Boss GT6-B & ME50-B Volume Output Levels

[Bassman 100]

Can somebody clarify as to why the GT6-B with modelling switched off is perhaps three times louder than the ME50-B. I am guessing that the GT6-B has a Pre amp to drive the Model amps; however as I say the Amp Modelling is switched off, thereby only using it as an effects board. If it’s still going through a preamp – is it neutral ? Does it colour the output in any way ?
I have the same patches in other banks with amp modelling switched on which is an excellent feature if you need to use them without bending down to the pedal board.

[bassman1185]

The GT-6B has line-level outputs that have enough juice to run a poweramp. The ME-50B has instrument level outputs that are not designed to run poweramps.