I bought the Clearsonic A3-2 Shield for taming the volume of my JTM-45 (which does not have a master volume) on stage. It does this job very well, and got me lots of praise from the sound engineers especially at smaller locations. It works especially well when you are set up close to your amp. The further you have to be way from it, the more you will have to rely on good monitoring, because the shield blocks out sound so well - which would be the only downside to using it. The good news are that your singer and everyone in first row will love you for doing so!