Thunderpaws Posted October 5, 2019 Share Posted October 5, 2019 Hi everyone. At rehearsal this week and playing through the room’s Hartke amp. Both pickups on full and lovely full sound with no unwanted noise. THEN...rolled off one of the pups a tad to alter the sound a bit and my bass replied by making quite a bit of hum. Turned both full on again and him went. Turned the other pickup down a bit and hum reappeared. So, both pups full on = no hum Either pup down a bit = hum Anyone have a clue what’s up? It hasn’t done this before. It’s a MIJ Geddy. Ta. 1 Quote Link to comment Share on other sites More sharing options...
dannybuoy Posted October 5, 2019 Share Posted October 5, 2019 Standard feature of a Jazz bass! If you've not noticed it before, it'll be the room you were in, studios and venues often have a lot more electromagnetic interference floating about then a typical home. You can get noiseless pickups which are usually split humbuckers like a mini Precision pickup crammed into a Jazz casing, but they sacrifice a bit of top end bite. Shielding the bass including the pickup cavities could help too. 4 Quote Link to comment Share on other sites More sharing options...
NickA Posted October 5, 2019 Share Posted October 5, 2019 Conductive paint inside the pickup cavities might help a bit (connected to the ground wire if you can). A low amp impedance will reduce the noise too, but rob you of high end. A single single-coil pickup into a high impedance buffer in an electrically noisy room is the worst case. The solution is this: https://www.delano.de/jmvc_4_fe_m2/jmvc_4_fe_m2_details.html Quote Link to comment Share on other sites More sharing options...
afterimage Posted October 5, 2019 Share Posted October 5, 2019 Try shielding copper foil Quote Link to comment Share on other sites More sharing options...
fretmeister Posted October 6, 2019 Share Posted October 6, 2019 Entirely normal. 1 pickup is a single coil and noisy. both in together makes a Humbucker. Nothing wrong with it. 2 Quote Link to comment Share on other sites More sharing options...
KiOgon Posted October 6, 2019 Share Posted October 6, 2019 This is worth reading - https://www.notreble.com/buzz/2015/04/15/solving-bass-hum-problems-grounding-vs-shielding/ 3 Quote Link to comment Share on other sites More sharing options...
NickA Posted October 6, 2019 Share Posted October 6, 2019 22 hours ago, afterimage said: Try shielding copper foil Shielding the control cavity won't help in this case as the noise is coming in from the pickups. You can shield the pickup cavities but it still leaves the front open. You could also shield against radiated interference by shielding the whole pickup ( surprised more pickups don't include an internal shield ).. but there is nothing much you can do about close field magnetic interference without also blocking the signal picked up from the strings ( and using thick plates of steel ). Copper Vs spray on conductive paint? Probably the same effect. Commercial basses almost all use paint and it works pretty well. Much easier to use than copper foil .. and less prone to gaps. Humbuckers = the way to go. 1 Quote Link to comment Share on other sites More sharing options...
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