Adding Passive Tone To Aguilar OBP-2

[hilde]

I am updating my Spector Ethos 4 that currently has an Aguilar OBP-2. I ordered new pots from Fat Bass Tone and am using one of their diagrams but would like to add a passive tone pot . On the Aguilar website they say to add the passive tone to the blue wire between the Vol pot ad OBP-2. But with an active/passive push-pull the tone pot would only work in active and not passive as I would like it to do. (or so I believe) So I want the tone pot to work in both passive and passive, I have a couple of questions.
1. Which wire do I connect the tone pot to and to which lug on the pot?
2. On which lug of the tone pot do I connect the cap?
Thanks all for your help

 

[bholder]

I'd put it last in the chain, on the green wire from the volume push/pull switch to the output jack tip.

 

[bholder]

Between the two red Xs I added:

 

[hilde]

Between the two red Xs I added:

View attachment 7112101

I was also wondering about the brown vice the green?

 

[Crater]

I'd put it last in the chain, on the green wire from the volume push/pull switch to the output jack tip.

No sir, that's incorrect. For the passive tone control to work, it's got to be connected on the "high impedance" side (passive) before the preamp input. Correct place is brown wire from the blend pot or volume control to the passive tone control.

If the tone control is placed after the preamp, it will work normally in passive mode but have very little effect when the preamp is on, as the preamp's lower impedance output signal will "blast through" the passive treble control.

But with an active/passive push-pull the tone pot would only work in active and not passive as I would like it to do. (or so I believe)

Aguilar's instructions have the passive tone working in both active and passive modes.

 

[bholder]

No sir, that's incorrect. For the passive tone control to work, it's got to be connected on the "high impedance" side (passive) before the preamp input. Correct place is brown wire from the blend pot or volume control to the passive tone control.

If the tone control is placed after the preamp, it will work normally in passive mode but have very little effect when the preamp is on, as the preamp's lower impedance output signal will "blast through" the passive treble control.


Aguilar's instructions have the passive tone working in both active and passive modes.

That's what I get for winging it, I did not consider the change from high to low impedance. I stand corrected. Oops. Sounded pretty good, but left out a small elephant...

 

[hilde]

No sir, that's incorrect. For the passive tone control to work, it's got to be connected on the "high impedance" side (passive) before the preamp input. Correct place is brown wire from the blend pot or volume control to the passive tone control.

If the tone control is placed after the preamp, it will work normally in passive mode but have very little effect when the preamp is on, as the preamp's lower impedance output signal will "blast through" the passive treble control.


Aguilar's instructions have the passive tone working in both active and passive modes.

Thanks for the clarification.

 

[Melt in the Sun]

Did you do this? If so, how did it work? Considering the same...

 

[hilde]

I did, and it came out great. Tone works in both passive and active. I switched out all the pots with CTS with the exception of the stacked Bass/Treble pot which is a Bournes from Fat Bass Tone. I also decided I prefer a Vol/Vol instead of a Vol/Blend setup. I had to pre fit the pots because of the long barrel jack, since I needed to have a volume next to/under the jack because of the height of the other pots and I also wanted the stacked B/T on the bottom since it was taller than the rest of the knobs. It only took about three minutes to get used to the new layout. The diagram below is my final layout. Not to scale but in the proper location. To keep the diagram a little cleaner I did not line in the Bass/Treble to the OBP-2, but I marked them on the pot. Also not shown in the diagram is that all the pots are grounded to each other.