saam@bigblackbox:/tmp$ jack_control ds alsa dps device hw:PCH dps rate 48000 dps period 1024 dps nperiods 2 start
--- driver select "alsa"
--- driver param set "device" -> "hw:PCH"
--- driver param set "rate" -> "48000"
--- driver param set "period" -> "1024"
--- driver param set "nperiods" -> "2"
--- start
DBus exception: org.jackaudio.Error.Generic: Failed to open server
saam@bigblackbox:/tmp$