Martin Fishmnan stereo prefix

[rockdawg]

I have a Martin Fishman stereo prefix preamp in my Martin MC16 GTE. The high B and E strings are noticeably louder than the other strings when using the internal pickup alone. I took it to a pro repair person and he said it was in the guitar crooked and he fixed it and it now sounds better. but the problem is still there. Has anyone had this problem? How did you solve it?

[Joe Barbieri]

It is virtually impossible for an Acoustic Matrix pickup (which is the UST used in the Prefix systems) to be more responsive in some areas and less responsive in others due to a defect in the pickup. The reason for unbalanced string volumes, in most cases, is a lack of down-bearing pressure on the pickup under the weaker strings. This translates to lower volume for that particular string. This problem can be caused by many things including an uneven saddle slot, a saddle with an uneven bottom surface, a guitar that is "belly-up", a lifting or loose bridge, poor fit of the pickup in the saddle slot or an insufficient break angle of the strings over the saddle. It is also critical to have what we refer to as a 50-50 saddle fit, so that 50 percent of the saddle is inside the slot and the other 50 percent is over the top of the bridge. A saddle that is too deep or too shallow can give you balance issues. A qualified repair shop should be able to identify which issue, or issues, you are dealing with and make the appropriate corrections. Since it's the E and B strings, I'm guessing the bottom of the saddle is not flat or the saddle is binding slightly at the treble end of the slot. It may just need a little sanding. Good luck.