook

LAC2013: Saturday 11th of May

Somehow I managed to arrive just in time to set everything up for my workshop, like always. I’m very good at stumbling in at the very last moment. The Nvidia binary blob didn’t like a beamer attached to it so I couldn’t properly display my slides. The well-filled room didn’t seem to care, they were more interested in what I had to say and the equipment I brought with me. I talked and talked and only briefly demonstrated the Raspberry Pi I brought with me. Guess I could’ve done a whole workshop about the RPi because apparently that little device caught most of the attention.

Right after my workshop I rushed to Rui’s intercalated workshop about the software he develops. I missed his first workshop which took place on Thursday. But since Rui had so much more to show after that initial workshop the LAC2013 organization decided to allot him more time for an extra workshop. But I also didn’t want to miss Jörn’s workshop so I decided I also wanted to see part of that workshop too. Even though I’ve been using Rui’s software for years (I’m a QA, Qtractor Afficionado) he showed things I had never seen before. And I probably attended one of the best parts of Jörn’s workshop where he showed and made us listen to what he did with a live recording. An ear opener, really, amazing what you can do with a good pair of ears, years of experience and the right tools.

Then it was lunchtime already. Missed out on the warm lunch but when that was all cleared the alternative food stand was set up again which had probably even better food. They had great salads, fruit juice, bread and other tasty things, all for free. Many, many thanks to the organization for setting this up, it really added up to the overall positive vibe of the conference.

Now I had a bit of a problem. I needed to go to the Forum Stadtpark to do a sound check for the Linux Sound Night. But walking was not an option with all my stuff and public transport would take too long as there was no direct connection. Luckily I could tag along with the guys from SuperDirt² so I hopped into their car and off we went. SuperDirt² had to play last so they did their sound check first. I watched their sound check in awe, these guys were good! I was up next. Everything went smooth, monitors were good, the sound guy was a really cool guy and so was the stage manager for the event. All omens were very positive!

We got back right on time for Albert Graef’s talk on creating LV2 plugins with Faust. We witnessed a glimpse of the future. If I got it right it will be extremely easy to create your own LV2 plugins in the near future. Just throw some Faust code against it and upload it with your browser and within moments you can download your own LV2 plugin! Time to learn some Faust I guess. One lightning talk later we witnessed another glimpse of the future. No, not my acrylic guitar in the hands of Bruno Gola but the world premiere of the MOD Quadra digital pedal board. The excitement was tangible. But the MOD guys quite easily redeemed the high expectations. The MOD Quadra is simply an amazing device, the web GUI looks stunning and it’s all so easy. And it runs on Linux people, using the LV2 framework. If this doesn’t propel LV2 into mass adoption then what?

For dinner we ended up in a nice Italian restaurant. The Gösser tasted good, same for the dish I ordered (Calamari alla griglia). After dinner we walked to the Forum Stadtpark where we were welcomed by the pleasant chaos of Android drummers. I installed the app and joined the concert. It was fun. Then the beamer got switched on showing us two terminal windows with vim on the right side and something compile-ish on the left. On stage a person in front of a notebook, coding live. The result? Really cool stuff if you ask me, just watch for yourself.

Algorave to the max all y’all!

Then it was time for something remotely dance related, namely me. Really enjoyed the gig even though my voice let me down after the third song. The guy that came after me unfortunately was a bit the odd one out so the contrast with the last act, SuperDirt², couldn’t have been bigger. As soon as Käpt’n Dirt hit the strings of his cello we knew this was going to be a blast. And when Ras Tilo kicked in the party was complete. What a great show!

After the encore of SuperDirt² it was time for the Open Jack Session. Not Jack as in JACK but Jack as in 3.5″ mini-jack. It was lying there on the table on stage and after ClaudiusMaximus Marije Baalman plugged in. Live coding in SuperCollider with every once in a while Marije stretching her arms because of the anti-RSI alarms that kept popping up. Great stuff, very enjoyable to listen to and the added humorous note of the anti-RSI alarms perfectly summed up what this conference was all about: having a great time. Despite the submerging inebriation I was enthralled.

We stayed until we got kicked out. That’s how it should be. Sole minor blemish: the beer. That Murauer stuff was close to undrinkable.

LAC2013: Saturday 11th of May

LAC2013: Your submission has been accepted!

Twee mailtjes in mijn inbox vanochtend. Allebei mijn submissions voor LAC2013 zijn geaccepteerd! Dus op LAC2013 ga ik een workshop doen over je electrische gitaar gebruiken met Linux audio tools en ik ga een optreden doen op de Linux Sound Night.

Ben blij dat m’n submissions zijn geaccepteerd, heb alles al geboekt en zou zonde zijn als ik niks had kunnen doen. Die kans was er want kennelijk waren er best veel aanmeldingen.

Submission #34: Using your electric guitar with Linux


Almost 20 years of experience with playing guitar and over 10 years of Linux experience, one day that just had to come together. With the advent of guitarix, a virtual guitar amplifier for Linux, this became reality and coupled with the modularity of the Linux audio ecosystem a whole plethora of possibilities became accessible. In this workshop I will show the current possibilities for a guitarist with Linux audio in a hands-on, live setting.

Submission #35: The Infinite Repeat


A musician with over 20 years of experience and a computer with Linux. That’s what it boils down to. The result: conventional, decent song-writing, different sounding because of the choice to not walk the threaded paths and because of an autodidactic background, an outspoken personal taste and a open-minded worldview.

LAC2013: Your submission has been accepted!

Tijden veranderen

De vraag: Linux Audio 2012: Is Linux Audio moving forward?

De antwoorden:

I’d pose a different question:

Is OSX/Win Audio moving _backward_?

If OSX continues to move towards iOS, and Win continues to move towards Metro, and Thunderbolt stalls, and screens get smaller, and expansion ports get scarcer, then Linux might become the de-facto “pro” multimedia platform simply because the other choices have become too dumbed down.

Of course _most_ users will be happy with the ease and power of the tools that will be available on iOS/Metro. And _most_ users is where the money is, so Apple/Microsoft are chasing the right users. But there will be some serious users that need a powerful production system with big screens and big peripherals, and for these users, Linux might become the standard.

Ben Loftis – Harrison Consoles

… if you’re on the “inside” of Apple audio development its clear that their focus is really shifting away from “creative/professional audio” toward “consumer audio”. i’m talking about the OS infrastructure here, not the existing apps. now, traditionally, Apple has done an amazing job of creating technology that manages to serve the needs of both audiences, and they *may* manage to carry on doing that. but there are few signs from things going on in both iOS and the latest versions of OS X that this might not carry on. personally, i’d probably put my money on apple, but there is a real question what their (infrastructure) focus is going to be in a year or two.

Paul Davis – Ardour/JACK

Elders op het web ving ik naar aanleiding van dit topic een glimpje op van deze toekomst.

Prism Sound Lyra USB audio interface

Tijden veranderen

LAC2011 Linux Sound Night II

Heb even de andere acts van de Linux Sound Night gecheckt en tot mijn teleurstelling moeten constateren dat waarschijnlijk alleen Notstandskomitee, Nova deViator en ik Linux gebruikers zijn en ook niet opereren binnen het electro-akoestische genre zoals bij de andere 4 acts wel het geval is. Vorig jaar in Utrecht was dit een heet hangijzer tijdens het rond de tafel gesprek. Vooral Malte Steiner van Notstandskomitee maakt zich druk om de nadrukkelijke aanwezigheid van Apple apparatuur en de enorme hoeveelheid electro-akoestische muziek waarmee de bezoekers van de conferentie geconfronteerd werden. Hij werd hierin bijgestaan door een aantal andere belangrijke figuren in de Linux audio community (zoals Rui Nuno Capela en Fons Adriaensen) en aan het einde van het gesprek was de algehele consensus dat een Linux Audio Conferentie toegespitst zou moeten zijn op het gebruik van audio op het Linux platform. Dus niet op het gebruik van open source audio software in het algemeen. Daar zijn andere conferenties en festivals voor zoals bijv. Piksel.

Ik vrees echter dat de Apples weer alomtegenwoordig zullen zijn en dat er de nodige acts Mac OSX zullen gebruiken met open source software als CSound, PureData en SuperCollider, hét gereedschap voor electro-akoestische muziek. Want daar zul je veel van te verstouwen krijgen tijdens LAC2011. Ruw geschat denk ik dat ongeveer driekwart van alle aanwezige acts binnen dat genre actief zijn. Geen rond de tafel gesprek dit jaar maar ik zie het al gebeuren dat activistische deelnemers dan zelf wel zo’n vergadering gaan beleggen.

LAC2011 Linux Sound Night II

LAC2011 Linux Sound Night

Van de week is het programma van de Linux Sound Night die op 6 mei zal plaatsvinden gepubliceerd. Ga het podium delen met o.a. Notstandskomitee (Malte Steiner) en Nova deViator (Luka Princic). Snap niet waarom ik niet in dat plaatje zou passen. Heb al een tijdje contact met Luka, hij wil een track van mij remixen en een track van hem door mij geremixed hebben. En Notstandskomitee is lekkere jaren ’80 synthesizer muziek en als ik de reacties mag geloven op diverse fora over mijn werk dan zouden mijn nummers duidelijk beïnvloed zijn door acts uit die periode (New Order is wel de bekendste).

Komende periode heb ik lekker veel vrije dagen dus kan me goed voorbereiden. Helaas heb ik nog geen verdere informatie van de organisatie van de Linux Sound Night mogen ontvangen dus heb geen idee wat ik kan verwachten. Geen speelschema, geen informatie over de faciliteiten, helemaal niks. Ach, in die 20 jaar dat ik bezig ben heb ik er vaak genoeg zelf achteraan moeten zitten, bijna niks komt vanzelf.

LAC2011 Linux Sound Night

LAC2011 update

Het programma voor LAC2011 is klaar. Twee keer anderhalf uur mag ik van wal steken. Vrijdag 6 mei om 14.00 met Configuring your system for low-latency real-time audio processing’ en zaterdag 7 mei om 14.15 met A musician’s workflow: composing, recording and arranging with qtractor and friends’. Zaterdagavond zal ik ook een live optreden doen tijdens de Linux Sound Night.

De Linux Sound Night was een beetje een gedoe. Mijn aanmelding was om de één of andere vage reden afgewezen. Zou volgens de organisatie (een groep studenten van de NUIM) niet passen binnen het idee/thema dat ze in gedachten hadden voor de avond. Heb ze een mail gestuurd met daarin mijn bezwaren hiertegen en vervolgens is mijn aanmelding alsnog goedgekeurd:

After having thought about my submission being declined I realized a few
things:
– One of the workshops I do at LAC2011 was closely linked to a possible
performance (http://lac.linuxaudio.org/2011/raw.php?pdb_filterid=2)
– If I would’ve known about the sound you wanted to create for the night
I could have anticipated and made sure my submission would fit the event
– There are very few people making music with Linux professionally and
even fewer using Linux live on stage so I wondered who actually
submitted and in how far those acts do sit with the sound you have in mind
– It’s a Linux Sound Night so the event already has a theme, restricting
it even further to a subjective musical taste shouldn’t be taken into
consideration imho. It’s like organizing a vintage Japanese car show but
only allowing red and blue cars because those are the favorite colors of
the organization board (sorry for the car analogy).

Nadat dat allemaal geregeld was ben ik aan de voorbereidingen begonnen. Heb een FireWire ExpressCard moeten aanschaffen voor mijn notebook aangezien de onboard JMicron controller weigerde samen te werken met mijn Focusrite FireWire geluidskaart. Dat werkt inmiddels naar behoren zodat ik thuis mijn live set-up goed kan testen en mijn setje en workshops kan voorbereiden.

LAC2011 update