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How to add passive tone control to active/passive bass??

#2
You can run it parallel to the output of the blend pot.

That is not the proper way to wire an active/passive switch.
Do it like this.
4065969204_e9e0cb5e54_o.png
 
#4
You can't install an active passive switch like that because the volume control is 25K and wont work with the passive pickups.

So you need to replace the volume control with a higher value, like 250K or 500K, but that might not work well with the preamp.

The best solution is to wire the blend control to a 250K or 500K volume pot, and then to the input of the preamp. Take the output of the preamp and run it to the active passive switch, and not to a volume pot.

The passive tone control would wire up to the new volume pot, or at the output of the blend control.

Also that active passive switch you have is wrong. What you want to do is take the wire from the blend/new volume pot and switch it from the input of the preamp to the output jack. At the same time disconnect the output of the preamp from the output jack. It's also a good idea to switch the input of the preamp to ground when switching to passive.

Before you do all that you should make sure you actually like the sound of the pickups passive. So temporarily disconnect the output from the blend to directly to the jack (with the preamp disconnected from the jack). Then you will hear what the pickups sound like passive. Passive is not always better.
 
#5
SGD Lutherie said:
Also that active passive switch you have is wrong.
Click to expand...

Exactly.

That switching will not work in any bass, because the volume pot is after the switch. Because of the impedance differences between the active and passive modes, either the volume will have no effect in active mode until the end of the rotation, or the passive mode will have very little output, depending on whether the pot value is high or low.

For proper active/passive switching, you need a pot value appropriate for the higher impedance passive pickup signal ran before the switch and input of the preamp.
 
#7
Oh, sorry just saw what Line6man put. and thinking about it, it is pretty quiet in passive.

Could, when you have time, you try and draw up a wiring diagram of what you are saying i should do?

im not sure i understand :S

sorry to be of bother.
 
#8
keytthom said:
Oh, sorry just saw what Line6man put. and thinking about it, it is pretty quiet in passive.

Could, when you have time, you try and draw up a wiring diagram of what you are saying i should do?

im not sure i understand :S

sorry to be of bother.
Click to expand...

I can't see your original diagram any longer, the link is broken.

What you want is a simple volume-blend-tone setup with an active/passive switch, right?
 
#10
line6man said:
Exactly.

That switching will not work in any bass, because the volume pot is after the switch. Because of the impedance differences between the active and passive modes, either the volume will have no effect in active mode until the end of the rotation, or the passive mode will have very little output, depending on whether the pot value is high or low.

For proper active/passive switching, you need a pot value appropriate for the higher impedance passive pickup signal ran before the switch and input of the preamp.
Click to expand...

I started writing my reply, got sidetracked emailing my wife her shopping list she left on the table here (smart phones are wonderful!) and then you come along with your one thousand and one wiring diagrams, just as I hoped you would.

You have quite a nice collection there. :D
 

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