Wiring a PJ Bass for Bi-Amping

[Bassmaster_Gnl]

I have a PJ Bass and I was interested in installing a stereo jack so that I can separate the output from each pickup for bi-amping. I already have two CTS push-pull pots installed which I'm keen to make use of, can anyone tell me whether the wiring scheme in the diagram work? I've omitted some grounding for the bridge/cavity etc. The idea was to have a volume knob for each pickup, plus an additional tone knob for the precision pickup. One of the P/P switches would act as a high cut for the precision pickup (with the help of a .01 uF capacitor), while the other toggles between a standard mono output, or sending the precision tone to the 'ring' of the stereo jack. I've looked to a diagram of Billy Sheehan's setup for inspiration, but I'm not sure if it'll work. Any thoughts?

 

[SulzerType2]

I don't have anything much to add beyond that the wiring looks fine.

 

[LoveThatBass]

As wired the switches will not work.They are like 2 separate spdt switches meaning the left side is one switch and the right side another with the center lug of each being common to that side.
Also you want to solder the ground end of the cap to back of pot as having it dangle in mid air connected to a ground wire will eventually break due to vibration
In addition the Tone pot is not correct. I could draw one but it would be later on

 

[Bassmaster_Gnl]

As wired the switches will not work.They are like 2 separate spdt switches meaning the left side is one switch and the right side another with the center lug of each being common to that side.
Also you want to solder the ground end of the cap to back of pot as having it dangle in mid air connected to a ground wire will eventually break due to vibration
In addition the Tone pot is not correct. I could draw one but it would be later on

Thanks for pointing that out about the switches, I always seem to make that mistake! As for the caps, I do plan to solder them to the backs of the pots, its just that I'm struggling to get to grips with the software I drew it with so I did it that way! Can you give me a vague idea what's wrong with the tone pot?

 

[LoveThatBass]

Tone should be wired similar to this:

You can either wire cap on outer lug like above or put it on the the center lug and put the wires on that outerlug. I usually wire it with the cap on the middle lug but 6 of one 1/2 dozen another. I guess if you have the tone pot facing the output jack then easier to wire this way. If you turn it 180 facing the other pots then easier to have wires on outside and cap in middle. There is one lug left open. Do not ground it.

 

[MidlifeBeginner]

Beware that when you biamp, you need to worry about ground loops. If you connect grounds from two amps together in your bass, and the amps are each separately connected to AC ground, there is a ground loop. A ground loop is a big antenna for picking up noise.

If both amps are plugged into the same AC outlet, you might not notice noise problems.

 

[Bassmaster_Gnl]

Tone should be wired similar to this:
View attachment 4971796


You can either wire cap on outer lug like above or put it on the the center lug and put the wires on that outerlug. I usually wire it with the cap on the middle lug but 6 of one 1/2 dozen another. I guess if you have the tone pot facing the output jack then easier to wire this way. If you turn it 180 facing the other pots then easier to have wires on outside and cap in middle. There is one lug left open. Do not ground it.

Thanks, I'll make sure to do it that way instead.

Beware that when you biamp, you need to worry about ground loops. If you connect grounds from two amps together in your bass, and the amps are each separately connected to AC ground, there is a ground loop. A ground loop is a big antenna for picking up noise.

If both amps are plugged into the same AC outlet, you might not notice noise problems.

Thanks for the warning, I think it should be okay with the way I have my amps set up!

 

[LoveThatBass]

Thanks, I'll make sure to do it that way instead.



Thanks for the warning, I think it should be okay with the way I have my amps set up!

If you do have hum issues there are isolation boxes available.

 

[secondbestcody]

Couldn’t you just use the Billy Sheehan wiring diagram? Isn’t his bass wired this way? Not being sarcastic if it comes off that way.

https://d2emr0qhzqfj88.cloudfront.net/s3fs-public/diagrams/WDRL1_Relentless_SheehanStereo_2.pdf

 

[LoveThatBass]

Couldn’t you just use the Billy Sheehan wiring diagram? Isn’t his bass wired this way? Not being sarcastic if it comes off that way.

https://d2emr0qhzqfj88.cloudfront.net/s3fs-public/diagrams/WDRL1_Relentless_SheehanStereo_2.pdf

Pretty cool!

If he wanted to use a single stereo cable as I think he had in mind he could tie the mono/stereo from second pickup pot/switch to the ring terminal. Neck pickup circuit to the tip and grounds to the sleeve of the output jack.

 

[JeezyMcNuggles]

I have a PJ Bass and I was interested in installing a stereo jack so that I can separate the output from each pickup for bi-amping. I already have two CTS push-pull pots installed which I'm keen to make use of, can anyone tell me whether the wiring scheme in the diagram work? I've omitted some grounding for the bridge/cavity etc. The idea was to have a volume knob for each pickup, plus an additional tone knob for the precision pickup. One of the P/P switches would act as a high cut for the precision pickup (with the help of a .01 uF capacitor), while the other toggles between a standard mono output, or sending the precision tone to the 'ring' of the stereo jack. I've looked to a diagram of Billy Sheehan's setup for inspiration, but I'm not sure if it'll work. Any thoughts?

I don't understand the purpose of this.

Both pickups will just be sent as a single "balanced" signal. Same as having them wired to a single mono jack. Nothing will change at all. It's one cable. One cable, one input on the board.

Are you planning on feeding this into a "stereo to dual mono" splitter, and then out to two seperate amps?

Are you trying to split your highs and lows?

I don't understand.

If you are trying to seperate the pickups, like on a rickenbacker, you need two jacks. Two jacks, two cables. That's stereo. Left, and right. Two cables.

If you just want to isolate the P pickup, turn the volume knob off on the J pickup. I use an on/off switch on mine. I just find it easier/faster, and it let's me keep the two knob set up.

 

[Bassmaster_Gnl]

I don't understand the purpose of this.

Both pickups will just be sent as a single "balanced" signal. Same as having them wired to a single mono jack. Nothing will change at all. It's one cable. One cable, one input on the board.

Are you planning on feeding this into a "stereo to dual mono" splitter, and then out to two seperate amps?

Are you trying to split your highs and lows?

I don't understand.

If you are trying to seperate the pickups, like on a rickenbacker, you need two jacks. Two jacks, two cables. That's stereo. Left, and right. Two cables.

If you just want to isolate the P pickup, turn the volume knob off on the J pickup. I use an on/off switch on mine. I just find it easier/faster, and it let's me keep the two knob set up.

The idea is to use a splitter box to feed two amps, that way I can have the low end from the precision pup going to a bass amp and keep that clean, with the more trebly tone from the jazz pup going to a guitar amp, with some distortion. Hope I've got that the right way round haha!

 

[Bassmaster_Gnl]

Couldn’t you just use the Billy Sheehan wiring diagram? Isn’t his bass wired this way? Not being sarcastic if it comes off that way.

https://d2emr0qhzqfj88.cloudfront.net/s3fs-public/diagrams/WDRL1_Relentless_SheehanStereo_2.pdf

I've been doing some thinking and I probably will wire it this way, with the Vol, Tone, Vol configuration (except with a TRS jack rather than the dual jack setup). Hard to go wrong if I just copy the diagram, plus I'm not sure whether I've got the high cut switch right on the one that I posted (not entirely sure how it works anyhow!).

 

[StereoPlayer]

The idea is to use a splitter box to feed two amps, that way I can have the low end from the precision pup going to a bass amp and keep that clean, with the more trebly tone from the jazz pup going to a guitar amp, with some distortion. Hope I've got that the right way round haha!

I’ve been doing this for years, just wire it up like two separate basses. Each output goes to the tip and ring of the stereo output jack. The tip is generally used for the treble pu.
You’ll love it.
My mini stereo rig and bass.

 

[LoveThatBass]

The idea is to use a splitter box to feed two amps, that way I can have the low end from the precision pup going to a bass amp and keep that clean, with the more trebly tone from the jazz pup going to a guitar amp, with some distortion. Hope I've got that the right way round haha!

Cool, let us know how it does!

 

[JeezyMcNuggles]

The idea is to use a splitter box to feed two amps, that way I can have the low end from the precision pup going to a bass amp and keep that clean, with the more trebly tone from the jazz pup going to a guitar amp, with some distortion. Hope I've got that the right way round haha!

Okay.

You could just get one of these, and put it at the end of your board.

SX21 Tiny Two-Way Crossover | Sweetwater

But, here's the splitter I was talking about. And, it's 25 bucks.

Invalid Link Removed

 

[IanStephenson]

I ran something like this for a few years in various configurations. It works great. I had two mono jack sockets and a single pan knob which controlled the relative volume - which I always left dead centre anyway!

Sometimes I ran into two amps, but as I streamlined it, I ended running both into a stereo compressor, then the high end through some kind of multifx/distortion/pre, then mixing them together before putting them into a power amp. It definitely avoids the loss of bottom end that fx can introduce.,

I stopped using it when I switched the FX to a Blue Thunder. It had a high pass filter before the fx, then mixed a low pass of the original signal back in, giving a similar effect for less effort. Not quite as good/versatile but close enough to carry to bar gigs every weekend!

Now I'm playing a different genre, and don't use any of that kit, but for all out in your face rock it was great!

have fun!

 

[IanStephenson]

Tried to edit and attach this, but I think it failed!

 

[Bassmaster_Gnl]

I’ve been doing this for years, just wire it up like two separate basses. Each output goes to the tip and ring of the stereo output jack. The tip is generally used for the treble pu.
You’ll love it.
My mini stereo rig and bass.
View attachment 4972318

Nice rig! Glad to hear that it worked well for you.

Cool, let us know how it does!

I will do.

Okay.

You could just get one of these, and put it at the end of your board.

SX21 Tiny Two-Way Crossover | Sweetwater

But, here's the splitter I was talking about. And, it's 25 bucks.

Invalid Link Removed

That crossover looks like a solid option. Obviously I'll try separating the pickups first and see if that works for me. Thanks for the recommendations though. That splitter pedal looks good too, and for a shockingly good price!

I ran something like this for a few years in various configurations. It works great. I had two mono jack sockets and a single pan knob which controlled the relative volume - which I always left dead centre anyway!

Sometimes I ran into two amps, but as I streamlined it, I ended running both into a stereo compressor, then the high end through some kind of multifx/distortion/pre, then mixing them together before putting them into a power amp. It definitely avoids the loss of bottom end that fx can introduce.,

I stopped using it when I switched the FX to a Blue Thunder. It had a high pass filter before the fx, then mixed a low pass of the original signal back in, giving a similar effect for less effort. Not quite as good/versatile but close enough to carry to bar gigs every weekend!

Now I'm playing a different genre, and don't use any of that kit, but for all out in your face rock it was great!

have fun!

Thanks for sharing, feeling very positive about my plans now. Just waiting for some parts and I'm gonna get it done ASAP...

View attachment 4972396
Tried to edit and attach this, but I think it failed!

Nice pic, I can see that it's had some use! In a good way...

 

[Callused Finger]

ABY switch

Can make one using 2 DPDT switches and 3- 1/4” jacks.