#84 rhythmic glitching on PowerBook G4

puredata (322)

On an Apple PowerBook G4 1.67GHz running 10.4.7, the
sound always had a pulsing glitch on it no matter if
any sound was being generated or not. When I switched
the output sampling rate to 48000, the glitching went
away. When I switched back to 44100, the glitching
came back.

I saw this one other time on a PowerBook, but it was
also happening to Audacity. This time it was only
happening for Pd. My guess is that its related to

This was on a student's laptop, so I can't test again.


  • Hans-Christoph Steiner

    • milestone: 594773 --> v0.40.0
  • IOhannes m zmölnig

    Logged In: YES

    experienced something similar on a G4 iBook (of a student,
    so don't ask for details...) with an RME fireface.

    this only happened with pd-extended (if i only knew the
    version...0.38, 0.39??), running vanilla pd-0.39-2 did solve
    the problem.

    the test was the "test audio and midi" sinewaves.

  • Fred Inklaar

    Fred Inklaar - 2006-11-28

    Logged In: YES
    Originator: NO

    This bug is present in all versions I tested above Pd version 0.38.4-extended-RC8.

    The highest version I tested was Pd version 0.40-2 on:
    Computernaam: PowerBook G4 15"
    Computermodel: PowerBook5,8
    Processortype: PowerPC G4 (1.5)
    Aantal processors: 1
    Processorsnelheid: 1.67 GHz
    L2-cache (per processor): 512 KB
    Geheugen: 1 GB
    Bussnelheid: 167 MHz
    Opstart-ROM-versie: 4.9.6f0

    With the following audio card specs:

    Ingebouwde geluidskaart:
    Crystal Semiconductor CS84xx:
    Ingangen en uitgangen:
    Digitale S/PDIF-invoer:
    Hoorbaar: Ja
    Plugincode: Topaz
    Burr Brown PCM3052:
    Ingangen en uitgangen:
    Interne microfoon:
    Regelaars: Geluid uit, Master
    Hoorbaar: Nee
    Plugincode: Onyx
    Regelaars: Geluid uit, Master
    Hoorbaar: Nee
    Plugincode: Onyx
    Digitale S/PDIF-uitvoer:
    Regelaars: Geluid uit
    Plugincode: Onyx
    Interne luidsprekers:
    Regelaars: Geluid uit, Links, Rechts
    Plugincode: Onyx
    Regelaars: Geluid uit, Links, Rechts
    Plugincode: Onyx

    The pulsing glitch is present when the audio card is set to the following frequencies (by using the Audio/Midi-configuratie Utility), all on 16-bit:

    44100 Hz
    88200 Hz (faster pulse)
    96000 Hz (even faster pulse)

    The glitch is not present when the audio card is set to:
    32000 Hz
    48000 Hz
    64000 Hz

  • Fred Inklaar

    Fred Inklaar - 2006-11-28

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    Originator: NO

    OK, because of zmoelnig's comment I also tested vanilla pd-0.39-2 on my PowerBook. Unfortunately, that did *not* solve the problem, the pulsing glitch is there anyway,

    But the problem is also slightly different than Hans-Christoph's description: I *do* need to generate a sound to hear the glitching pulse. Doesn't matter what sound, sinus or noise. The output sound gets dropped and restored very frequently, on a regular interval. That is what causes the pulsating glitch. So, without output no restore, thus no pulse.

  • Hans-Christoph Steiner

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    Originator: YES

    I saw this on another PowerBook G4 1.67GHz. That seems to be the only model affected. Setting to 48000 fixed it also.

  • Nobody/Anonymous

    Logged In: NO

    I don't know if this belongs here:

    mac os 10.4.8
    1.25 GHz PowerPC G4

    All my fft-based patches are not working anymore with Pd-0.39.3-extended-rc5-macosx104-powerpc.
    As described by Ed Richardson on his Powebook G4, 1.67GHz (10.4.7) "there is a fairly loud single pop, upon which all audio ceases on the computer altogether. Audio will only resume once I quit Pd."

  • cursorx

    cursorx - 2009-07-08

    This worked for my PowerBook G4 1.67 GHZ, OSX 10.4.11. Changing the sample rate of the computer from 44100 to 48000 fixed the glitching on pd 41.4-extended.

  • Hans-Christoph Steiner

    is this still an issue anywhere?

  • Hans-Christoph Steiner

    • status: open --> pending-out-of-date


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