I use a marshall AS50 acoustic amp as my stage amp and believe it is fantastic for reproducing the sound from the hd500. I set the HD500 to line out and then XLR into PA's where I play and use the 1/4 out s to go to the front of the AS50 or into the effects return depending on how loud I am allowed to be on stage. Being an acoustic amp it reproduces the full range really well. One thing to remember when using an amp in to the front is to set the channel bass and treble to minimum. A lot of people dont realise that the EQ controls on amps tend to be passive (i.e. when you turn the treble up you are actually reducing the bass) and setting the EQ controls to 12 o'clock changes the sound from the hd500 quite a bit. I have played with a few different bands and all are very suprised at the volume and quality of tone that comes out of the acoustic amp. it just doesn't look like those sounds should come out of it.
Hope that helps.
