Comment 3 for bug 1330253

you need to ask the developer why not create front playback volume for line out Jack at rear panel when there is enough volume control for headphone, lineout and internal speaker for your business desktop

Node 0x08 [Audio Mixer] wcaps 0x20010f: Stereo Amp-In Amp-Out
  Control: name="PCM Playback Volume", index=0, device=0
    ControlAmp: chs=3, dir=Out, idx=0, ofs=0
  Amp-In caps: ofs=0x00, nsteps=0x00, stepsize=0x00, mute=1
  Amp-In vals: [0x00 0x00] [0x00 0x00]
  Amp-Out caps: ofs=0x40, nsteps=0x40, stepsize=0x03, mute=0
  Amp-Out vals: [0x40 0x40]
  Connection: 2
     0x02 0x07
Node 0x09 [Audio Mixer] wcaps 0x20010f: Stereo Amp-In Amp-Out
  Control: name="Headphone Playback Volume", index=0, device=0
    ControlAmp: chs=3, dir=Out, idx=0, ofs=0
  Amp-In caps: ofs=0x00, nsteps=0x00, stepsize=0x00, mute=1
  Amp-In vals: [0x00 0x00] [0x00 0x00]
  Amp-Out caps: ofs=0x40, nsteps=0x40, stepsize=0x03, mute=0
  Amp-Out vals: [0x40 0x40]
  Connection: 2
     0x02 0x07
Node 0x0a [Audio Mixer] wcaps 0x20010e: Mono Amp-In Amp-Out
  Control: name="Speaker Playback Volume", index=0, device=0
    ControlAmp: chs=1, dir=Out, idx=0, ofs=0
  Amp-In caps: ofs=0x00, nsteps=0x00, stepsize=0x00, mute=1
  Amp-In vals: [0x00] [0x00]
  Amp-Out caps: ofs=0x23, nsteps=0x41, stepsize=0x03, mute=0
  Amp-Out vals: [0x3d]
  Connection: 2
     0x02 0x07