I once had a Bambino with the coil split pot, and it began making an annoying buzzing noise. I traced it to the pot shaft being loose and rattling when the guitar was played. I put a felt washer under the knob and that stopped the buzz when the knob was depressed into the humbucker position, but it still buzzed in the single coil position. I rewired it for use without the coil split option, but returned it to original when I sold it. My Bambino Deluxe works fine with the coil split intact, in either position. I seldom use the single-coil position, but it is sometimes worth using.