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Do I need a bridge ground for an active system?
- Thread starter Gojiberry22
- Start date
I do not hold an electricians license if that is what you are really asking.
And as such, I am only qualified to comment on grounding to the same extent as anyone else here who does not hold an electricians license.
I am an electronics technician of 45 years.
But I suspect there are those who will argue; that counts for nothing.
And for the most part that would be a valid argument which I would be willing to accept.
The like argument could also be made towards the expertise of an electrician on the subject of instrument grounding.
Like many areas of electronics, there are many disciplines with which an electrician might specialize.
And also like a person who specializes in one area of electronics, he may be lacking in other areas.
And so, may be the case for an electrician. How many people who wire houses for a living are experts at wiring high tension distribution systems?
I hold two of the highest licenses issued by the federal government that a person in my field might hold.
Does that make me an expert in all facets of electronics? Heck no it doesn't.
I don't know if someone who holds an electricians license is automatically considered to be an expert in all facets of electricity either, but I suspect not.
I presume, since you asked if I'm an electrician, that you yourself do hold an electricians license.
Would I be correct in that assumption?
And the reason I ask this is, if you are a licensed electrician in the US, I presume that you also have access to the NEC?
I have attempted to look on-line for the code regarding the grounding of electric guitars and amplifiers.
I have found little or nothing so far in my search mainly because finding the code on-line appears to be something that one must purchase.
This then takes me to my question which I will ask of you as I presume you have the license and access to the electrical codes.
If, as you state, having a grounded bridge is a safety risk, due to the possibility of other faulty equipment, why do pretty much all electric guitars come from the manufacturer with grounded bridges? How can it be that everyone is allowed to sell something that poses such a risk?
Is there something in the electrical code that states that a manufacturer must ground all metal parts of an instrument, intended for sale, that can come into contact with a person? Or likewise, are there any recommendation to do so by Underwriters Laboratory or other standards committees?
I am very curious to know the answer to these questions from someone who is an authority on the subject.
I understand that after an instrument has been sold and if the owner so chooses to modify the instrument, that there would no longer be any liability by the manufacturer. It's the owners choice if he decides to modify it and in doing so that modification creates a risk. But I am really interested in your opinion about the requirements of manufacturers in the US and what, if any electrical codes apply to the grounding of instruments.
I have tried to explain, why I feel all of the metal parts of a bass should be grounded and what can happen if you don't ground them.
I have yet to see anyone explain to me why a bridge SHOULD NOT (NOT doesn't need to be - I know that answer) but should not be grounded.
Other than your argument that it is a risk if you touch some other piece of faulty equipment. Which by the way, I also understand how that can happen.
But no one has come forward to explain how an active pickup can malfunction, or otherwise be affected by having a ground wire running from the ground on the instrument jack to the bridge. I wish someone would tell me what goes wrong and why. Or if some has grounded the bridge and what happened, if anything.
So you can see that I am trying to understand the other side of this argument, but other than your explanation, which by the way I consider a valid one, even though I disagree with how to prevent the outcome. I want you to recognize that I understand where you are coming from on that point.
As to the other arguments, no one has brought forth anything other than the parroting of something they read on line or in an instruction manual.
And we all know instruction manuals are 100% non-fallible in their attempt to convey technical information to, often times, non-technical people.
So help me understand all of this on a technical level, please. I think I have the chops to keep up. And if I don't I hope you don't mind me asking additional questions.
Thanks for your patience.
I will pipe up and say,
I am a registered electrician,
and a certified telecommunications technician,
i have a diploma in electronics and radio,
and various other bits of paper I have accumulated in my 40 year work career,
that indicate I might know a little bit.
Two things I can state (IMO/IME)
1: grounding the bridge will improve noise rejection.
2: grounding the bridge and strings does not increase safety from electric shock.
3: do not borrow a power lead from your singer, who after the fact you got electrocuted between holding your grounded bass strings and lips on the mic,
tells you that he rewired the broken plug (and he has no clue about electricity).
The best device for personal safety (regardless of if the bridge is grounded or not - your personal choice) is plug in Earth Leakage Circuit Breaker (ELCB or RCD or GFCI).
I don't think an active pickup really cares if the bridge is grounded or not, it makes no difference if it is active or passive,
so long as your grounding is bonded at one common point and radiates outward in a star topography.
my 2c
I am a registered electrician,
and a certified telecommunications technician,
i have a diploma in electronics and radio,
and various other bits of paper I have accumulated in my 40 year work career,
that indicate I might know a little bit.
Two things I can state (IMO/IME)
1: grounding the bridge will improve noise rejection.
2: grounding the bridge and strings does not increase safety from electric shock.
3: do not borrow a power lead from your singer, who after the fact you got electrocuted between holding your grounded bass strings and lips on the mic,
tells you that he rewired the broken plug (and he has no clue about electricity).
The best device for personal safety (regardless of if the bridge is grounded or not - your personal choice) is plug in Earth Leakage Circuit Breaker (ELCB or RCD or GFCI).
I don't think an active pickup really cares if the bridge is grounded or not, it makes no difference if it is active or passive,
so long as your grounding is bonded at one common point and radiates outward in a star topography.
my 2c
Thank you for presenting a balanced and thoughtful response to the subject.
I love # 3 and # 4 is is a -must do- for any gigging artist.
"Don't need one" and should not use one, are two very different statements.
I know exactly why you don't NEED one.
(More thoughts on that later.)
At the point when you wrote this those are ALL correct statements IMHO.
There are those who will have had, in subsequent posts, argue that it is wrong.
I don't disagree with those people on principle, but I do disagree with the logic they used to arrive at their conclusion.
Now if you agree that it is not wrong to ground a bridge. I agree with you. FWIW.
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@Old Garage-Bander I'd say that with the credentials you've cited you could get away with calling yourself an electrician.
You surely know that there are plenty of ways to improperly install a grounding conductor. It could be the wrong size, terminated incorrectly, not adequately isolated from current carrying conductors, equipment could be compromised by makeshift repairs...etc, which all could provide an inadequate ground or worse yet, introduce current to the grounding conductor.
I can't speak to your specific question about what could go wrong with your active bass if the bridge is grounded but I trust the manufacturer, other experts here and mainly the many testimonials of those successfully using instruments without a bridge ground enough to know that it's not necessary.
You surely know that there are plenty of ways to improperly install a grounding conductor. It could be the wrong size, terminated incorrectly, not adequately isolated from current carrying conductors, equipment could be compromised by makeshift repairs...etc, which all could provide an inadequate ground or worse yet, introduce current to the grounding conductor.
I can't speak to your specific question about what could go wrong with your active bass if the bridge is grounded but I trust the manufacturer, other experts here and mainly the many testimonials of those successfully using instruments without a bridge ground enough to know that it's not necessary.
One of the very finest builders in the world insists on grounding EMG pickups when used with his active circuits, which are accepted amongst the top working players and sound engineers in live and in the studios today. I've had one of his basses with EMG pickups, an active circuit, AND a ground wire to bridge for nearly three decades, as have many other players. Nothing unusual to report over thousands of gigs and recording sessions, from me or anyone else. There is no issue attached to grounding EMG pickups while using an active system.
This rationale of proven real-world effectiveness not be good enough for you - it rarely is on this forum - but it is good enough for many others.
Just as a counterpoint to your point.
I have tapes on my bass.
The metal under the tape is attached to the little brass loop at the bridge end of the string.
The little brass loop is held tight up against the metal bridge.
If the bridge is grounded, so are the strings.
While you are correct that you cannot ground yourself by touching the strings, you can by touching the bridge.
But having noise that goes away while touching the strings, or the bridge, is something that should really be fixed without having to touch anything.
From the EMG site:
'"When installing EMG Active Pickups, DO NOT connect the bridge ground wire.
This wire is usually soldered to a Volume or Tone control casing and goes to the bridge.
This wire grounds the strings and uses them and your body as a shield against hum and buzz. It also creates a shock hazard.
EMG Pickups are shielded internally and DO NOT require string grounding. This greatly reduces the possibility of reverse polarity shock from microphones and other equipment."
Invalid Link Removed
'"When installing EMG Active Pickups, DO NOT connect the bridge ground wire.
This wire is usually soldered to a Volume or Tone control casing and goes to the bridge.
This wire grounds the strings and uses them and your body as a shield against hum and buzz. It also creates a shock hazard.
EMG Pickups are shielded internally and DO NOT require string grounding. This greatly reduces the possibility of reverse polarity shock from microphones and other equipment."
Invalid Link Removed
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And in wrapping up, it appears that no one is going to say...
"It doesn't matter"...
(Of course it matter, but that's not at all relevant to my point...)
"It doesn't matter"...
(Of course it matter, but that's not at all relevant to my point...)
You are too kind sir: Really!
I would no more dishonor a licensed electrician by trying to get away with calling myself one, than I would in calling myself an engineer even though others refer to me as one at work.
I work in our engineering department and my title has "engineer" in it, which is more tradition than anything else in my field.
I always make certain that others know I am a technician by trade, education and experience. If I must use it for myself, I use a little e.
The Double E's (I didn't miss that in your screen name) of the world all worked way harder and know a lot more than I and have earned the title Engineer (big E).
My hat's off to you folks.
Well ive gone ahead and installed everything. Without a bridge ground that is. And its dead silent, its fair to say a bridge ground was not needed at all.
Now i don't know if this is the case for all active systems but for emg I can personally confirm that a bridge ground is not needed.
Now i don't know if this is the case for all active systems but for emg I can personally confirm that a bridge ground is not needed.
Given the way EMG does everything that it seems one can do in noise suppression technics, this is no surprise.
My understanding of the EMG systems, especially the modular, pre-wired ones are:
1. That the actual electro part, the windings, which by themselves are not active, are lower Impedance than that usually found in passives. This due to fewer windings, which results in lower output that is later made up by the following active electronics.
2. The on-board active electronics are as close to the windings as physically possible.
3. I believe the windings to electronics are balanced, though being that short of a distance probably makes little to no difference in being balanced or unbalanced.
4. The entire assembly, pickups and active electronics is shielded.
5. Even though the outputs are unbalanced, the electronics maintains a lower impedance while probably also maintaining a higher level for the signal at the output Jack.
In essence, they do all the things that one should do to fight noise from getting in from the outside.
Gojiberry22, it would be interesting for you to experiment by temporarily attaching a wire from your bridge to some metal on the control panel if you have one, or otherwise to the metal, outside shell of the instrument cable Jack. These points should be grounded by the shields connection to the amp. It's just to see if you notice any discernible increase in noise.
As far as the safety grounding issue is involved, that seems to be a split decision.
Aside from the noise consideration, some advocate for not grounding the bridge.
The reasons given, when there were any reasons given, involved a shock hazard with grounded bridge/strings.
The hazard comes from touching grounded strings or bridge AND touching another piece of equipment that due to it's own internal fault has put a voltage on the metal part which itself has no safety ground.
Not grounding the bridge may help avoid a shock hazard when also coming in contact with other non-grounded metal on other equipment.
The argument for grounding the bridge, aside from noise considerations, is to act as a safety ground should your own amp develop an internal fault that places a voltage on metal that is not grounded. So the question is, do I ground to protect myself against the equipment I'm touching or do I not ground to protect myself from unknown conditions of other equipment? And do you know for certain that you are not a path for electricity even though not grounded? "Ask yourself, do you feel lucky punk? Well do ya?"
While I will admit that the chances of one finding stray voltages on other faulty equipment at some dicey venue are greater than the chances of your personal, modern amplifier developing an internal fault. The real issue is that we should all understand the risks and take precautions to not get into a shock hazard situation in the first place.
Also keep in mind that while your bridge and strings may not be grounded, your control plate if you have one, and certainly the metal shell of the instrument cable are grounded. Even if you have a plastic shell there is the sleeve if the Jack when not plugged into your instrument. All of this assumes your amp is connected to to a grounded outlet, which brings us back to the dicey venue.
Gojiberry22. I'm so glad to hear you finished you project and that it all worked out well for you. Check back with us after you've had done play time on you new bass. And don't forget the pics!
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That seems to be the Santa Rosa way of fighting noise
(Both EMG and Alembic are in SR )In my Metallica tribute band I always use a wireless, never played a passive through that rig though...
Will a bridge ground wire make any difference when using a wireless system with a electronics that require the bridge ground under "normal" conditions?
(I would never clip the ground wire, just trying to understand the concept)
Well being wireless certainly renders the whole safety ground argument moot.That seems to be the Santa Rosa way of fighting noise
In my Metallica tribute band I always use a wireless, never played a passive through that rig though...
Will a bridge ground wire make any difference when using a wireless system with a electronics that require the bridge ground under "normal" conditions?
(I would never clip the ground wire, just trying to understand the concept)
I wouldn't think the bridge ground would make much difference in a wireless. Especially with you EMG setup.
Wireless with passives, restricts the length of anything that acts like a buzz/hum "antenna", to what ever wiring is in your bass much like the active electronics isolates that "antenna" to short amounts of wire. That includes the cable to the wireless transmitter whifh will only be two or three feet. Certainly an improvement over the 20 ft cable to your pedal board and another 20 ft back to the amp.
If everything in the bass is grounded in a star pattern as it should be, adding or subtracting one more "point" of a star really shouldn't matter. I would think that shielding the bass cavity for a wireless might be more critical, especially with single coil pickups. But you've avoided all that monkeying around.
EMG doesn't supply any solder-less bridge grounding wire for their active pickup systems .. this is not the case, for instance, of the GZR pickup, which is passive, and supplied with a wire having a crimpable termination on the bridge side and a solder-less connector on the opposite one.
Hence, I assume that bridge grounding with EMG active pickup system is not necessary in terms of shielding the system from interferences due to the circulation of electric currents from and towards the bridge.
I'm switching the pickup of my Classic '50s P Bass for an EMG PAX tomorrow .. I'll see how it goes ...
Active pickups do not have to be confused with onboard electronics for passive pickups signal pre-amplification.
Different designs and different aims.
The new AlNiCo V P-bass active pickup from EMG (PAX) is probably one the best sounding P-bass pickup I've ever had a chance to play and listen to ... very, very clear and rich in all frequency ranges and, moreover, dead quiet .. really a nice discovery .. you just need a little space for the battery ... people who liked the GZR passive pickup from EMG would be amazed by how clearer sounding the PAX is in comparison ... unfortunately it seems that there's a general aversion regarding active pickups (not only on TalkBass), which, in my opinion, is not really justified .. the PAX I briefly installed on a crappy Hondo II P-bass clone sounded equal if not better than the vast majority of the so-called vintage reproduction pickups, including those of highly revered brands such as Lindy Fralin, Seymour Duncan etc.
Although the look of it is not exactly vintage, i'm going to install it on a Classic '50s P-bass of mine !
