I just tested an SM58 direct into my B3 (ok, it's not a B2) with headphones to monitor.
Initially, (with the input signal obviously being at mic level and input switch on "passive") there was just enough signal strength to be able to hear the sound of my voice with "Arena Reverb" applied.
(Remember, this is with me monitoring through headphones, there might be plenty of volume when recording or plugging into a PA, I don't know.)
I played around a bit and ended up boosting the signal quite a bit with the "Booster" and "Graphic EQ" effects.
This was plenty of signal strength to be able to apply "Arena Reverb" quite effectively.
I'd need to play further with all the settings to get a better sound, but for now, FYI, you can use a B3 for vocal effects, so I can't see why the B2 wouldn't work as well, as long as you can boost that input signal somehow.
'80 Rick 4001. '84 Fender Power J Special, '05 USA Jazz, '11 USA Precision, M Miller Jazz. Peavey T-40, Zoom B3. GB ShuttleMax 12.0, GB Uber410, fEARful 212.
Last edited by OzzyGreg : 11-23-2012 at 04:51 PM.