Summoning Elite Troubleshooters

[dwizum]

You're in a tough spot and we are all here to help. The challenge is, without bass-in-hand, it can be really hard to argue or discuss which suggestions are right. I don't think there is going to be 100% consensus on what will solve your problem or even what's worth trying. Often, the best you can do is try things until something works. Sometimes it'll be the first thing you try and sometimes it'll be the 20th. I've been fooling around with basses for long enough to know that, sometimes, the "by the book" thing that works in most cases won't work in every case. By the book should be your first stop, but it may not be your last. EMGs aren't supposed to have bridge grounds and aren't supposed to need shielding, but when you beat your head against the wall trying to get an EMG bass quiet, and finally try adding shielding - and that makes the bass quiet - well, there you go.

 

[Rabidhamster]

It gets challenging when multiple people tell me to try things that contradict each other. That's why I was going to get my list together and try each one, but separately, not simultaneously. I'm trying to show respect to everyone spending time and effort on my problem. If experienced people have differing suggestions on what an inexperienced guy like me should try, it would be awesome if they discussed it.

No problem, follow whichever advice you want.


My advice is correct. Good luck.

 

[Crosscheck67]

No problem, follow whichever advice you want.


My advice is correct. Good luck.

I'm still going to try your advice, so I hope you don't feel like you're being blown off.

 

[spencejm]

I notice you mentioned Coax cable. Are you talking coax with a center conductor and shielding? If so, are both ends of the shielding connected to ground? I’m certainly not a guitar wiring expert but I’ve fixed very unreliable PLC networks by simply disconnecting the coax shielding at one end. With both ends connected it was creating a current loop. Just a thought. Other than that, I would do as suggested and take everything out, test it, and add it back one piece at a time. If you work through this in a logical manner you WILL find the problem.

Joe

 

[Crosscheck67]

I notice you mentioned Coax cable. Are you talking coax with a center conductor and shielding? If so, are both ends of the shielding connected to ground?

Joe

You're thinking of traditional coax, such as RG6, RG59 and such. I had the same thought when EMG said they were sending some to me. These are different, as they have the same connectors as the front panel connectors you find connecting to ATX motherboards. EMG said they are shielded, but I haven't ripped any open to see what's on the inside.

Nonetheless, I've been collecting some test equipment, a new jack, brushing up on multimeter use, making my list of all the suggestions and plan on executing on them this weekend. I've been slammed with helping some users who got hacked, and an emergency vet visit, but should finally get some "me time" soon.

 

[Crosscheck67]

Yeah, I'd do it. It's worked for dwizum and kind of a standard thing when shielding. And the pickup wiring channels, too. Always good to be sure. As I see it, part of troubleshooting, when looking for a problem, is to eliminate the things that aren't the problem. So, if it doesn't work, we're certain what it isn't.

Along a different route...

Normal pots/controls aren't internally grounded to the pot case. As such, the pot bodies are grounded by the cavity shielding or, if no shielding, external wires soldered to the body for interference protection.

EMG stuff is known to be quiet without shielding or external grounding wires. Leads me to think the pot/control bodies are internally grounded to the ground pins of the controls. If you don't mind, would you check that, please. Verifying it one way or another kinda leads to a direction concerning the shielding. Gonna put your new meter to work, man LOL.

With all connectors removed from each control, put one ohmmeter lead on the pot body and the other meter lead on each ground pin. I expect continuity, but just wanna be sure.

Copper or aluminum shielding does pretty much nothing against strong electromagnetic fields, such as those generated by power transformers. It only shields against electrostatic fields by creating a Faraday cage. To shield against electromagnetic fields, you'd have to use a ferromagnetic material such as mild steel or mu metal. Those pickup covers on old Jazz basses did just that.
A passive bass with two singles can be very quiet if both pickups are on and they have opposite magnetic and electric polarity from each other, which will effectively make them into a humbucker. I bet your EMGs are the same polarity, so they can't work together to reduce hum, and I also bet that they're not nearly as immune to hum as EMG says, while you certainly have an environmental problem. Try to turn off anything with a transformer in it anywhere near the bass (say, within a 5-yard radius sphere - including lower and upper floor) while using your AmPlug. The hum should go away.

Well, troubleshooting works like this:
You have a problem.
You remove everything that can be removed from the system.
Now you have a pile of removed things and a bare bones system. You hope that the problem is gone now.
If it is, you reintroduce bit by bit into the system until the problem reappears. Your last step reintroduced the problem. Look at that step.

If removing everything that can be removed did not remove the problem, logic dictates that it's still there.
That's when you need to look hard at the remaining bare bones system and figure a way to troubleshoot there.
Since every part is vital now, you need to swap parts - and it's best practice to swap them for parts that are known to work.

Yes that would theoretically work fine. If you want a test cable/harness though I'd personally include a new jack instead of cutting up that second wire. Just lop the first wire and solder directly to a new jack IMO.

Or just use small alligator clips with the insulator jackets. Make sure you have literally only 1 pickup connected to the jack, no extra grounding anywhere.

I still think you need to pull it all and try passive, but having said that...

I remember a comment from Bill Lawrence about shielding, he said one could use copper or aluminum or anything, it would filter out different frequencies depending on which you use.

So if you think this is environmental, I'd shield the pickup cavities, possibly with both aluminum tape and copper foil. All the shielding has to be connected, and then connect that to the ground of the jack.

Also make sure any computers and other rf stuff are off nearby.

I suspect you've already done this, and also I don't think it'll work because I think it's your pickups that are picking up the environmental noise.

FWIW, I had an alembic, no less, that picked up noise in my studio in a crappy place where I used to live. Alembic tried to help, but it turned out it was just bs where I lived. When I turned off my stereo tuner, it went away.

Without knowing the real specific details of a certain situation, that's probably hard to answer, since it depends on the type/intensity of the environmental noise and where in your wiring it's being picked up, among other factors. I've had basses where shielding the pickup cavities cured an annoying constant hum - even though the pickups themselves were already internally shielded (as EMGs in theory are). On paper, that doesn't make much sense, but it is what it is. And of course, I've had plenty of other basses where it made no difference - either the bass was already dead silent without it, or adding it didn't change anything.

I've lost track of the thread, but if I were in your shoes, and the cavities were not shielded (and hadn't been, through this whole experiment), I would at least try it. It's 15 minutes and a couple cents in copper tape. Not much to lose.

All,

I've done a bunch of testing.

- I grabbed a nice auto-sensing multimeter (patterned after a Fluke, but a hell of a lot less) and tested each pot case to their respective GND pins. All had continuity and theoretically, proper internal grounding.

- I made a custom cable that goes from the pickup direct to the leads on the jack. To indulge everyone, I tried this with and without being grounded to the control cavity shielding (this shielding remains for now, as I've already ripped it out for testing previous to this thread, so it's been shielded and naked twice). I disconnected the batteries, Vol, Blend and BTC. So we are talking an authentic, passive, direct connection from pickup to jack. I tried two different jacks as well. For grins, I even removed the black lead (same as GND), and of course that produced a strong ground noise with no pickup signal.

Using my Vox Amplug and headphones, the hum remained in all scenarios, with the telltale polar opposite quiet spots. Two questions for the two different schools of thought:

1) Team No-Shielding: what do you make of this? It's doubtful that EMG sold me two defective pickups direct from their company. What should be my next step?

2) Team Shielding: given the results thus far, do you still find it worth shielding the pickup cavities, battery box cavity, grounding those along with the control cavity, etc? What should be my next step?

I'll still proceed with suggestions. But in this moment, I'm leaning towards plastering my wall with heavy duty aluminum foil and getting an Electroharmonix Hum Debugger. I'm half-way considering other pickups, but I have no idea who makes a high quality warm jazz pickup. I don't like Bartolini.

Thanks again for all your input

 

[dwizum]

It's been a while and I've lost track. Have you tried in other locations and/or with a other amp?

It's possible that the issue is in the amplug.

 

[dwizum]

I'm going to repeat what I said above. If I were in your shoes I would try grounding the shielding you have and adding grounded shielding to the pickup cavities. I know EMGs are not supposed to need shielding or a grounded bridge, but you have nothing to lose by trying, and I've worked on several basses with EMGs and other brands of "already noise free, needs no shielding" pickups where adding shielding to the cavities eliminated the noise.

 

[Rabidhamster]

Lol you disconnected the battery? Yeah, that’s not gonna work.

 

[Crosscheck67]

Lol you disconnected the battery? Yeah, that’s not gonna work.

...and yet it did. No battery, no pots, direct from the pickup to the jack, and the strings produced notes. Did I misunderstand what you meant?

 

[Crosscheck67]

It's been a while and I've lost track. Have you tried in other locations and/or with a other amp?

It's possible that the issue is in the amplug.

I think because of the lapse, I owe everyone a recap:

The problem is hum from EMI affecting my active EMG J5 set with the BTC System. It manifests in all scenarios at home regardless of signal chain and power supply. Furman PL-Plus DMC, power conditioner, pedalboard with Source Audio effects, Audient iD44 USB interface, EBS Magni 500 2x10 combo amp, or just using a Vox Amplug with headphones.

We know we're dealing with EMI because one, it happens at some locations - especially my home - and not others, and two, I killed the power to my entire home, plugged my Vox Amplug into my bass along with headphones, and walked from back to front towards the power lines out front. The hum grew worse the closer I got to the power lines.

I have sent all my equipment to EMG and their head engineer tested everything on their bench. It checked out fine there, but they admitted they are in a sparsely populated area of northern Cali. They also had me test different internal signal chains, bridge and jack grounding, then finally ripping out the shielding and so on.

The posts people have provided include two schools of thought. One is testing with no shielding or grounding as EMG is internally grounded and advises against it, and two, shielding and grounding all cavities. Before I execute on the latter, I hope to exhaust all testing with the former. The common thought was to strip things down to the bare minimum and start adding things back one by one.

My delay in executing on the latest batch of tests was due to several factors, but I did them and detailed results a couple posts above.

Hope this helps.

 

[Rabidhamster]

...and yet it did. No battery, no pots, direct from the pickup to the jack, and the strings produced notes. Did I misunderstand what you meant?

So you’re telling me your active EMG J5 pickups are working without any power whatsoever?
Because they do not work without power. So I’ll give you the benefit of the doubt that you aren’t trolling us but really think you removed the power and accidentally removed something else instead?

I won’t repeat my original advice but I hope you’ll go back and read it very carefully and follow it. The problem with taking part of multiple pieces of advice and interspersing it with what you think you already did before asking for troubleshooting help is it usually just wastes your time unless your goal is just to have a long thread. Good luck!

 

[Crosscheck67]

So you’re telling me your active EMG J5 pickups are working without any power whatsoever?
Because they do not work without power. So I’ll give you the benefit of the doubt that you aren’t trolling us but really think you removed the power and accidentally removed something else instead?

I won’t repeat my original advice but I hope you’ll go back and read it very carefully and follow it. The problem with taking part of multiple pieces of advice and interspersing it with what you think you already did before asking for troubleshooting help is it usually just wastes your time unless your goal is just to have a long thread. Good luck!

Me troll you. That's rich. I've read your instructions at least 5 times, I've admitted I'm new to guitar and bass electronics, so I don't know what else you want. No I do not want a long thread, no I am not trolling anyone. I want this to be over. I'm not going to waste the time of people trying to help me. So I am telling you, as plainly as I can:

There is only the positive and negative wires - white and black - going from the pickup to the jack - nothing in-between - and again, I tried two different jacks. The power - red - is not connected to anything. I listened first through my Amplug, then I played through my Audient interface. The hum was there, and the notes could clearly be heard, albeit quieter than with the normal active wiring.

I'm as surprised as you are. My luthier told me EMGs have active electronics not only in the BTC system, but also in the pickups themselves and therefore would require power. However, reading your instructions there is no mention of battery that I can find, and in fact you said "you don't need to remove it from the instrument but it needs to not be connected to the active wiring harness". If that somehow also means to leave it connected to power, it's unrealistic to expect a noob to figure that out. So I was literally trying to follow your specific instructions.

Did EMG change their technology? Are these pickups defective? Did the great lord Odin reach down with his sword and alter physics in my bass? Hell if I know.

 

[el murdoque]

Get a set of Aguilar pickups and be done with it.

 

[Rabidhamster]

Me troll you. That's rich. I've read your instructions at least 5 times, I've admitted I'm new to guitar and bass electronics, so I don't know what else you want. No I do not want a long thread, no I am not trolling anyone. I want this to be over. I'm not going to waste the time of people trying to help me. So I am telling you, as plainly as I can:

There is only the positive and negative wires - white and black - going from the pickup to the jack - nothing in-between - and again, I tried two different jacks. The power - red - is not connected to anything. I listened first through my Amplug, then I played through my Audient interface. The hum was there, and the notes could clearly be heard, albeit quieter than with the normal active wiring.

I'm as surprised as you are. My luthier told me EMGs have active electronics not only in the BTC system, but also in the pickups themselves and therefore would require power. However, reading your instructions there is no mention of battery that I can find, and in fact you said "you don't need to remove it from the instrument but it needs to not be connected to the active wiring harness". If that somehow also means to leave it connected to power, it's unrealistic to expect a noob to figure that out. So I was literally trying to follow your specific instructions.

Did EMG change their technology? Are these pickups defective? Did the great lord Odin reach down with his sword and alter physics in my bass? Hell if I know.

. Please quote my post and highlight the sentence that made you think I told you not to connect power. Remember the very first sentence take a pickup out and hardwire it to power and the output Jack, and you didn’t want to do it?
You haven’t followed my instructions, you specifically described not following them, and the pickups DO NOT work without power. I’m not surprised, I’m telling you it is not happening. You’re either confused or lying - there is no other option, because they don’t work without power.

I highly recommend you stop immediately and take the bass to a professional to fix it for you. Good luck!

 

[bdplaid]

Figure out the things that have remained constant throughout all this and change them.
I think you've jumped through flaming hoops trying to make those pickups work, and a change to passive is at least worth a try.

 

[Crosscheck67]

Figure out the things that have remained constant throughout all this and change them.
I think you've jumped through flaming hoops trying to make those pickups work, and a change to passive is at least worth a try.

That's the frustrating part. I've changed so many things that the only two options from here are to try a different pickup, or go all out with shielding and grounding everything. Before that, I was just waiting for any remaining tests from team "No Shielding".

 

[Crosscheck67]

. Please quote my post and highlight the sentence that made you think I told you not to connect power. Remember the very first sentence take a pickup out and hardwire it to power and the output Jack, and you didn’t want to do it?
You haven’t followed my instructions, you specifically described not following them, and the pickups DO NOT work without power. I’m not surprised, I’m telling you it is not happening. You’re either confused or lying - there is no other option, because they don’t work without power.

I highly recommend you stop immediately and take the bass to a professional to fix it for you. Good luck!

I already took it to two professionals. That's how I landed here in the first place. Each has business partners, all who have been doing this for decades, are in high demand and have proven track records. One says there is nothing more he can offer, the other recommends the Hum Debugger pedal. They both concur it's something in the EMGs picking up EMI.

As for your quote, I did go back and see the power part. I misunderstood because of your comment "it needs to not be connected to the active wiring harness". I don't know what you meant by that, given that you also wanted it to be connected to power. In my limited understanding of this, "active" and "power" are synonymous.

But what makes that interesting was the result of my ignorance. As I misunderstood you, and wired the pickup directly to the jack, with no batteries present and no wires connecting the active circuitry (red), and only connecting the positive and negative, or tip and ring, or positive and neutral, black and white...whatever the proper term is...I indeed produced passive output, despite your conviction. I am not confusing it with string resonance through the wood. I can record and play back notes. I am not confused, I am not imagining this, and please drop the lying and trolling hypotheses. Two wires. On the proper terminals. Nothing else.

I know this because after your last post, I did connect the red wire from the pickup to the battery box and the black from the battery box to the R lead on the jack and sure enough, got output at a much higher amplitude. The hum and signal output remained in both scenarios, obviously both louder with power connected.

 

[Rabidhamster]

I already took it to two professionals. That's how I landed here in the first place. Each has business partners, all who have been doing this for decades, are in high demand and have proven track records. One says there is nothing more he can offer, the other recommends the Hum Debugger pedal. They both concur it's something in the EMGs picking up EMI.

As for your quote, I did go back and see the power part. I misunderstood because of your comment "it needs to not be connected to the active wiring harness". I don't know what you meant by that, given that you also wanted it to be connected to power. In my limited understanding of this, "active" and "power" are synonymous.

But what makes that interesting was the result of my ignorance. As I misunderstood you, and wired the pickup directly to the jack, with no batteries present and no wires connecting the active circuitry (red), and only connecting the positive and negative, or tip and ring, or positive and neutral, black and white...whatever the proper term is...I indeed produced passive output, despite your conviction. I am not confusing it with string resonance through the wood. I can record and play back notes. I am not confused, I am not imagining this, and please drop the lying and trolling hypotheses. Two wires. On the proper terminals. Nothing else.

I know this because after your last post, I did connect the red wire from the pickup to the battery box and the black from the battery box to the R lead on the jack and sure enough, got output at a much higher amplitude. The hum and signal output remained in both scenarios, obviously both louder with power connected.

I thought I'd give one more shot and describe the test process visually for you. Take 1 pickup out of the bass and set it on your desk and test it like this. 1 at a time.

Sure if you pop enough gain and volume on any EMG without batteries you'll eventually hear notes but its not exactly what I'd consider functional. Actually if you easily heard notes on your Amplug with no batteries in the EMG then I bet the Amplug is probably contributing a lot of the noise you're hearing because that takes quite a lot of gain. I couldn't use one as a noise reference, they're somewhat noisy alone. It can get really frustrating when you have multiple sources of noise at the same time.

Make sure you're still using known good amplification and cable.

 

[bdplaid]

You've wasted an enormous amount of effort trying to salvage the pickups.