I'm running Puredata version 0.40-2 on Xubuntu linux with an onboard laptop cheap soundcard (realtek Ac'97), puredata uses the default Oss driver.
Was trying some of the example patches to learn more about it, and noticed that the audio coming out is just "downsampled".
This really stands up when you run patches with just sine waveforms, because you can hear all the downsampling artifacts clearly.
Looked at the Oss driver settings... it is set to 44.100 Hz as samplerate (!) so this shouldn't happen.
When I change the samplerate to (at least) 96.000 Hz (which is a really high value!) the problem disappears.
Can you explain what's going on, since I have encountered this exact problem in other audio applications (e.g. Alsamodularsynth) and not in other ones (audacity sound editor for istance).
??

i'd say it's your soundcard/driver settings that are downsampling. pd @ 44100 hz will be as clear as CD, or maybe even more so because it's 32 bit, not 16.

yes, that's what I think.
BTW, if someone ever encountered this problem using ubuntu and pd, please let me know.

One thing I have noticed with my onboard sound [1]:

If two applications try to use the soundcard at the same time with different sample rates, I get horrible distortion that sounds a bit like downsampling. eg, if I have Pd at 44100Hz and play a 48000Hz file with mplayer, it sounds very very bad.

Solution: kill all other applications using the sound card (eg: arts, esd, pulseaudio or other system sound servers) at least when using music apps. Or get a better sound card (I'm pretty happy with my Edirol UA-25 although it has some quirks).

[1] 00:1f.5 Multimedia audio controller: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) AC'97 Audio Controller (rev 03)

@ClaudMax:

Have you managed to get the midi and audio working at the same time on your edirol? I have a UA-20 and I can't figure out a midi option.

Do you get the same problem if you try to switch to alsa?

@nestor said:

@ClaudMax:

Have you managed to get the midi and audio working at the same time on your edirol? I have a UA-20 and I can't figure out a midi option.

I don't know the UA-20, but on the UA-25 it requires turning on the "advance" switch, as explained here:

http://alsa.opensrc.org/index.php/Edirol_UA-25#Advance_button

About the UA-20, Google seems to throw up this in various places:

ALSA changelog v1.0.11 - Summary: usb-audio: fix Edirol UA-20 support

But that was 2 years ago, and for audio not MIDI... hopefully your ALSA is newer? Maybe try an ALSA mailing list for help?

@ClaudiusMaximus said:

@nestor said:

@ClaudMax:

Have you managed to get the midi and audio working at the same time on your edirol? I have a UA-20 and I can't figure out a midi option.

I don't know the UA-20, but on the UA-25 it requires turning on the "advance" switch, as explained here:

http://alsa.opensrc.org/index.php/Edirol_UA-25#Advance_button

About the UA-20, Google seems to throw up this in various places:

ALSA changelog v1.0.11 - Summary: usb-audio: fix Edirol UA-20 support

But that was 2 years ago, and for audio not MIDI... hopefully your ALSA is newer? Maybe try an ALSA mailing list for help?

Sorry to hijack the thread but; are you using snd-usb-audio and usb-midi?

hey i had this problem. fixed it in the end with qjackctl settings:

frames/period: 64
periods/buffer: 2

meess with those settings a bit