Needing Help Wiring Passive PJ's

[Cory Jacobs]

The pickups in question are Seymour Duncan Quarter Pounder P and J.

I wish to keep my initial knob placement and functionality the same as it was before the switch to passive.
The knobs were: Volume, Blend/Balance, Stacked tone (Treble on top, Bass on bottom).

When turned clockwise, the blend would go to the neck (P) pickup; and when rotated counterclockwise, the bridge (J) pickup was favored. In the center detent, the pickups were out of phase and POWERFUL.

The both of the knobs on the stacked tone are center detented. Clockwise letting the pickup ring true, center detent being about halfway between true signal and the capacitor, and all the way counter-clockwise would be muddy as hell, essentially.

The tone knob(s) will incorporate two capacitors and are based on G&L's design for a passive 2 band tone control. [http://www.tonefiend.com/wp-content/uploads/GL-Tone-Circuit.jpeg] I'm pretty set on a .1uf for the bass and a .47uf for the treble, but I'm open to suggestion.

The output jack is stereo and I don't wish to replace it with a standard one (future modifications in mind). It simply has two grounds and a lead prong. I hope the workaround isn't too problematic.

Here is a link to an image of the factory wiring with the active setup. [[Invalid or Expired Link Removed]]

Please show all grounds if at all possible, I'm not very savvy at electronics yet.

Included is a very basic template of all the pots that can be used to draw out the schematic.

Thank you very much for your time.
C

 

[line6man]

All you need to do is take a standard VBT diagram, and add the bass cut.
[Invalid or Expired Link Removed]

Note that you have made exceptionally poor choices for your capacitances. At those values, you are going to end up with volume pots rather than EQ. The bass cut cap should be of a numerical prefix two orders of magnitude less capacitive than what you have specified. I would suggest 0.0047uF. The treble cut should also be much less capacitive. 0.047uF would be standard, but if you want extra darkness, try 0.068uF or 0.1uF.

 

[Cory Jacobs]

All you need to do is take a standard VBT diagram, and add the bass cut.
[Invalid or Expired Link Removed]

Note that you have made exceptionally poor choices for your capacitances. At those values, you are going to end up with volume pots rather than EQ. The bass cut cap should be of a numerical prefix two orders of magnitude less capacitive than what you have specified. I would suggest 0.0047uF. The treble cut should also be much less capacitive. 0.047uF would be standard, but if you want extra darkness, try 0.068uF or 0.1uF.

Here's what you're suggesting. Forgive my editing it, the way they had it laid out made me lose my train of thought every time I tried to read it. It is the same, save for the blend being rotated and the pegs being numbered for noob-status. I know it's quite easy to say "hey just add a bass cut" but I would definitely need (and greatly appreciate) help in actually drawing it out. Note that the method you suggested isn't in keeping with G&L's tone design, which calls for the '1' peg of the Bass pot to be connected to the '3' of the volume.

Second, I appreciate you know a great deal about capacitors, but there's no need to be a dick. I came out the the gate pretty humbly and you come at me with some neckbearded "please note your choices are terrible hurr perderr". Take it down a notch, Grand Wizard. We're all bassists here.

So you'd say a 0.0047uf for my bass cap and a 0.047 for treble?

 

[line6man]

Note that the method you suggested isn't in keeping with G&L's tone design, which calls for the '1' peg of the Bass pot to be connected to the '3' of the volume.

You're right, I didn't check the diagram beforehand, but they have the tone control misplaced. I'll draw a full diagram when I have time.

Second, I appreciate you know a great deal about capacitors, but there's no need to be a dick. I came out the the gate pretty humbly and you come at me with some neckbearded "please note your choices are terrible hurr perderr". Take it down a notch, Grand Wizard. We're all bassists here.

My apologies if it came off dickishly. That was not my intention. I was just pointing out that at those values, you might as well use a piece of wire instead of a capacitor.
Indeed you will want to use something in the neighborhood of 0.00XXuF for bass, and 0.0XXuF for treble.

 

[Cory Jacobs]

Nice. Thanks man! I appreciate it.

 

[line6man]

Here is your diagram.

A small note; I have drawn the diagram with the pickups in phase, as that is standard convention. In your particular case, wiring out of phase simply requires that you wire one pickup backwards, as your current setup is configured. However, I am fairly sure that you are mistaken about the relative phase of your pickups. Your factory wiring diagram indicates single conductor pickups wired in phase. Wiring single conductor pickups out of phase typically produces a lot of noise, as the shielding becomes the hot. Additionally, out of phase pickups do not produce a powerful tone. Quite the opposite, they are thin and weak. In any case, do what you want with the phase. It's easy to copy your existing wiring.

 

[Orange Caesar]

All you need to do is take a standard VBT diagram, and add the bass cut.
[Invalid or Expired Link Removed]

Note that you have made exceptionally poor choices for your capacitances. At those values, you are going to end up with volume pots rather than EQ. The bass cut cap should be of a numerical prefix two orders of magnitude less capacitive than what you have specified. I would suggest 0.0047uF. The treble cut should also be much less capacitive. 0.047uF would be standard, but if you want extra darkness, try 0.068uF or 0.1uF.

Omg... I should have asked this before rewiring again... I tried to experiment with a v/b/t... Center detente on the blend silenced both pickups... I dunno... Maybe they were out of phase or wrong cap or whatever... But I thought let's reroll... And of course rewired to v/v/t... And of course screwed something up... Probably... Wrong caps... Didn't even dawn on me... Well it might have, but I probably ignored it... Man... line6man... Your awesome...

 

[Cory Jacobs]

Hey thanks a ton, line6man. I appreciate it. But by all means, if anyone else wants to keep throwing ideas out there, I'd love to hear them. Always nice to have knowledge for later down the road.

 

[Cory Jacobs]

Hey everyone, My wiring guy is having problems with the diagram.
I provided one that was (to the best of my knowledge correct) and I showed him yours, Line6man.
He said no dice on either of them.

 

[line6man]

Hey everyone, My wiring guy is having problems with the diagram.
I provided one that was (to the best of my knowledge correct) and I showed him yours, Line6man.
He said no dice on either of them.

Well what is the problem?

 

[Cory Jacobs]

Well what is the problem?

not sure. Asked him. Hopefully I'll have an idea by tomorrow. This wiring diagram has been giving me serious trouble. You'd think in essence, Vol, Blend, Tone would be a snap; but I know from experience it's easier said than done. I tried wiring it myself many many times before outsourcing my work. Had everything working up to the blend and (limited) tone. My biggest issue was not being able to get rid of the hum by grounding everything together and in the proper order. Plus, the bass came stock with a stereo output jack, like I said earlier; which makes things even trickier as far as proper grounding. But it's a really fine quality jack, and it's kinda embedded into the bass, so i don't see replacing it to be an option.

story of my life, I tell you. I just wanna slap her around and this is the crap i gotta go through...

 

[Kieron Stirrup]

I have a 1995 Mexican pj with active pick ups that are in bad shape. By accident I have recently bought a passive set of 1/4 lb Seymour pick ups and want to fit them to my bass. The bass has 2 double stacked pots mounted on a board that i know I need to remove , so have sourced 2 replacements. I also have a mono 6mm jack socket and, like Corey, have 2 X .047 uf capacitors. If I wire the bridge pick ups to one stackable pot with a cappy to ground and the neck pick up to the second stackable the same way and take both feeds to the positive of the socket, would it cause a problem?