Zoom B3 Balanced out being affected by the global control

Hey folks,

I have a Zoom B3 and I am trying to use it as a DI to the mixing desk for recording but I have to turn the Global level down so low so that I don't overdrive the mixing desk. Not normally a problem but I am miking the amp as well and the global control is lowering the output at the 1/4" jacks as well thus reducing the output of the amp. Can anyone offer any advice on how to lower the XLR output without affecting the input to the amp? Is there a pad on the B3 that can be activated and where is it!!!?