MyNameIsMark Posted November 30, 2022 Share Posted November 30, 2022 Hi folks, I have a lovely Yamaha BB735 in my hands, but it has big noise problems & might have to go back. There's a bad noise floor, it's not subjective, it's bad. Touching the strings makes zero difference. Any position of pickup blend makes zero difference. Touching the bass/mid/treble knobs reduces noise, but it's still unacceptable. Switching to active increases the noise floor. Touching the pole pieces of the top split coil is awful, all others are silent. Continuity tests w/ a multimeter... metallic treble + mid + bass knobs + active/passive switch all test to the output jack. metallic volume & pickup blend do not test through to anything (can anyone compare please?) the strings test through to the screws holding the bridge in place, not to the coated bridge itself, and not to the output jack. My best guess without taking things to pieces... Bridge grounding wire problem, possibly simple to fix if I can hit the bridge screws or if the underside of the bridge is not coated. Volume+pickup blend grounding problem, maybe easy to run new wires, maybe awful if fighting the crimped Molex connectors & PCB. Split P grounding magnet coil grounding problem - if the underside of poles are exposed it could be simple if they're waxed/strapped up or if it's windings/solder joints... urgh... (does anyone know please) Thanks very much, Mark Quote Link to comment Share on other sites More sharing options...
MyNameIsMark Posted November 30, 2022 Author Share Posted November 30, 2022 (edited) "I've never even returned a jumper before" update... All pole pieces made incredible noise when touching, it's just that my fingers bridged the strings far more easily when testing the others. The upper split pickup has foam underneath, with a small strip of 'paper' backing which contacts the underside of the inner-most pole pieces (which is designed for a 4 string so the outer pole pieces directly contact the foam, but it's non-conductive foam). There was a stray piece of metal in there, but it made no difference. The rear housings of the volume & pickup blend pots test through to the output jack, the knob tops do not, and the knob tops are conductive - I'm not sure how the knobs do/should connect to the shaft & to the rear pot housing, but probably not a big deal. All surfaces of the bridge have a non-conductive coating, seems the screw holes do not & there's a small conductive white rectangular strip on the underside of the bridge behind the G & D strings that the bridge ground wire should contact. My bridge ground wire was a good 10mm away, tracing in the wrong direction. A bit of stripping & swearing & all is better. The noise floor has significantly reduced, strings now test through to the output jack, touching strings makes a small improvement. It's still noticeably noisier in any position on the active circuit, but no worse than a single coil. Edited November 30, 2022 by MyNameIsMark Quote Link to comment Share on other sites More sharing options...
MyNameIsMark Posted November 30, 2022 Author Share Posted November 30, 2022 "It can't all be bad" update... It's not! Other than the above, the feel & look & finish & quality of this is great, the neck is very comfortable & easy to play, it's smaller & lighter than I expected, the string spacing feels natural to me. Overall pretty happy with a gamble on my first 5-string 😅 2 Quote Link to comment Share on other sites More sharing options...
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