I have a DA3 and you have full control on every channel, including increasing or attenuating each channel. I think by either +/-10db max or +/-12db in 1db steps.
Don, I Too, Have the DA3ES but it only allows for the following in the level menu:
Front-- balance surround--balance center--level -10 to +10 surround--level -10 to +10 surround back--level -10 to +10 sub level--off,-20 to +10 LFE mix level--off,-20 to 0 dynamic range compression level
Gerard, I set my mains with the master volume, and every thing else to match them.
My 4ES has balance for the front left/right and +/- controls for all other channels. This means you use the balance to even out the front L/R and use the +/- to match the center, surrounds, and back surrounds.