I recently purchased a BOSSA OB-5, its a great bass, but I can't seem to figure out all of the knobs and trim pots. I have figured out that the toggle switch up combined with the blend knob clockwise gives me both inner single coils of the pups and just the neck pup when the toggle is down. With the blend counterclockwise and the toggle up I get both outer single coils, and the bridge pickup when toggle is down. That only took me an hour or so to figure out..lol!! Now here's the problem, I have three, yes, 3!! trim pots in the cavity. I have figured that the 2 right next to each other control the volume of the single coils, meaning when the two outer coils are working, one trim pot turns them off and vice versa. Now the 3rd trim pot is the mystery. It seems to be a mid control of some kind, but there is a mid control on the bass, at least I think its a mid knob...it seeems like low mids. When I turn the 3rd trim pot, I seem to lose some high mids, but thats all I can figure out. I thought it was a frequency pot for the mid knob, but it doesn't do anything to change the fact that the knob bosts/cuts low mids...anyone have any solid info on what these controls really do???? I definitely could be wrong about a few of these things, but these are my guesses so far.... I am also considering selling the bass because the neck is too chunky for my taste, but I would like to know about the electronics before I do so. I am getting used to it and although the neck is weird for me, I enjoy playing it. Also, it seems millions of time more versatile than my 2 knob, 1 pickup ZON, which I can only seem to coax one particular sound out of, but that ZON neck is to die for....and a solid black body/black hardware is always "in style" so to speak.