+1 for TCHelicon Voicelive, I have two of their 'Touch' models, one for sax, one for vocals. These you press fit into the mike stand when setting up pre-gig below the mic itself, and everything is by backlit touch control and led indicators, so much better than stompbox groping around on the floor to change settings. I use the sax one to add double and octave down to get a good soul sax section with baritone added to tenor. I use SM57s via the TC into the main desk. I find in-ear monitoring absolutely essential to hear exactly what the Helicon is putting through the PA.