Comment 50 for bug 886975

>>I've also noted it uses directly a node 0x19 (Audio Output Analog) instead of a node 0x17 (Audio Mixer), but I don't know if it's necessary and has to do with sound quality. I guess that sound going through the node 0x17 is hardware mixed and through the 0x19 is post-mixed by a software driver. As I said I don't know.

node 0x17 is the analog mixer silmilar to ac97 analog mixer

you lost the mic playback volume controls and 12 dB gain of hardware PCM playback volume

Node 0x17 [Audio Mixer] wcaps 0x20050b: Stereo Amp-In
  Control: name="PCM Playback Volume", index=0, device=0
  Control: name="PCM Playback Switch", index=0, device=0
  Control: name="Int Mic Playback Volume", index=0, device=0
  Control: name="Int Mic Playback Switch", index=0, device=0
  Control: name="Ext Mic Playback Volume", index=0, device=0
  Control: name="Ext Mic Playback Switch", index=0, device=0
  Amp-In caps: ofs=0x14, nsteps=0x2b, stepsize=0x05, mute=1
  Amp-In vals: [0x14 0x14] [0x00 0x00] [0x80 0x80] [0x80 0x80] [0x80 0x80]
  Power states: D0 D1 D2 D3
  Power: setting=D0, actual=D0
  Connection: 5
     0x19 0x14 0x12 0x11 0x15