3 Pickup Bass Phase Issue Questions

[JEDI BASS]

I'm still as confused as everyone else about why you even have this issue in the first place. There are lots of 3-pickup guitars out there (even some with one humbucker and two single coils!) with the capability to combine all three pickups and/or various combinations of two at once without needing a phase switch.

I appreciate the input.

But, actually, almost everything I’ve read in the last few days about phase issues were articles about 3 pickup strats. Do some looking around online. I have a hot soldering iron and my bass in pieces at the moment, so I don’t want to spend the time to re-find and paste the info.

Also, Carl Pedigo has been with Lākland since they were in Dan Lakin’s tire shop. And he’s built 3 pickup basses before. He knew there’d be a phase issue and he tried everything everyone has suggested so far, before we ever settled on the two output fix. I only started this thread because a friend who’s an electronics guru, pickup designer, and tube amp builder thought that there had to be a remedy. Looks like he was right.... phase switch.

 

[ctmullins]

Apologies for belaboring my point, but - The fact is, if the neck and middle are in phase, and the neck and bridge are in phase, then the bridge and middle are also necessarily in phase.

I’m wondering if what you’re hearing might not be phase related, but rather due to the large spread between your pickups? But then no, other instruments (like Höfners and Gretsches) wouldn’t work either.

I have made a few three-pickup instruments myself, and have had no such issues, but I’ve used three identical pickups. Perhaps there’s some sort of impedance mismatch between the P and the lipstick? Then you would expect both lipsticks to behave similarly, but they don’t...

There is a simple technique to test the phase of each pickup individually, if you have (access to) an analog multimeter. With the hot lead connected to the red probe, and the ground lead connected to the black probe, hold a screwdriver stationary over the top of the pickup, then quickly jerk it away, while watching which way the needle swings on the multimeter. If the needle swings the same way for the different pickups, they have the same phase.

 

[JEDI BASS]

Apologies for belaboring my point, but - The fact is, if the neck and middle are in phase, and the neck and bridge are in phase, then the bridge and middle are also necessarily in phase.

I’m wondering if what you’re hearing might not be phase related, but rather due to the large spread between your pickups? But then no, other instruments (like Höfners and Gretsches) wouldn’t work either.

I see your point now. I do recall reading about how the distance between pickups affects phase. At this point, I really don’t have many options except to try the phase switch, and see what happens.

 

[bassdude51]

I had a P + J bass. The P neck pickup was a Duncan and the J bridge pickup was a Fender. I wired it properly but it sounded like crap. Found out that the Duncan and Fender were out of phase (winding direction and/or magnet polarity was different or something). Switched the ground and hot wires on the Duncan.............fixed it!

We hope that you get 'er figured out. SUPER NICE BASS!!!!!!!!!!!!!!

 

[JEDI BASS]

First of all, HUGE THANKS to everyone for their help! It’s always a blessing when different opinions and ideas can be shared without any rudeness or smart remarks. That’s when real progress and problem solving start to happen! That said... I have to admit being wrong. It turns out that the volume drop that occurred when playing both lipsticks together (leaving the P out of the equation) was actually an indication of a phase issue between the 2 lipsticks. The EMG BTC HZ’s active balance control (ABC) did help some with it, but not enough that I didn’t check at least 3 different times to make sure I had the right components.

According to my research, the distance between pickups can cause or remedy some phase issues. So, my theory is that the distance between the lipsticks helped mask the phase issue just enough that it eluded both Carl and I. I called Carl just now, and he said his bass amp at the shop was not working at the time, so he was using a guitar amp to test my bass. That was also a factor in him not hearing the phase issue.

How did I discover all this?? Dumb luck honestly! I did install the phase switch on the neck pickup, and I flipped the EMG solderless connections for both the bridge and the neck lipstick, thinking (wrongly) that would put the bridge Lipstick in phase with the P and leave the 2 lipsticks in phase with each other. Then my switch could be flipped to make the neck lipstick in phase with the P, when needed. After all this work, about 6 hours cause I’m slow and methodical and made some mistakes, I left all the guts hanging out and put the neck back on with just 2 strings mounted. I quickly noticed that with the switch ON in one position, everything was in phase. I did not expect that! And of course, the bass sounded like butt with the phase switch flipped. I put the bass completely back together and verified that there’s no phase issues at all until I flip the switch to the other position.

BUT, now I have another issue. The lipsticks each have a chassis ground wire, and positive and negative wires coming out of the pickup. When I soldered them to the EMG solderless plugs, I soldered the chassis ground and negative to the EMG negative. And the positive to positive. EMG preamp doesn’t like that I’ve flipped the plugs over and apparently it screwed up the grounding of the pickups. I get a lot of “you’re not grounded” noise, especially from the bridge L and it pops when I touch the pickup. I’m going to flip both connectors back over, the way the preamp instructions show, and see what happens.

 

[dwizum]

If I were in your shoes, I would run the positive and negative from the pickup to the EMG wiring harness and or your phase swith or other wiring, and then run the shielding ground from the pickups straight to the ground lug on the jack, separately.

If you run the shielding ground from the pickup to the EMG harness, and then you flip flop phases, you're basically including your shielding in the signal side of the circuit instead of the ground side, any time that pickup is phase flipped.

 

[JEDI BASS]

If I were in your shoes, I would run the positive and negative from the pickup to the EMG wiring harness and or your phase swith or other wiring, and then run the shielding ground from the pickups straight to the ground lug on the jack, separately.

If you run the shielding ground from the pickup to the EMG harness, and then you flip flop phases, you're basically including your shielding in the signal side of the circuit instead of the ground side, any time that pickup is phase flipped.

True! But, that would be a lot of work considering the hours I’ve already spent soldering this monster together. If I have to, I will though.

 

[JEDI BASS]

AAAAAAAAANNNNNNNNDDDDDDDD...... a quick flip of one, then both pickup connectors and its apparent that I’ll need to break out the soldering iron again and do what @dwizum suggested.

Argh!!! Oh well, I always have to learn every #*%#ing thing the hard way! I can feel my third headache of the day already coming on.

 

[charlie monroe]

Hang in there man.

 

[ctmullins]

Progress!

 

[JEDI BASS]

Thanks guys! It wasn’t that hard to fix. I simply found the right orientation for the solderless pickup connections that yielded no phase issues. Both had to be flipped over (reversed). And, that left the bridge pickup sounding ungrounded. Neck pickup is quiet. So, I spliced a wire into the ground running to the jack and fed that through to the bridge pickup, de-soldered the chassis ground wire, cut it off and taped the end. Then soldered the new wire to the pickup chassis. That was the simplest fix.... no more ground issue. If I flip the phase switch, which I never will cause out of phase equals YUCK, the neck pickup starts sounding ungrounded.

In the end, if the phase issue had been more easily diagnosed, this bass could have had just 1 output jack. But, I think I’m happier with it the way it is! There’s such a volume discrepancy with the quiet lipsticks and bombastic Relentless P, that I prefer having the active mixer on my board fixing that issue. Now, all the volumes on the bass can’t be at 10, and I don’t have to think about it. I can just have fun with the P’s tone and the lipstick’s preamp.

 

[JEDI BASS]

Here she is after I gave her the switch, haha! It’s barely noticeable, it’s so tiny!

 

[dwizum]

Great work! It's always satisfying when you get to a point of comfort after a perplexing problem.

 

[JEDI BASS]

Great work! It's always satisfying when you get to a point of comfort after a perplexing problem.

Thanks, and yes it is!

 

[BrickBatMansion]

Hello All you Devils! Long time no type............hope everybody is well!
@JEDI BASS :how are the 3 pups doing in that red P? Is the middle pup worth the hype?
@Jeff Roller : Where is Pappy's and what day do you play there?

 

[Jeff Roller]

Pappy's is in Crossville, show is 2/26 @ 9pm central time.

 

[JEDI BASS]

@JEDI BASS :how are the 3 pups doing in that red P? Is the middle pup worth the hype?

I’ve rehearsed the Red B!+ch with the band twice, and it did not disappoint at all! The Relentless P pickup sounds amazing, as expected. Being a fan of the Dimarzio Model P, I expected that I’d love it.

I’ll be gigging with it at Ridge Runners in Oak Ridge in two days, Saturday 2/27 9p-1a.

 

[ChristoMephisto]

Could try what they did in the 60s before RWRP was a thing is to put one pup in series with a large cap .1uf for example.
It forces the pickup to be "half out of phase" with the other pups but doesn't effect the low end
Out of phase is when one pup is 180 degrees and the cap causes it to lag by 90 degrees, hense the half out of phase term. Something Bill Lawrence used

 

[iiipopes]

Remember if you have two identical pickups in parallel dimed, you will have half the inductance than with one dimed. This can cause a volume drop. It is infamous on Jazz basses. On those instruments where I get a volume drop from the impedance drop (after checking the polarity of the pickups) is to put a .01 microfarad capacitor in-line from the hot lead of the bridge pickup to its volume control. This lowers the output of the pickup just a little bit from cutting some lows, although the lows coming out of a bridge pickup are essentially non-existant due to the less string excursion closer to the bridge, but the upside is that there is clarity of the low end from the pickups not fighting each other on the comb filtering of the fundamental and certain overtones, and there is no volume loss to the neck pickup when it is dimed along with the bridge pickup dimed.

So there are actually several reasons the volume can drop when two or more pickups are dimed together:
1) actual phase issues, whether with the direction of the wind of the coil or the polarity of the magnet(s);
2) comb filtering inherent in the placement of pickups;
3) impedance drop from two or more pickups dimed in parallel.

Note that on the infamous Jazz Bass drop, when you back off either one of the pickups to about 8, the volume comes back because of the different impedance loading with the added resistance of the circuits. Don't ask me to quote the math or the theory, as this is one instance I don't know it on reactive circuits; this is personal experience since I owned my first Jazz Bass in 1980.

 

[CAMAKAZII]

This is probably an ancient thread but I wanted to share my experience modding my standard P bass (mex) to a 3 pickup’d beast, I used 3 emg MMCS pick ups all in the neck, mid and bridge positions.

To make this work you’ll need to take into consideration a few factors:

you’ll obviously not want to play all at once, as the sound will become far too muddy.

You’ll probably need to run active pickups for the extra output required.

you’ll probably need a lot of extra room in the electrical cavity.

so that being said it was a while ago so I forgot the finer details, however the way I went about this was installing a 5position strat switch and 9v battery box in the rear of the guitar.

Not related but I also run a babics bridge hotshot machine heads and string retainers.

The end result was phenomenal no noise drop and any of the 5 settings and just an amazing sounding bass that effectively sounds like a jazz, standard p or one of those 8 string hyper touchy beasts that you see the artisans playing.

best bass I ever played I will be constructing a new one soon but this time building the body myself out of a nicer Australian wood (as that’s where I live) and installing a jazz neck and perhaps 2 3-way switches to control which pick up is active.