Long time reader, first time poster. I'll start by saying I love kde, as it looks great and performs perfectly on all my modern machiens. Though I've had one issue for as long as I can remember on one computer. On a full clean install of Kubuntu 12.10 my sound card does work. Though it will stop working if I access Phonon via multimedia. Now you may ask, "what do you mean by stop working?". I this case all audio out of the sound card, I mean the physical PCI card, the line out connectors do not produce any output. Though the audigy live drive will play sound via the headphone out (I don't know about the digital, but I need the analog, though for trouble shooting I can find a way to test it if need be). Sound can not be restored till reboot. That's where I am right now, here is some loose and fast information on what I have done:

Minor Trouble shooting
-Checked alsamixer, all settings fine digital set as it should
-checked user groups, added to audio, video and pulse, there is no change
-Tried Xubuntu 12.04 and Ubuntu 12.04 no issue with sound at all
-Windows XP Pro works fine

Operating systems
-Kubuntu 10.04 does not have this issue anything greater than that does the above
-Debain Squeeze (6) does not have this issue
-Kubuntu 12.10, removed pulse audio, no change
-Installed other sound cards, no problem with audio in kubuntu 12.10
-again anything not using KDE as a desktop works fine with sound and no issues come about.

System
-Motherboard = Asus M4A785T-M (Internal sound disabled)
-Video = Built in AMD HD 4200 (HDMI Audio is disabled)
-Sound Card = SB0240 with live drive
-Capture = HVR-1255 (Issue exisited before this card was ever installed)
-Wireless card (RA-Link type? with or without it no change with issue)
-CPU = dual core athlon 3.0 ghz
-Antec 450 watt psu
-4 gig of kingston ram
-Hard Drive = 1 TB Hitachi
-DVD/RW

What I'm really looking to do at this point is solve this issue, but I need some help and pointers, and yes I've googled for literally hours and not found a good answer, so I hope to document my progress with your help to create a answer on why this issue happens if it isn't uniqe to me. This is a clean install so I'm willing to experiment and reinstall if need be. I also have a SB0350 (Audigy 2 zs, and yes it is a LITTLE different) and a SB0460 x-fi coming in (both compatible with my live drive which I want to keep). To see if this is present on other cards that are much similiar to mine. Yes I know there are better cards out today, but I'm attached to the live drive, and this family of cards has always done well for me. Overall I seem to find the problem is with phonon, as it is the only unique piece to KDE as Xubuntu and ubuntu 12.10 have no problem. Thanks for any help.

P.S. Question, what is happening when you click on multimedia and then click "phonon" if a sound is playing it will stop dead in its tracks and the issue is present till reboot. I mean what does that action do? What is exicuted? I'm looking for does it check the audio hardware someway? Initialize something? I'm grasping at straws, as to what is going on to cause this.

As Phonon itself is not involved in interacting with the hardware, but merely invokes backends (such as GStreamer, VLC, Xine, etc) to do it's bidding, it must be the backend causing this - or a related service such as Pulseaudio (old favourite, it locks the audio device, disabling DMix in the process).

Which Phonon backend is currently selected? It will likely be GStreamer or VLC.

Interesting, that makes phonon a little clearer. Right now it is gstreamer. A brand spanking new install of kubuntu 12.10. I remember trying the VLC backend before, but it may be worth anther try. I just find it odd as these backend components exist on other desktops, but don't cause the same issue. Dmix lockup? Is there something I can read that can shed some more light on that? I have removed pulse audio on kubuntu 12.10 before (not the current install, I wanted to start with a fresh install to remove any varibles from the equation) and I had the same issue.

Update...
Decided to do the following steps:
-made sure user is part of audio and video groups
-Installed VLC-backend, produced static mixed with sound, initial problem still existed
-Removed pulseaudio via muon, used the purge option. Restarted, no audio at all
-tried both gstreamer and vlc backends
-https://bbs.archlinux.org/viewtopic.php?id=123944 added the last bit about the configuration file, still no go
-deleted the phonondevicesrc from my user directory, no change
-Stopped, started craming for my physics test... wait thats not a step

Current status
-No sound at least via the phonon test button

Anything for ideas is appreciated, as having to do a fresh install on this machien is always an option (though not needed, but just easier).

Update... I decided to download and boot opensuse 12.2 ... well no issue at all with opensuse, could test audio no problem and everything works great. Anther path to investigate as to why. Also fedora 17 kde spin has no problem. This seems to be kubuntu related, so I'm going to dig around there forums. If I start a post I will link it to this one, as it may help and this seems to be a kubuntu issue not a kde one.

Update2... Recieved the x-Fi and audigy 2 zs (SB0350). With kubuntu 12.10, both cards worked perfect, except the fact that live drives arn't enabled with the x-fi in the current alsa drivers or any for that matter in linux. Though the really really really odd point is that the audigy 2 zs (SB0350) works fine and the audigy 2 (SB0240) does not. What a weird issue, well I got an upgrade for cheap out of the deal. So if your have an audigy 2 and want to keep your live drive and want to use kubuntu, the easy out is to upgrade to the audigy 2 zs. Sorry to say I don't have and probably won't bother looking further into finding the real issue with kubuntu at this point.

Marked as solved. A pity the real problem could not be found however - I suspect the problem (given the lack of Pulseaudio) was probably somewhere in the use of hardware mixing / DMix or the ALSA drivers.