Wiring Help P/MM Bass

[baynes123]

I'm building a new Bass, my first, after having built std. electrics for a number of years. I have a body routed with a MM at the bridge and P or J in the neck - probably will go with a P. the body is currently routed for a single 9v battery, but I can easily double up if necessary [suggestions]. I need a wiring diagram to make the MM active [with a pre amp] and the P Passive [have heard P pups don't do too well active?] with the ability to switch between the 2 and mix if necessary. Can easily go with 4 control knows as body is routed for a jack....please help!!!

 

[line6man]

You can't do that. The pickups needs to be of similar output impedance to work together. Buffering with a preamp will cause one pickup to basically short the other out. Additionally, you will find that when soloing pickups, one pickup will have a constant input impedance, while the other will see variations in input impedance, as different cables and amps/effects are used. This is not very practical. A better way to do things is to buffer both pickups. This will give you all of the usual advantages of buffered signal paths, but also help to prevent the wonkiness of trying to blend the two dissimilar pickups.

 

[baynes123]

You can't do that. The pickups needs to be of similar output impedance to work together. Buffering with a preamp will cause one pickup to basically short the other out. Additionally, you will find that when soloing pickups, one pickup will have a constant input impedance, while the other will see variations in input impedance, as different cables and amps/effects are used. This is not very practical. A better way to do things is to buffer both pickups. This will give you all of the usual advantages of buffered signal paths, but also help to prevent the wonkiness of trying to blend the two dissimilar pickups.

Thanks for your help...as you can tell I'm no wiring guy, so not sure how to buffer both pick-ups? do you have a suggested wiring diagram I could follow or can you point me to a site where I can get a download a version. The one I currently have is below, but not sure its the best?

 

[line6man]

Thanks for your help...as you can tell I'm no wiring guy, so not sure how to buffer both pick-ups? do you have a suggested wiring diagram I could follow or can you point me to a site where I can get a download a version. The one I currently have is below, but not sure its the best?

You will need to choose a method of buffering. This can be done with onboard preamps, or simple FJET or opamp based circuits.

I'm not sure what the intention was with that diagram, but there are two tone controls parallel to each other. This is useless and overcomplicated. A better approach is to use a switch to select between capacitors, rather than increase the capacitance by using two tone controls.