Regarding the noise,
I suspect there's some impedance mismatching.
What kind of
signal are you feeding the unit, line level +4dB or instrument level
-10/-20dB? From which sound source? How the unit is wired?
You can store Usergroups. Press The PROGRAM KEY for a few seconds several times until you read Usergroups on the top left line. That's where you can execute such operation.
best
I
