audio hardware solution for notebook (IBM T23) for small tasks in ardour

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nikgid
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Hi folks,

I need help in finding a good audio-interface for my somewhat older notebook (Thinkpad T23 => PIII 1,3Ghz, 512mb).

What I would love to be able to do with ardour is:
- play back at least one track (the more the better)
and at the same time
- record at least one track via microphone (Sony ECM MS907)
... with really low latency.

Is this possible on above mentioned notebook?
What audio hardware would you recommend for this (USB, Firewire, PCMCIA)?
Would the Edirol UA-5 or UA-25 or Tascam US-122 suit my needs for example or is their USB 1.1 too slow for this task? (I have USB 2.0 (via pcmcia) but the Edirols are USB 1.1)
What other audio interfaces have been tested to really work reliably?
I would really like not to have to pay too much money... 200$ max ... 300$ ultra max if it is really needed.

I know of the compatibility-lists on alsa and freebob - but I would love to read from people who have actually used certain hardware with ardour for similar tasks.

Thanks,
Niklas

droebbel
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USB ist said to be rather bad for lowlatency. But in fact, with some systems (e.g. with an IBM X20 in my case) and a lowlatency-kernel (Ubuntus -lowlatency, which isn't even realtime) I was able to achieve 5,2 ms; at 2,6 ms xruns started to occur. I did not do any real long-time testing with high system load, but I might try if you are interested. I use a UA-5, so even USB 1.1 *can* work.

nikgid
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@droebbel:
Thanks for answering!

Your setup seems quite similar to what I would be able to get (x20 ~ similar generation as t23?!). Edirol UA-5 are still frequently on the 2nd-hand market.
I also use Ubuntu (fluxbuntu in my case) with a kernel from the ubuntumusique team.

So low latency seems to be quite possible... but:
Have you done recording in ardour via microphone while at the same time listening to another track with repeatedly good results? (is this called duplex recording?! recording-wise I am quite a newbie...)
Is this normal and reliably possible with the UA-5/ardour-combination? (under preconditions as a rt-kernel etc.) 16bit/44.1khz would be enough for my purposes... I just want to experiment with song-ideas for the recordings from my bands jam-sessions.

Niklas

droebbel
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No, I have never done that, as I only make recordings of classical music.
But I am going to try it, just hold on...

...EDIT:
Now this is amazing.

I started jack with
jackd -R -v -p 80 -d alsa -d hw:1 -p 128
which gives 2,7 ms / direction or 5,3 ms in/out.
I started ardour-2.0.2 with a new session, two stereo tracks. Imported some audio into the first one. Connected the second one to in1+2, enabled recording and started it. 24/48 to test maximum possible with usb1.1.

Then I opened a terminal and ran three processes in parallel:
sudo updatedb
md5sum /dev/urandom
sudo dd if=/dev/hda of=/dev/null

Is this enough for a stress test?

I could not hear any glitches neither in the playback of the previously recorded material nor in the new recording.
At the jack console I saw spare time was always over 1800 usecs.

This is on Ubuntu feisty with linux-image-2.6.10-15-lowlatency, ardour-2.0.2 (my own build based on the gutsy source package), IBM X20 with P3-M 600 and 192 MB, XFCE, jack without GUI to save RAM.

Hope that helps.
David

nikgid
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Thanks for your help David!

I will try to get me a used Edirol UA-5 or UA-25 then...

Just for the record:
I have been succesfully using even a friends Soundblaster MP3+ for "duplex recording" with jack and ardour (playing back a few tracks and recording a new instrument-track via microphone simultaneously). Even this has been working totally stable (the SB MP3+ being a cheapo usb-soundcard). The spdif on the mp3+ still seems to make problems under my current settings, but that is definitely not ardours fault...
Mic and Line in work just fine.

This is on fluxbuntu edgy with 2.6.17.6-rt7-ubuntumusique, jack started with "sudo jackd -v -R -d alsa -r 48000 -d hw:1" and ardour (v0.99.2) started with "sudo /usr/bin/ardour" on a IBM T23 with P3 1,2Ghz and 512mb.

Niklas

droebbel
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I do not run ardour and jack as root. Do you really have to?

nikgid
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I did have to run ardour and jackd with sudo to get the realtime privileges. Didn't seem to work otherwise... even with modifying /etc/security/limits.conf etc.

But that is a thing of the past... because now I run Ubuntu Feisty Fawn with the Kernel from
Ubuntustudio (2.6.20-16-lowlatency). And that lets me start jackd -R ... as a normal user - yeah!
Even seems to help with the load=... of jackd!

So... thanks again: this time for asking. I only tried it out again after reading your question. :-)