# Mic problems with ALSA and nVidia MCP55 HDA

## JimmyJoeBob

Hello,

I am in the process of moving over to Gentoo from Ubuntu, and I seem to have everything I need working except my microphone.  As the title says, my card shows up as "nVidia Corporation MCP55 High Definition Audio (rev a2)".  Playback works fine, but my I can't get any input from my mic.  Instead, I get loud static, or, if I remove and the reinstall the snd-hda-intel module, nothing.  Any ideas?  I have tried pretty much everything in alsamixer (turn up PCM/master/mic, turn on capture, turn up mic boost, etc.) and gnome-volume-control.  I have also tried configuring some things in alsa.conf, no luck so far.

Info:

```
SKYWALKER / # lspci

00:00.0 Host bridge: nVidia Corporation C55 Host Bridge (rev a2)

00:00.1 RAM memory: nVidia Corporation C55 Memory Controller (rev a1)

00:00.2 RAM memory: nVidia Corporation C55 Memory Controller (rev a1)

00:00.3 RAM memory: nVidia Corporation C55 Memory Controller (rev a1)

00:00.4 RAM memory: nVidia Corporation C55 Memory Controller (rev a1)

00:00.5 RAM memory: nVidia Corporation C55 Memory Controller (rev a2)

00:00.6 RAM memory: nVidia Corporation C55 Memory Controller (rev a1)

00:00.7 RAM memory: nVidia Corporation C55 Memory Controller (rev a1)

00:01.0 RAM memory: nVidia Corporation C55 Memory Controller (rev a1)

00:01.1 RAM memory: nVidia Corporation C55 Memory Controller (rev a1)

00:01.2 RAM memory: nVidia Corporation C55 Memory Controller (rev a1)

00:01.3 RAM memory: nVidia Corporation C55 Memory Controller (rev a1)

00:01.4 RAM memory: nVidia Corporation C55 Memory Controller (rev a1)

00:01.5 RAM memory: nVidia Corporation C55 Memory Controller (rev a1)

00:01.6 RAM memory: nVidia Corporation C55 Memory Controller (rev a1)

00:02.0 RAM memory: nVidia Corporation C55 Memory Controller (rev a1)

00:02.1 RAM memory: nVidia Corporation C55 Memory Controller (rev a1)

00:02.2 RAM memory: nVidia Corporation C55 Memory Controller (rev a1)

00:03.0 PCI bridge: nVidia Corporation C55 PCI Express bridge (rev a1)

00:06.0 PCI bridge: nVidia Corporation C55 PCI Express bridge (rev a1)

00:07.0 PCI bridge: nVidia Corporation C55 PCI Express bridge (rev a1)

00:09.0 RAM memory: nVidia Corporation MCP55 Memory Controller (rev a1)

00:0a.0 ISA bridge: nVidia Corporation MCP55 LPC Bridge (rev a2)

00:0a.1 SMBus: nVidia Corporation MCP55 SMBus (rev a2)

00:0b.0 USB Controller: nVidia Corporation MCP55 USB Controller (rev a1)

00:0b.1 USB Controller: nVidia Corporation MCP55 USB Controller (rev a2)

00:0d.0 IDE interface: nVidia Corporation MCP55 IDE (rev a1)

00:0e.0 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a2)

00:0e.1 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a2)

00:0e.2 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a2)

00:0f.0 PCI bridge: nVidia Corporation MCP55 PCI bridge (rev a2)

00:0f.1 Audio device: nVidia Corporation MCP55 High Definition Audio (rev a2)

00:11.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a2)

00:12.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a2)

00:13.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a2)

00:14.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a2)

00:15.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a2)

00:16.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a2)

00:17.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a2)

00:18.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a2)

01:00.0 VGA compatible controller: nVidia Corporation G73 [GeForce 7600 GS] (rev a1)

04:06.0 Multimedia video controller: Conexant Systems, Inc. CX23418 Single-Chip MPEG-2 Encoder with Integrated Analog Video/Broadcast Audio Decoder

04:0b.0 FireWire (IEEE 1394): VIA Technologies, Inc. VT6306 Fire II IEEE 1394 OHCI Link Layer Controller (rev c0)
```

```
SKYWALKER / # lsmod

Module                  Size  Used by

ipv6                  225928  14 

snd_hda_intel          18980  0 

snd_seq_oss            22016  0 

snd_seq_midi_event      4088  1 snd_seq_oss

snd_seq                39360  4 snd_seq_oss,snd_seq_midi_event

snd_seq_device          4012  2 snd_seq_oss,snd_seq

snd_pcm_oss            31712  0 

snd_mixer_oss          12856  1 snd_pcm_oss

nvidia               9534416  28 

snd_hda_codec_analog    74584  1 

snd_hda_codec          52096  2 snd_hda_intel,snd_hda_codec_analog

snd_pcm                55136  3 snd_hda_intel,snd_pcm_oss,snd_hda_codec

snd_timer              15880  2 snd_seq,snd_pcm

ohci_hcd               19060  0 

snd                    45480  10 snd_hda_intel,snd_seq_oss,snd_seq,snd_seq_device,snd_pcm_oss,snd_mixer_oss,snd_hda_codec_analog,snd_hda_codec,snd_pcm,snd_timer

ehci_hcd               34200  0 

snd_page_alloc          5640  2 snd_hda_intel,snd_pcm

floppy                 51304  0 

rtc                     4736  0 
```

On a side note, Gentoo is awesome!  It's so much faster that Ubuntu.

----------

## DONAHUE

you have: 

```
emerge alsa-utils

rc-update add alsasound default
```

```
alsamixer -V all
```

 http://s1221.photobucket.com/albums/dd474/donahue95/alsamixer/?action=view&current=Screenshot.png is a shot of my alsamixer setup for the same card you have that gives me a working microphone

my kernel config has 

```
<M>   Intel HD Audio  --->

 --- Intel HD Audio                                                    

-*-   Build hwdep interface for HD-audio driver                       

-*-     Allow dynamic codec reconfiguration (EXPERIMENTAL)            

[*]   Support digital beep via input layer                            

(1)     Digital beep registration mode (0=off, 1=on, 2=mute sw on/off)

[*]   Support jack plugging notification via input layer              

[*]   Support initialization patch loading for HD-audio               

[*]   Build Realtek HD-audio codec support                            

[*]   Build Analog Device HD-audio codec support                      

[*]   Build IDT/Sigmatel HD-audio codec support                       

[*]   Build VIA HD-audio codec support                                

[*]   Build HDMI/DisplayPort HD-audio codec support                   

[*]   Build Cirrus Logic codec support                                

[*]   Build Conexant HD-audio codec support                           

[*]   Build Creative CA0110-IBG codec support                         

[*]   Build C-Media HD-audio codec support                            

[*]   Build Silicon Labs 3054 HD-modem codec support                  

[*]   Enable generic HD-audio codec parser                            

[ ]   Aggressive power-saving on HD-audio
```

----------

## JimmyJoeBob

Hmm that didn't help; I'm still getting the same symptoms.  Interestingly, my alsamixer only shows "Front Mic" and "Rear Mic"; it doesn't have an option for just "Mic" as it did in Ubuntu.  Here's my alsa.conf file in case it helps:

```
SKYWALKER / # cat /etc/modprobe.d/alsa.conf 

# Alsa kernel modules' configuration file.

# ALSA portion

alias char-major-116 snd

# OSS/Free portion

alias char-major-14 soundcore

##

## IMPORTANT:

## You need to customise this section for your specific sound card(s)

## and then run `update-modules' command.

## Read alsa-driver's INSTALL file in /usr/share/doc for more info.

##  ALSA portion

alias snd-card-0 snd-hda-intel

##  OSS/Free portion

alias sound-slot-0 snd-card-0

##  OSS/Free portion - nVidia card

alias sound-service-0-0 snd-mixer-oss

alias sound-service-0-1 snd-seq-oss

alias sound-service-0-3 snd-pcm-oss

alias sound-service-0-8 snd-ssq-oss

alias sound-service-0-12 snd-pcm-oss

alias /dev/mixer snd-mixer-oss

alias /dev/dsp snd-pcm-oss

alias /dev/midi snd-seq-oss

# Set this to the correct number of cards.

options snd cards_limit=1
```

----------

## DONAHUE

were I you I would attempt to make my 

```
alsamixer -V all
```

 look just like http://s1221.photobucket.com/albums/dd474/donahue95/alsamixer/?action=view&current=Screenshot.png

----------

## JimmyJoeBob

Here is my 

```
alsamixer -V all
```

 {image removed; sorry!}

I did my best to make it look as close as I could to the image above, but as you can see, some of the options are different.  I still have no mic input with these settings (I tried several different mics).  Instead, it's just showing "Rear Mic" instead of "Mic".Last edited by JimmyJoeBob on Wed Jun 29, 2011 5:53 pm; edited 1 time in total

----------

## DONAHUE

same card different controls, somewhat surprised 

at present the only controls affecting my microphone are mic, presumably same as your rear mi, and analog mix,  presumably same as your analog m. memory says I have had to toggle captures on and raise their volumes and toggle through input sources to recover microphone in the past, but not tonight.  You probably have done so but I would raise volume on the two extra front mi and rear mi.

----------

## JimmyJoeBob

So I finally managed to solve this.  Here's what you need to do:

1.) Edit the alsa.conf file

```
# nano /etc/modprobe.d/alsa.conf
```

2.) Set up the model of the card so that it is properly recognized

```
options snd-hda-intel model=6stack
```

3.) Reboot.  I had tried this before, but it won't work unless you reboot.

4.) "Mic" should now appear in alsamixer instead of "Rear Mic"; just raise the volume, make sure capture is on, and it should work.

Also, I had originally tried using "6-jack" as suggested by the sound card information page linked to by the Gentoo ALSA guide, but that didn't work.  Hopefully this can help out some other people who are having trouble.

----------

