Hi there,
I have an Fender American Deluxe Active Jazz Bass from 2004. Im the original owner, its always lived in studios, and overall I have really liked the thing. Its always been rather quiet noise wise, but in certain situations develops buzz so I decided to shield it. I also decided to install an active / passive switch, for which I did much reading on this forum (thanks for all the great info!).
The shielding worked great, the bass is dead quiet now. Also the active passive switch works great! (I think. . . ). The problem is the neck and bridge pickup are out of phase with each other, and I can't figure out why... My first thought was that I had installed a pickup backwards or something, because the wiring was correct. So I changed its orientation, but this did not change the phase. After much inter web searching I finally decided to swap one of the pickups lead and ground wires. I read from multiple sources that this would flip the phase for a pickup like mine which only has 2 wires; a lead and a ground. I reluctantly whipped out the soldering iron and swapped the lead and ground of the neck pickup. I left the bridge pickup as is. But for some reason, there was no change whatsoever to the phase! Im so confused. . . Can anyone shed some light on this?
More info regarding the bass:
This model was Active only to begin with
Its the kind with 1 main volume pot, a pan pot to blend between the neck and bridge, and low / mid / high eq.
The pickups are SCN (Samarium Cobalt Noiseless) and they have 2 wires, a lead and a ground
The pickups are wired to the pan pot first, then off to the active electronics
The volume pot is soldered directly to the preamp pcb
I used a DPDT Mini Toggle switch to do the active / passive thing. It was wired after the pan pot, and I used a wiring configuration that I believe is called a "Grounded True Bypass”. Here is a diagram, just substitute the “Effect send / return” for “Preamp in / out”:
So the switch works in such a way where in Passive mode, the only control I have is the blend between pickups. I knew this going in, and thats totally fine with me (its all I wanted anyways). Everything else remains the same on the active side, and seams to work fine aside from this polarity issue.
I am testing polarity via the screwdriver method, and am using my DAW to look at the waveforms. I perform multiple different tests to make sure Im not just goofing up the test somehow. Also, the only reason I perform the test in the first place is because something is obviously wrong with the sound of the pickups blended, but they sound great by themselves.
Did I goof with this wiring? What could be causing the pickups to be out of phase, and is there an easy phase flipping fix? Let me know if you need more info, and thanks so much in advance for any help!
Chase
I have an Fender American Deluxe Active Jazz Bass from 2004. Im the original owner, its always lived in studios, and overall I have really liked the thing. Its always been rather quiet noise wise, but in certain situations develops buzz so I decided to shield it. I also decided to install an active / passive switch, for which I did much reading on this forum (thanks for all the great info!).
The shielding worked great, the bass is dead quiet now. Also the active passive switch works great! (I think. . . ). The problem is the neck and bridge pickup are out of phase with each other, and I can't figure out why... My first thought was that I had installed a pickup backwards or something, because the wiring was correct. So I changed its orientation, but this did not change the phase. After much inter web searching I finally decided to swap one of the pickups lead and ground wires. I read from multiple sources that this would flip the phase for a pickup like mine which only has 2 wires; a lead and a ground. I reluctantly whipped out the soldering iron and swapped the lead and ground of the neck pickup. I left the bridge pickup as is. But for some reason, there was no change whatsoever to the phase! Im so confused. . . Can anyone shed some light on this?
More info regarding the bass:
This model was Active only to begin with
Its the kind with 1 main volume pot, a pan pot to blend between the neck and bridge, and low / mid / high eq.
The pickups are SCN (Samarium Cobalt Noiseless) and they have 2 wires, a lead and a ground
The pickups are wired to the pan pot first, then off to the active electronics
The volume pot is soldered directly to the preamp pcb
I used a DPDT Mini Toggle switch to do the active / passive thing. It was wired after the pan pot, and I used a wiring configuration that I believe is called a "Grounded True Bypass”. Here is a diagram, just substitute the “Effect send / return” for “Preamp in / out”:
So the switch works in such a way where in Passive mode, the only control I have is the blend between pickups. I knew this going in, and thats totally fine with me (its all I wanted anyways). Everything else remains the same on the active side, and seams to work fine aside from this polarity issue.
I am testing polarity via the screwdriver method, and am using my DAW to look at the waveforms. I perform multiple different tests to make sure Im not just goofing up the test somehow. Also, the only reason I perform the test in the first place is because something is obviously wrong with the sound of the pickups blended, but they sound great by themselves.
Did I goof with this wiring? What could be causing the pickups to be out of phase, and is there an easy phase flipping fix? Let me know if you need more info, and thanks so much in advance for any help!
Chase
