Got damn buzz! Please help!!

[Ric5]

I will kill that damned mythical ground loop yet!!!

 

[michaelandrew]

Humbuckers only get rid of the hum part. The buzzing stuff is electrical field noise. There's probably something getting unbalanced when the blend control is at the extreme positions. I've never heard of that happening, but I'm not familiar with their circuit (I'm assuming it has a preamp?)

I've seen some issues with Yamaha electronics over the years.

I agree about Yamaha electronics, but I've replaced them. With the original Yamaha pre-amp the noise was so bad that the balance control had to be centered always. I've now replaced the Yamaha pre-amp with an Audere (highly recommended) and it's MUCH better, but still noticeable at times.

I like the Yamaha pick-ups otherwise and they'd be difficult to replace because of their odd size, so I can live with the noise. I was just curious whether there might be something inherent in the pick-up design - wish I could see inside.

Thanks.

 

[-=DanAtkinson=-]

If this were true, a single point ground would not be necessary.
I would never make this assumption in a low noise circuit
design. This is the fundamental difference between what you
believe and what I believe.

Unless you have a noiseless, currentless environment or unless
you are using zero ohm superconductors to carry your signals,
no two ground points are ever at the same potential.
A quick Google search shows that I am in good company with
this belief.

From: https://passlabs.com/articles/ground-loops
"The key points to understand are that there is no such thing
as a perfect ground and that no two ground points within any
system are ever exactly equipotential to one another."

From: Link Removed
"When carrying current, no two points on the conductor are
at the same potential."

From: Invalid Link Removed
"No two ground points have exactly the same potential."

This one is from a physics department (what do they know?):
Link Removed
"No two ground points are at the same zero potential."

From: http://www.qsl.net/kd6pag/usenet/Grounding.html
"No two points on Earth have the same potential
when currents are flowing between them."

From an electronic design magazine:
[Invalid or Expired Link Removed]
"In practice, however, no two points on a circuit's ground
plane are exactly at the same potential, and they generally
exhibit a nonzero impedance between them."

Link Removed
"NO TWO GROUNDS HAVE THE SAME POTENTIAL ENERGY
UNLESS CONNECTED WITH A RESISTANCELESS FLOW PATH "

The fact that you insist on randomly hitting the Return key, rather than allowing the text to autowrap, is deeply disturbing to me.

 

[warnergt]

I need to juxtapose these two positions for greater contrast.

dmusic148 says:
"...all of that noise will follow the path of least resistance, which is to ground. It all ends up at the third lug of your power cord... Down the drain it goes... It goes to ground."

Bill Whitlock, Engineer, President of Jensen Transformers, holder of two patents, active member of the Audio Engineering Society and the Institute of Electrical and Electronic Engineers says,
"Many indulge in wishful thinking that noise currents can somehow be skillfully directed to an earth ground, where they will disappear forever!"

That is pure gold! Bill Whitlock must be psychic. It is as if he knew you were going to say that!

 

[michaelandrew]

If this were true, a single point ground would not be necessary.
I would never make this assumption in a low noise circuit
design. This is the fundamental difference between what you
believe and what I believe.

Unless you have a noiseless, currentless environment or unless
you are using zero ohm superconductors to carry your signals,
no two ground points are ever at the same potential.
A quick Google search shows that I am in good company with
this belief.

From: https://passlabs.com/articles/ground-loops
"The key points to understand are that there is no such thing
as a perfect ground and that no two ground points within any
system are ever exactly equipotential to one another."

From: Link Removed
"When carrying current, no two points on the conductor are
at the same potential."

From: Invalid Link Removed
"No two ground points have exactly the same potential."

This one is from a physics department (what do they know?):
Link Removed
"No two ground points are at the same zero potential."

From: http://www.qsl.net/kd6pag/usenet/Grounding.html
"No two points on Earth have the same potential
when currents are flowing between them."

From an electronic design magazine:
[Invalid or Expired Link Removed]
"In practice, however, no two points on a circuit's ground
plane are exactly at the same potential, and they generally
exhibit a nonzero impedance between them."

Link Removed
"NO TWO GROUNDS HAVE THE SAME POTENTIAL ENERGY
UNLESS CONNECTED WITH A RESISTANCELESS FLOW PATH "

All good stuff and no disagreement - "there is no such thing as a perfect ground" - which is why I'd suggest measuring the resistance between the the output jack sleeve ground and various other points in the circuitry (bridge ground, cavity grounds, pick-up grounds etc.). If it's less than a few milliOhms, it's nothing to worry about, in practice, for bass guitar wiring (it's also a good check for ground faults).

 

[warnergt]

Hey SGD Lutherie, regarding those conflicting statements by
dmusic148 and Bill Whitlock, whom do you agree with?

I'd like to know if you guys who disagree with me actually
agree with each other.

 

[bumperbass]

We agree with one another to disagree with you.

 

[wvbass]

I am an EE as well as a CpE. Not sure that is is relevant, but we seem to need credentials to post in this thread, so there you go.

There are some holes in logic here - so big that they don't deserve to be enumerated. So, I will instead say this: technically, you are correct. However, the actual measurements by which you could use to prove you are correct would be so insignificant as to be dismissable for all practical purposes.

Further, you could ground your pickups to the bridge. That would be some inconvenient wiring, but it would be fine. I have grounded pickups to shielding in the pickup cavity before with no ill effects. Once you connect the shielding, or the bridge,to the output jack, they are all connected to, or part of, the ground plane. Yes, there will be a slight difference in potential at different points on the ground plane due to resistance of the plane itself, but a good multimeter will read this as 0.000 ohms.

This is the same measurement you will get when you measure resistance from your star ground point to the other end of a wire connected to the star point.

If you get any other reading, you probably have a bad solder joint somewhere.

 

[wvbass]

Hey SGD Lutherie, regarding those conflicting statements by
dmusic148 and Bill Whitlock, whom do you agree with?

I'd like to know if you guys who disagree with me actually
agree with each other.

The statements are not in conflict with each other. You are correct that they appear to be in conflict with each other, but neither statement was made in a vacuum. Each statement was made in a different context - you have to read the other sentences, too.

This reminds me a lot of politics and the manipulation of sound bytes and presenting statements out of context in an effort to give them meaning that was not intended...you didn't build that!

Edit: I miss Bill.

 

[warnergt]

All good stuff and no disagreement - "there is no such thing as a perfect ground" - which is why I'd suggest measuring the resistance between the the output jack sleeve ground and various other points in the circuitry (bridge ground, cavity grounds, pick-up grounds etc.). If it's less than a few milliOhms, it's nothing to worry about, in practice, for bass guitar wiring (it's also a good check for ground faults).

I can't disagree with this. You're saying there is a difference
but it is probably very small. True.

But here's the thing: that small difference may be meaningless
in most situations. You may think you have the quietest bass
(or guitar) on the planet. But one day, you're playing in a
harsh noise environment. Perhaps a small venue has you
pressed up against the Coors Lite sign or it's near a radio
station or near a powerful transformer or some other
significant source of noise. You're gonna hear it. The kicker
is that you could have used good design practices (do I need
to say it? -- like a single point ground) to reduce and possibly
avoid these contributions to noise.

If you're involved with electronics, you know that noise is
evil. It can be maddening to deal with. EMI, magnetic fields,
ground loops -- you fight it with every tool you have: grounding,
shielding and, of course, single point grounds. You ignore a
tool at your peril. In my book, to purposely avoid one of the
tools is poor engineering.

 

[warnergt]

The statements are not in conflict with each other. You are correct that they appear to be in conflict with each other, but neither statement was made in a vacuum. Each statement was made in a different context - you have to read the other sentences, too.

I read the full context of both. They are in direct conflict.

 

[warnergt]

I am an EE as well as a CpE. Not sure that is is relevant, but we seem to need credentials to post in this thread, so there you go.

Credentials are not required.
Out of curiosity, what is a CpE?

 

[WoodyG3]

I am enjoying this thread simply because I am learning some things, so if you guys don't mind, can you explain how the whole grounding scheme changes, or if it changes, when you add a preamp? Is there still just one ground point at the output jack? Is the preamp circuit itself completely separate from the rest of the bass wiring?

Thanks!

 

[michaelandrew]

I can't disagree with this. You're saying there is a difference
but it is probably very small. True.

But here's the thing: that small difference may be meaningless
in most situations. You may think you have the quietest bass
(or guitar) on the planet. But one day, you're playing in a
harsh noise environment. Perhaps a small venue has you
pressed up against the Coors Lite sign or it's near a radio
station or near a powerful transformer or some other
significant source of noise. You're gonna hear it. The kicker
is that you could have used good design practices (do I need
to say it? -- like a single point ground) to reduce and possibly
avoid these contributions to noise.

If you're involved with electronics, you know that noise is
evil. It can be maddening to deal with. EMI, magnetic fields,
ground loops -- you fight it with every tool you have: grounding,
shielding and, of course, single point grounds. You ignore a
tool at your peril. In my book, to purposely avoid one of the
tools is poor engineering.

Yes, that's what I'm saying and, again, no disagreement; star grounding is certainly good practice. But if you measure the DC resistance between two ground points and it comes out 0.000 Ohms on a DVM, it isn't significant for bass guitar wiring; it won't be zero, but close enough for rock 'n' roll.

I live in a terrible electrical noise environment - on an approach path to a major airport and close to several local radio station transmitters. All that crap gets on the house power and phone wiring and into my bass pick-ups. Star grounding - which I do use, but for convenience, not to remove ground loops - won't help that situation.

You're cetainly correct when you say it's maddening.

 

[SGD Lutherie]

If this were true, a single point ground would not be necessary.
I would never make this assumption in a low noise circuit
design. This is the fundamental difference between what you
believe and what I believe. .......

It has nothing to do with belief. That's the problem. You are treating this like a belief system. You are imagining problems where none exist. Yet, you wont even try and prove that this imaginary noise current is flowing in your bass grounds.

None of what you linked to has anything at all to do with bass wiring! Nothing!

Why don't you understand this?

And you talk about being in a noisy bar with a neon sign and all... star grounding in your bass wont get rid of that noise!

My basses are dead quiet in noisy bars, and I play in a lot of them. But, my amp and the PA hum in the same bars. That kind of negates the good shielding and wiring in my basses. So what are you going to do?

And why are you hitting your return key?

You are being obtuse.

 

[JoeWPgh]

I'm going to say something really stupid sounding. Have you tried a different cable? A poorly shielded cable will be just as bad at rejecting noise as a poorly shielded instrument. And chances are it will actually be much worse, given the length of it's signal path. Don't ask how I came to understand this

 

[michaelandrew]

I am enjoying this thread simply because I am learning some things, so if you guys don't mind, can you explain how the whole grounding scheme changes, or if it changes, when you add a preamp? Is there still just one ground point at the output jack? Is the preamp circuit itself completely separate from the rest of the bass wiring?

Thanks!

The pre-amp ground will be the same as everything else on the bass that's grounded. Strings, bridge, pick-ups, cavity shields, pots, pre-amp ground (if there is one), cover plates, etc. - all are connected to the output jack sleeve ground in some way.

The output jack ground is then connected to the shield ground braid on the coaxial guitar cable, back through to the power amp and eventually to the ground pin ("third prong") on the amp's power cord.

Grounds are never perfect, however, and The "ground loop"... umm... discussion concerns that, and under what conditions it might cause trouble. Normally, it doesn't (IMO).

There's some good, not-too-technical, information in the FAQs on the Audere web site that might help.

 

[BlueTalon]

Whether or not star grounding works is not decided by a small democratic vote. Just because I'm surrounded by a few flat earthers here doesn't make it wrong. There are many, many guitar builders who insist it works. If you go over to the gearpage.net where guitarists hang out, the overwhelming consensus is that it works.

I am completely on the sideline in this debate/argument, but this was just too funny to pass up.

So a small democratic vote doesn't decide whether or not star grounding works, but a big democratic vote does?

 

[fenderphil]

couldnt a bad pot cause this?

 

[michaelandrew]

I am completely on the sideline in this debate/argument, but this was just too funny to pass up.

So a small democratic vote doesn't decide whether or not star grounding works, but a big democratic vote does?

If physics was something you could decide by popular vote, us old farts would have cancelled gravity long ago.

There's no question of whether star grounding works - it does.

There's also no question of whether it's necessary in bass guitar wiring - it isn't.

As long as the DC resistance between any two ground points is less than a few milliOhms, star ground or not - won't make any audible difference. Personally, I used a star ground when I installed a new pre-amp, just because I find it's a convenient way of keeping track of all the ground wires.

I'm now off to look for more information on EMI (Electro-Magnetic Interference - fancy term for noise) reduction in pick-ups. I'll report back if I find anything useful.