I have a boss mr-8 and im whenever i mic my piano it always comes out...uh....ewww sounding. It's all grumbly and stuff. Then I noticed that when I put my mic in the xlr input thing it doesnt work. It's the onboard mic thats recording it( the onboard mic is really sesative and just not good.) How do I get my mic to work and turn the onboard one off, and don't say read the manual, trust me I have. Also, will this improve my pianos recorded sound or is it something else? My piano sounds great and i like it, but when i record it its just..uh..not clean sounding.