when i go into alsamixer (alsamixer -c0) i can increase headphone volume up from 0 (dB gain= -59.50) up to 100% (db gain= -5.40) and it does exactly what i want.

it seems to keep the volume set at 100% level when i take out the headphone jack then back in but it resets to 0 after I reboot .... is there any way to hard save this setting???