When I bring up alsamixer there is no master option so I cannot unmute the master channel. I think this is the reason why
I cannot hear sound.
Mplayer seems to play a file with alsa but no sound is coming out of the card.

Alsamixer starts with headphone as the first oprion (no master):
Headphone,PCM,Front,surround,center .....

Alsamixer header looks like:
 Card: HDA NVidia                                                                                                    
 Chip: Analog Devices AD1986A                                                                                        
 View: [Playback] Capture  All
 Item: Headphone                                                                                                     
                           

alsa versions:
media-sound/alsa-headers-1.0.11  
media-sound/alsa-driver-1.0.11  
media-sound/alsa-utils-1.0.11  

complied with ALSA_CARDS="hda-intel"

>>> Compiling source in /var/tmp/portage/alsa-driver-1.0.11/work/alsa-driver-1.0.11 ...
./configure --prefix=/usr --host=x86_64-pc-linux-gnu --mandir=/usr/share/man --infodir=/usr/share/info --datadir=/usr/share --sysconfdir=/etc --localstatedir=/var/lib --without-oss --without-debug --with-kernel=/usr/src/linux --with-build=/usr/src/linux --with-isapnp=yes --with-sequencer=yes --with-cards=hda-intel --libdir=/usr/lib64 --build=x86_64-pc-linux-gnu



HW:
MBO:     ASUS A8N-VM
CPU     AMB 3800+ dual core

orca ~ # lspci|grep Audio
00:10.1 Audio device: nVidia Corporation MCP51 High Definition Audio (rev a2)
orca ~ #


SW:

# alsaconf
I select hda-intel nVidia MCP51 High Def Audio rev a2
alsaconf completes with no error
# modules-update

# lsmod|grep snd
snd_seq                61760  0
snd_seq_device         10576  1 snd_seq
snd_hda_intel          20700  0
snd_hda_codec         175112  1 snd_hda_intel
snd_pcm                99272  2 snd_hda_intel,snd_hda_codec
snd_timer              27080  2 snd_seq,snd_pcm
snd                    59920  6 snd_seq,snd_seq_device,snd_hda_intel,snd_hda_codec,snd_pcm,snd_timer
snd_page_alloc         12496  2 snd_hda_intel,snd_pcm

# cat /etc/modules.d/alsa
(without commented out lines)
alias /dev/mixer snd-mixer-oss
alias /dev/dsp snd-pcm-oss
alias /dev/midi snd-seq-oss
alias snd-card-0 snd-hda-intel
alias sound-slot-0 snd-hda-intel


gcc:
orca log # eselect compiler show
x86_64-pc-linux-gnu-3.4.4/amd64-vanilla


Kernel:
Linux orca 2.6.15-gentoo-r8 #1 SMP Tue Jul 25 10:42:42 PDT 2006 x86_64 AMD Athlon(tm)64 X2 Dual Core Processor  3800+ AuthenticAMD GNU/Linux

Thanks for your help,
James