What was the awk command that you tried?
As in the last thread a search isn't needed if the sndioctl variable is specified so
Code:
sndio_value=$(sndioctl output.level | awk -F'=' '{print $2}')
But using awk in this way should be functionally equivalent to the cut command in your script so you could try that instead if you prefer.
I'm not really familiar with YAD so I can't comment on that.