This is with: james@audio:~$ uname -a Linux audio 4.2.0-22-lowlatency #27-Ubuntu SMP PREEMPT Fri Dec 18 00:06:48 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux This was Ubuntu Studio 15.10, with pulse removed and KXStudio packages added. I have an AMD APU, and its connected to a HDMI processor (actually an Audiolab 8200AP). james@audio:~$ lspci | grep -i audio 00:01.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] BeaverCreek HDMI Audio [Radeon HD 6500D and 6400G-6600G series] 00:14.2 Audio device: Advanced Micro Devices, Inc. [AMD] FCH Azalia Controller (rev 01) 05:04.0 Multimedia audio controller: C-Media Electronics Inc CMI8788 [Oxygen HD Audio] So, we have the audio device. But ALSA does not seem to see it. alsamixer shows: Card: HD-Audio Generic F1: Help │ │ Chip: ATI R6xx HDMI F2: System information │ │ View: F3:[Playback] F4: Capture F5: All F6: Select sound card │ │ Item: S/PDIF ie just a runt SPDIF, no PCMs. I think I've turned radeon audio on appropriately: james@audio:/etc/modprobe.d$ pwd /etc/modprobe.d james@audio:/etc/modprobe.d$ cat radeon.conf options radeon audio=1 In dmesg I see this: [ 16.142396] snd_hda_codec_hdmi hdaudioC1D0: HDMI ATI/AMD: no speaker allocation for ELD [ 16.442623] snd_hda_codec_hdmi hdaudioC1D0: HDMI ATI/AMD: no speaker allocation for ELD [ 16.742857] snd_hda_codec_hdmi hdaudioC1D0: HDMI ATI/AMD: no speaker allocation for ELD [ 17.043068] snd_hda_codec_hdmi hdaudioC1D0: HDMI ATI/AMD: no speaker allocation for ELD [ 17.343309] snd_hda_codec_hdmi hdaudioC1D0: HDMI ATI/AMD: no speaker allocation for ELD [ 17.643529] snd_hda_codec_hdmi hdaudioC1D0: HDMI ATI/AMD: no speaker allocation for ELD [ 17.943756] snd_hda_codec_hdmi hdaudioC1D0: HDMI ATI/AMD: no speaker allocation for ELD [ 18.243984] snd_hda_codec_hdmi hdaudioC1D0: HDMI ATI/AMD: no speaker allocation for ELD I have rebooted, and restarted the Audiolab since I plugged in the HDMI cable. And the ELD info seems sane: james@audio:/proc$ cat ./asound/card1/eld#0.0 monitor_present 1 eld_valid 1 monitor_name connection_type HDMI eld_version [0x2] CEA-861D or below edid_version [0x0] no CEA EDID Timing Extension block present manufacture_id 0x0 product_id 0x0 port_id 0x0 support_hdcp 0 support_ai 0 audio_sync_delay 0 speakers [0x4f] FL/FR LFE FC RL/RR RLC/RRC sad_count 1 sad0_coding_type [0x1] LPCM sad0_channels 8 sad0_rates [0x6e0] 32000 44100 48000 88200 96000 sad0_bits [0xe0000] 16 20 24 james@audio:/proc$ Any idea how to tell what's going on - ? The slight weirdness is that the system is connected to the Audiolab over HDMI, but I don't have an HDMI monitor - and in fact I access the system via putty or XRDP.