Push/Pull - Active/Passive Tone - OBP2

[chinjazz]

Hi,

I thought this would be a good sub-form to post this question.

Has anyone here done a J Bass wiring where you have a push/pull - Active/Passive tone set up with an OBP-2?

I came up with what I think to be a very convenient and flexible 3 knob concept, and am stuck on the push/pull p/a tone section.

Knob 1: Stacked Volume (for location convenience, and one handed fade ins)...

Knob 2: Push/pull (what I'm stuck on)

Knob 3: Stacked Bass/Treble (all wired up).

I'm looking at the AG diagrams, and one I got from best bass gear, and getting some feedback out in web land, and I'm confused.

Here's a photo of my Knob 2 currently in progress (or lack):

(1) Blue to OBP2
(2) Green (showing yellow)to OBP2
(3) Diagonal switch connect (not sure if this is needed)
(4) Connection from Stacked Volume
(5) to be cap to ground for tone....

Is this completely off to Mars, or off base?

Whatever anyone can help me with would be hugely appreciated!

Thanks!

 

[line6man]

Standard active/passive switching:

 

[chinjazz]

Hi Line6man,

Much appreciate your diagram

Wondering if I should view yours upside down based on what I show in my photo, as the vantage point does make a difference.

Is your diagram a standard DPDT switch, and do these push pull variations have the same layout?

Any thoughts on the other connections on the pot?

Thanks again!

 

[FBB Custom]

You haven't said exactly what you want the pot to do. Do you want it to do nothing when the bass is in active mode and be a tone knob when it is passive? Or do you want the tone pot to always be in the circuit?

 

[chinjazz]

You haven't said exactly what you want the pot to do. Do you want it to do nothing when the bass is in active mode and be a tone knob when it is passive? Or do you want the tone pot to always be in the circuit?

True, I hadn't explained fully.

I'd like the push/pull - a/p knob to be active pre amp in the down position by default, and when pulling it out to be in passive mode and a tone pot.

Almost identical to a Spector coda (except I've got 3 knobs: a stacked vol/vol for the pick ups, the push pull in question, and the last with stacked treb/bass):

Invalid Link Removed

I think turning this knob in active mode has no affect, but pulling it would provide the passive tone via capacitor (standard jazz)..

Hope this helps..

 

[FBB Custom]

I see. Well, if that's what you want to do then you won't be able to use that A/P diagram, as far as I can tell. I'm not sure why they have the preamp input going to ground in passive mode but if that's not important, there is an alternate A/P wiring that would allow you to do what you want. I'm not going to make you a GIF, but if the lugs are numbered:

P1 P2 P3
S1 S2
S3 S4
S5 S6

Where you are looking at the PP with the pot body on top, an Px are the pot's lugs, and Sx are the switch's lugs.

Connect S5 and S6.
S3 receives hot from volume.
S4 goes to the jack.
S1 goes the the preamp in.
S2 receives the preamp out.
S6 goes to the tone pot as hot and wire the tone pot as you would on any passive instrument.

 

[martinedwards]

This is good for me too.....

I'm building a bass with two preamps (from mag & piezo) blended, and I want a "whoops the battery is dead" switch for the mag pup......

 

[SGD Lutherie]

The problem with Line6mans's wiring, while correct for active/passive, is it doesn't leave room for switching the tone control in.

If you use this switching scheme:

[Invalid or Expired Link Removed]

Then you can use the other side of the switch to switch the passive tone control in.

I can draw up a schematic, but it wont be until later.

 

[chinjazz]

Thanks FBB and David! I'll examine all the info, and give the soldering gun a whirl tonight.

This is great actually! The whole passive tone option is a cool route in my opinion.

This made my researching much easier as you well know that web searches yield sketchy results sometimes. I'm always tweaking my basses but it's clearly not my mainstay (more of a web Dev and iOS guy)

I'll post progress/results.

Cheers and have a great weekend!

 

[line6man]

The problem with Line6mans's wiring, while correct for active/passive, is it doesn't leave room for switching the tone control in.

If you use this switching scheme:

[Invalid or Expired Link Removed]

Then you can use the other side of the switch to switch the passive tone control in.

I can draw up a schematic, but it wont be until later.

That's a terrible way to wire an active/passive switch!
The pickups are always connected to the preamp, so in passive mode, the input impedance of the preamp runs parallel to whatever you are plugging the bass into, basically halfing it.

Try this:

 

[chinjazz]

That's a terrible way to wire an active/passive switch!
The pickups are always connected to the preamp, so in passive mode, the input impedance of the preamp runs parallel to whatever you are plugging the bass into, basically halfing it.

Try this:

This looks a bit closer to what I originally had with the exception of my diagonal cross connect on the switch. And of course with the tone wiring add in. Perhaps this would do the trick? Thanks!

 

[chinjazz]

That's a terrible way to wire an active/passive switch!
The pickups are always connected to the preamp, so in passive mode, the input impedance of the preamp runs parallel to whatever you are plugging the bass into, basically halfing it.

Try this:

Hey Line6man,

I tried your version, and it worked perfectly!

This was great that you and everyone else provided me a way to solve this! Plus it's something I'll definitely use again.

You wouldn't happen to know if they're are even higher quality pots than what are typically supplied thru stumac, Ior allparts? Where to get them?

This one stacked vol/vol pot im using is a bit low quality. Slightly crackly, but still newish.

A

 

[edmund76]

That's a terrible way to wire an active/passive switch!
The pickups are always connected to the preamp, so in passive mode, the input impedance of the preamp runs parallel to whatever you are plugging the bass into, basically halfing it.

Try this:

I have an old Washburn that has a neck pickup, bridge pickup, 3-way spdt switch, and a push/pull tone pot to switch between active and passive mode that I bought at a garage sale. The previous owner tried to do something to it, I do not know what, and messed it up royally.
I found a wiring diagram to wire just the two volume pots, 3-way switch, and the tone pot, which work great in passive mode and I tried the above method to wire in the preamp to the push/pull tone pot. It works in switching from active to passive, but now the 3-way switch no longer works in either passive or active mode. I can no longer switch between the neck pickup or the bridge pickup and all I get is both.
Does anyone have a diagram that will allow the 3-way switch to work in both active and passive mode?
I appreciate any help that I can get.

 

[chinjazz]

I have an old Washburn that has a neck pickup, bridge pickup, 3-way spdt switch, and a push/pull tone pot to switch between active and passive mode that I bought at a garage sale. The previous owner tried to do something to it, I do not know what, and messed it up royally.
I found a wiring diagram to wire just the two volume pots, 3-way switch, and the tone pot, which work great in passive mode and I tried the above method to wire in the preamp to the push/pull tone pot. It works in switching from active to passive, but now the 3-way switch no longer works in either passive or active mode. I can no longer switch between the neck pickup or the bridge pickup and all I get is both.
Does anyone have a diagram that will allow the 3-way switch to work in both active and passive mode?
I appreciate any help that I can get.

Hey Edmund,

I'm definitely not an expert, and got mine working by some trial and error. With Your 3 way switch, you want it to switch to your front pick up, turning off the rear, middle position to have both pickups on, and the rear position just turn on the bridge pickup? Either way, I'm sure there's a way to get it done. Maybe we can get some other folks to chime in.

A

 

[line6man]

I have an old Washburn that has a neck pickup, bridge pickup, 3-way spdt switch, and a push/pull tone pot to switch between active and passive mode that I bought at a garage sale. The previous owner tried to do something to it, I do not know what, and messed it up royally.
I found a wiring diagram to wire just the two volume pots, 3-way switch, and the tone pot, which work great in passive mode and I tried the above method to wire in the preamp to the push/pull tone pot. It works in switching from active to passive, but now the 3-way switch no longer works in either passive or active mode. I can no longer switch between the neck pickup or the bridge pickup and all I get is both.
Does anyone have a diagram that will allow the 3-way switch to work in both active and passive mode?
I appreciate any help that I can get.

I can draw you one, but the problem is unrelated to the active/passive switching. You have the pickups hardwired in parallel somehow. Have you checked the circuit with an Ohm meter?

 

[edmund76]

Thanks for the quick responses fellas, sorry that I was not as quick. I have not checked the circuit with an ohm meter, I will do that when I get home.
This is the diagram that I used to wire up the bass for passive mode, [Invalid or Expired Link Removed], then I used your diagram to wire in the active part Line6man. I ran a wire from each volume pot to the middle pin on the left side of the push/pull tone pot. Now that I think of, that is the problem isn't it? Should I have ran the middle pin of the 3-way switch to the middle pin on the left side of the push/pull pot?
Thanks again for your time and help.

 

[edmund76]

I figured out what I did wrong. I was taking the output from both volume pots and tying them to the middle pin on the left side of the push/pull tone pot and not the output from the 3-way switch.
I removed the wires coming from the volume pots output and wired the output from the middle pin on the 3-way switch to the middle pin on the left side of the push/pull tone pot and that fixed my problem.
After I read what you asked me Line6man, I realized what I did wrong.
Thanks again for your time and help.

 

[chinjazz]

Line6man is da Man!

 

[edmund76]

I agree with you Chinjazz, Line6man is the man.
Thanks again for the help.

 

[ZolkoW]

Try this:

This is what I'm using all the time... Does the other version have any advantage to this? for example, less popping noise when switching?
On my amp this has almost no noise when swiching (maybe sometimes the first switch makes noise, but after that it's virtually silent), but I found that some amplifiers behave other than that..