saam@bigblackbox:/tmp$ jack_control ds alsa dps hw:PCH dps rate 48000 dps period 1024 dps nperiods 2 start
--- driver select "alsa"
--- driver param set "hw:PCH" -> "dps"
DBus exception: org.jackaudio.Error.InvalidArgs: Invalid container address 'driver':'hw:PCH':'(null)' supplied to method 'GetParameterInfo'.
Unknown command 'rate'
Unknown command '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$