[LAU] Fwd: Re: Raspberry Pi and real-time, low-latency audio

[Nicola]

Il 18/04/2013 19:26, Jeremy Jongepier ha scritto:
> On 04/18/2013 02:59 PM, Nicola wrote:
>> Hi, thanks for sharing.
>> The idea is simply brilliant and it works quite smoothly following the
>> wiki[1] (Thanks again Jeremy!), i've got a UA25EX[2] and a Terratec
>> Aureon dual-usb[3].
>
> Hi Nicola,
>
> You're welcome! To me the RPi is just another device running Linux.
> And if it runs Linux it can run JACK and some of my favorite software.
> I'm sometimes baffled by the immense detour people are taking just to
> get 8 note polyphony out of the RPi for instance. Or using some
> real-time effects. Or building a drum sequencer. All the stuff is
> already there! But no, apparently they prefer to reinvent the wheel.
That's great, "keep it simple" i should say...that's why i think it's
brilliant!
>> Just a couple of things i noticed:
>>
>> 1)Using the nexus7 power adaptor everything works fine, it's a 5w 2.0A.
>> 2)if you run jack with following command as the wiki suggested "jackd
>> -P70 -p16 -t2000 -dalsa -dhw:UA25 -p128 -n3 -r44100 -s" make sure to add
>> the background "&" at the end of the line, without this the sound was
>> lousy and glitchy, at least for my UA25EX.
>
> So if you don't run it in the background sound is lousy and glitchy?
> That's weird as it shouldn't make a difference? I did find that
> raising JACK's rtprio even more (I'm now using 84) decreases the
> number of glitches.
yeah, that's what happened to me and i still don't know why.
I'll try to increase the rtprio as well, good tip, thanks!
>
>> 3)Using this usb wireless adapter[4], so in a headless fashion, i had
>> many jack's disconnection no matter what frames/periods i choose.Any
>> suggestion to improve it?
>
> At the moment, no. I don't have any experience with WiFi dongles and
> the RPi. I should give it a try.
"Unbinding" the device to the controller it's not a good idea i
suppose,the PI shares both usb ports with same controller...
>> 4)I really love the tubescreamer in guitarix, it sounds GREAT!
>
> It sure does. I for one can't do without the Treble Booster though :)
>
>> 5)I've got my PI amp now saved in a separate sd card, now i'm able to
>> switch my pi from a server into an amp by just replacing the sd card,
>> how lovely it is!?
>>
>> p.s. I was thinking to install Ubuntu on my nexus7 to control Guitarix
>> (headless through ssh -X) with the touch screen!!!
>>
>
> Great idea! I've got a bricked tablet lying around too and supposedly
> it can run Ubuntu too. Keep us posted on anything that comes out of this!
Maybe there's no need to install Ubuntu.
I found out that there are 2 apps: "Connectbot" and "X server" in the
market that that may do the job with android.
Connectbot doesn't provide the "-X" option so we should set up the
DISPLAY variable accordingly with the ip-port on the X server app.
Maybe i'm just wasting my time but i will give it a try...
>
> Jeremy
>
>> [1]http://wiki.linuxaudio.org/wiki/raspberrypi
>> [2]http://www.rolandus.com/products/details/970
>> [3]http://www.amazon.co.uk/Terratec-Aureon-Dual-USB-Notebook/dp/B000WL23KC/ref=sr_1_1?ie=UTF8&qid=1366289839&sr=8-1&keywords=terratec+aureon+dual+usb
>>
>>
>> [4]http://www.edimax.co.uk/en/produce_detail.php?pd_id=328&pl1_id=1&pl2_id=44
>>
>>
>>
>> Nicola
>
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