amazing! hope it works *** see note below ***
"Low Sound Volume
If you are facing low sound even after maxing out your speakers/headphones, you can give the softvol plugin a try. Add the following to /etc/asound.conf.
Note: You will probably have to restart the computer, as restarting the alsa daemon did not load the new configuration for me. Also, if the configuration does not work even after restarting, try changing plug with hw in the above configuration.
After the changes are loaded successfully, you will see a Pre-Amp section in alsamixer. You can adjust the levels there.
Setting a high value for Pre-Amp can cause sound distortion, so adjust it according to the level that suits you.
Some audio codecs may need to have settings adjusted in the HDA Analyzer (see #Volume is too low) in order to achieve proper volume without distortion. Checking the HP option under widget control in the Playback Switch (Node[0x14] PIN in the ALC892 codec, for instance) can sometimes improve audio quality and volume significantly."
linked from Wognath at http://www.murga-linux.com/puppy/viewtopic.php?p=931775&sid=7123dad5d4104b5a4baaf4fe303654c8#931775
*** perhaps better to copy the code from the original as sometimes this forums software messes code up.
read Wognath's comment too