Comment 2 for bug 359361

I have managed to make the problem disappear. And reappear.

On a fresh reboot, if I go to menu->System->Preferences->Sound, set one of the "Sound Playback" drop boxes to be the ALSA digital output, and hit the "test" button, the sine wave is usually (if not always) distorted. If I run alsamixer in a terminal while a distorted sound is playing and mute and then unmute the digital output, the distortion disappears. In general, I can make the described distortion disappear using this method. For example when I run gnome-listen and the loud parts in the music are incorrectly distorting, muting/unmuting the digital output fixes it.

As long as the sound remains continuous, the distortion stays away. However, if I stop sound playback, and start it up later, the distortion sometimes reappears. In the sound preferences panel, this happens after an indeterminate number of hitting "test" followed by "okay". Distortion also reappears if I "fix" the disortion issue while playing test sounds in the sound settings dialog, then close that dialog and start something playing using gnome-listen, it is always distorted.

Also, once I use the sound prefs dialog or listen to "make" my sound distorted, sound playback through "aplay" is also distorted. If I then mute/unmute the digital output, "aplay" will then play undistorted sound. Seems like this proves that this is an ALSA problem, no?

So as of right now, loud passages of sound audibly distort, and the only way to "fix" it is to mute/unmute the digital output. Help?