# Lifting the Ground



## vadsy (Dec 2, 2010)

I was playing out recently and a few of us had a good buzz going in our amps. I assumed it was the stage lights or something similar because I usually don't have this problem but in this case I was willing to put up with it. One of the other guys wasn't and he pulled out a very short extension cord with the ground prong removed, he called it "lifting the ground". I know this was common practise back in the day as amps even had a switch for this, correct me if I'm wrong here. I now see and hear techs putting new power cords on old amps with the 3 prongs. Besides the safety factor, what potential problem could come to the amp with having the ground removed?


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## jb welder (Sep 14, 2010)

Strictly a safety issue.


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## bluzfish (Mar 12, 2011)

If you are connected physically in any way to other systems such as the mains or monitors that are plugged into various AC outlets, there may be more than one path to ground which will cause buzz and hum. Lifting the AC ground on the amp eliminates one of those paths. I have a bunch of AC adapters for that. Of course, plug polarity then may become an issue you can fix by reversing the plug. Ideally everything should find one path to ground through the mains console.


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## ronmac (Sep 22, 2006)

Run Away From The Stage! Lifting AC Ground can lead to a fatal outcome and should NEVER be a solution to a ground hum issue. 

The FIRST thing I do when I scope a room or stage is plug one of these in to each AC outlet that I can find (even if it is not going to be used).








If ANY of the lines fail, I am outta there, and will report the issue to whoever is in charge of the facility. I DO NOT work in any facility (or with any individual) that does not take electrical safety seriously.

If you are lucky enough to survive an industrial accident, you do not want to be the one filling out the incident reports...


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## blam (Feb 18, 2011)

when I exercise I don't pull myself up for a chin-up, I lift the ground!!!!!11 or something like that.... I don't know....

Vadim, aren't you an electrician or something similar?


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## nonreverb (Sep 19, 2006)

Although other issues can be at play such as ground loops, I have to agree with ronmac on this one. You just never know who's been fiddling with the power in many venues and I've seen my fair share of horrid wiring jobs and octopus extensions not to mention the resulting damaged amps from some unscrupulous venue's power surprise. This little device is a must-have if you plan on playing out a lot.



ronmac said:


> Run Away From The Stage! Lifting AC Ground can lead to a fatal outcome and should NEVER be a solution to a ground hum issue.
> 
> The FIRST thing I do when I scope a room or stage is plug one of these in to each AC outlet that I can find (even if it is not going to be used).
> View attachment 8028
> ...


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## vadsy (Dec 2, 2010)

blam said:


> Vadim, aren't you an electrician or something similar?


Similar but not very good at what I do.

Seriously though, grounding is probably the most important thing in ANY electrical project and shouldn't be taken lightly. I was just wondering how it plays out in tube amps, an area I know way less about than the more common electrical fields. For the record everything I own and will buy in the future is and will be grounded. I do not clip or remove the ground prongs from my equipment. I learned my lesson back in the day when someone gave me an old Harmony bass amp, it had the old 2 prong cord. I used to dime that thing and get some great tones out of that single 15" speaker but if I ever touched the chassis while the amp was on it would send a shock through me in a most uncomfortable way. The amp is long gone. My question was more towards "what happens if?" modern tube amps have the ground disconnected. I know that safety of the person(s) around and the equipment is out the window but if anyone had anything different to add regarding the inner workings of a tube amp, I was curious. I should also mention the guy who "lifted the ground" while we were playing didn't get better results and switched back to using the 3 prong chord.


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## loudtubeamps (Feb 2, 2012)

bluzfish said:


> If you are connected physically in any way to other systems such as the mains or monitors that are plugged into various AC outlets, there may be more than one path to ground which will cause buzz and hum. Lifting the AC ground on the amp eliminates one of those paths. I have a bunch of AC adapters for that. Of course, plug polarity then may become an issue you can fix by reversing the plug. Ideally everything should find one path to ground through the mains console.


Once proper polarity has been established with a tester as mentioned, I would agree 100% with this ^^^^^^^^^^^^^.
Just to clarify, once any chassis ground(s) have been lifted via a ground lift adaptor and the low freq. 60/120 cps hum has been reduced, do not disconnect any other audio cables (tied to chassis ground) that are in the chain, doing so will interrupt the ground path and may increase the risk of being shocked.
At least one audio device in the chain must remain grounded to earth.
Any 19" rack mounted outboard audio gear secured by a common metal bar is also a typical source for a potential ground loop. 
If the rack gear has not been properly configured to eliminate ground loops and if you are connected to this via the mixing console, it can cause your amplifer to hum as well.
If what u are describing is more of a buzzing rather than a low hum (which is typical of a ground loop symptom) then it may be a polarity issue or an interference caused by dimmers or fluorescent lighting ballasts on the A.C. branch line that U may be sharing with one of these devices. As well, close proximity to any electronic (including digital) devices that may be emitting E.M.I. Electromagnetic interference - Wikipedia, the free encyclopedia is easily amplified through instruments, especially those using single coil pickups.
FWIW. Here is a link to a page from the owners manual that is included with the amplifiers that I design and build addressing the issue of ground loops. 
Cheers, doug
http://i1132.photobucket.com/albums/m570/loudtubeamps/LOUD TUBE AMPS Owners Manual/Manual4.jpg


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## bluzfish (Mar 12, 2011)

loudtubeamps said:


> Once proper polarity has been established with a tester as mentioned, I would agree 100% with this ^^^^^^^^^^^^^.
> Just to clarify, once any chassis ground(s) have been lifted via a ground lift adaptor and the low freq. 60/120 cps hum has been reduced, do not disconnect any other audio cables (tied to chassis ground) that are in the chain, doing so will interrupt the ground path and may increase the risk of being shocked.
> At least one audio device in the chain must remain grounded to earth.
> Any 19" rack mounted outboard audio gear secured by a common metal bar is also a typical source for a potential ground loop.
> ...


I see you've done this before... ;-)

Good summary.


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## Steadfastly (Nov 14, 2008)

ronmac said:


> Run Away From The Stage! Lifting AC Ground can lead to a fatal outcome and should NEVER be a solution to a ground hum issue.
> 
> The FIRST thing I do when I scope a room or stage is plug one of these in to each AC outlet that I can find (even if it is not going to be used).
> View attachment 8028
> ...


I too have to agree with Ron on this. It's just not smart playing around with unprotected gear. I, personally, have not heard of anyone dying by a shock from musical equipment but I do know of ones who got shocked pretty good. Some even kept on playing! Now that was downright stupid.


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## vadsy (Dec 2, 2010)

Steadfastly said:


> I do know of ones who got shocked pretty good. Some even kept on playing! Now that was downright stupid.


Show must go on, those folks had their priorities in order.


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## cdayo (Jan 28, 2014)

And lest we forget the hardest lesson of them all

http://en.wikipedia.org/wiki/Keith_Relf#Personal_life_and_death

You COULD choose to go this way and become a rocknroll legend. Just make sure you record a few hit albums before you decide to go


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## Wild Bill (May 3, 2006)

ronmac said:


> If ANY of the lines fail, I am outta there, and will report the issue to whoever is in charge of the facility. I DO NOT work in any facility (or with any individual) that does not take electrical safety seriously.
> 
> If you are lucky enough to survive an industrial accident, you do not want to be the one filling out the incident reports...


By any chance Ron, are you a CUPE member?

I can see it now. A band gets its first gig at a local club. They use one of those testers and find a wiring mistake. They tell the owner "Fix this safety issue immediately or we are not going on!"

"Fine by me!" says the owner. "Good bye!"

The band of course is now disappointed to have lost their first gig. So they report the club to Ontario Hydro or whoever as a safety violation. It takes about a year before Ontario Hydro gets around to checking it out. They tell the owner to get it fixed and then leave for another appointment at a nearby Tim Hortons.

Meanwhile, the owner is now pissed and remembers the band who first complained. He tells ALL his owner friends and that band never gets another gig in that town again.

At the same time, Bluzfish had a band who played the same club. Bluzfish had researched such problems and understood how these things actually worked! He constructed his own adapters and was able to cure his own ground problems, safely!

The owner LOVES Bluzfish's band! He makes them his house band and they play there every Saturday night, forever. Since they have such a good relationship with the owner, they calmly speak to him about the problems with some of his outlets. Bluzfish, as I had said, had educated himself on such things and offers to fix them himself. That way he doesn't need all his adapters!

The owner and Bluzfish become such good friends that Bluzfish marries the owner's daughter! The owner has a cousin who is a big name record label manager and the Bluzfish Band gets a world tour deal! They become rich and famous!

The original band that did all the righteous complaining never goes anywhere. The lead singer who instigated the high handed complaint to the authorities is reduced to covering Ice T rap songs at weddings.

Wild Bill/Busen Amps

- - - Updated - - -


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## ronmac (Sep 22, 2006)

Bill, not a member of CUPE. Not sure why that question...

It's a nice story ya spun there, but it doesn't change my mind in the least. If a club, or any other facility with a working stage, doesn't give two hoots about their equipment, or fix it immediately when a major fault is pointed out to them, I have no interest in working there. Period.


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## bluzfish (Mar 12, 2011)

Wild Bill said:


> By any chance Ron, are you a CUPE member?
> -------------------------------------
> The owner and Bluzfish become such good friends that Bluzfish marries the owner's daughter! The owner has a cousin who is a big name record label manager and the Bluzfish Band gets a world tour deal! They become rich and famous!


Oh, I wish it could be that I should live in the alternate universe you describe...

I remember doing gigs at The Orpheum, QE Playhouse, and other union houses. We had to hire IATSE union 'shadows' for every crew member. They would just follow us around, shootin the shit. They had no real interest in the gig - they were just there for contractual obligations. No problem, but it was a little weird having a guy hanging around while I worked.

One summer, our company was stretched to max equipment-wise with most of the gear out on the Synchronicity tour, the house system at the Commodore and 2 full Folk Festival systems. The Synchronicity tour was due back in town for a Coliseum show and we needed to have all our gear CSA approved for the union house. The only thing left to have inspected were the lighting racks and I only had two 8-PAR racks and a couple of AC service panels in the warehouse. The CSA inspector shows up and I easily convince him that all the other equipment on the trucks is identical. So he says okay, sight unseen, and gives me a couple of fistfuls of official CSA Approved stickers to put on anything I wanted and asks me if I need more! So much for electrical safety.


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## Steadfastly (Nov 14, 2008)

vadsy said:


> Show must go on, those folks had their priorities in order.



At the expense of their safety and lives?

- - - Updated - - -



Wild Bill said:


> By any chance Ron, are you a CUPE member?
> 
> I can see it now. A band gets its first gig at a local club. They use one of those testers and find a wiring mistake. They tell the owner "Fix this safety issue immediately or we are not going on!"
> 
> ...


Wow, Bluzfish has never mentioned any of this to us before.:smile-new:


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## vadsy (Dec 2, 2010)

Steadfastly said:


> At the expense of their safety and lives?


Yea! In the name of rock 'n roll.


Seriously though, joke.


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## nonreverb (Sep 19, 2006)

Indeed, and further, the money made playing in most venues is so little, who gives a crap if some dive won't have you back? They usually forget who was in what band after a while anyway. 
The good venues who actually give a shit about that kind of stuff are the ones you want to concentrate on. 
Remember, most here don't make a living playing music so it's not the end of the world....and those who do, have already accepted their fate.



ronmac said:


> Bill, not a member of CUPE. Not sure why that question...
> 
> It's a nice story ya spun there, but it doesn't change my mind in the least. If a club, or any other facility with a working stage, doesn't give two hoots about their equipment, or fix it immediately when a major fault is pointed out to them, I have no interest in working there. Period.


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## Wild Bill (May 3, 2006)

To put things more clearly, my story was meant to show that first of all, most of the times these problems are not really dangerous or unsafe IF YOU TAKE THE TROUBLE TO LEARN ABOUT THEM AND HOW TO HANDLE THEM!

Taking a righteous attitude with a club owner is not the best way to "Win Friends and Influence People". Club owners are usually running on a shoe string. If they have a wiring problem its usually because it was that way when they bought it and they can't afford to have it all checked out and fixed. Nobody wants to see someone hurt, however. A civil discussion instead of a hardass attitude will likely bring more positive results. You get more flies with honey...

Adapters to lift grounds can be perfectly safe and workable solutions to ground loop problems. There has always been a conflict between the Electrical Code and much audio electronic equipment. A good ground for safety or lightning can sometimes be the worst possible choice for a ground hum. I often get amps in my shop that have been hacked by someone who thinks that you can ground parts of a circuit anywhere, like putting extra lights in a truck and running the ground return through the nearest point of bare metal. Their amp now hums like hell! Re-arranging the grounds in a proper manner cures the problem.

I just felt that Ron was being a bit too righteous, that's all. In the real world, I don't think that kind of owner-band relations usually works out very well. A bit of education on what actually makes wiring unsafe and how to fix it, along with how to do it when eliminating hum from ground loops can solve things without getting someone's nose out of joint.

My CUPE reference was in regards to the usual attitude of government union workers, who can throw rule books around without the slightest care about how much it would cost their employer.

Some of you young pups would have been horrified at what touring bands did all the time in small old clubs back in the late 60s and 70s. If the house wiring was a mess we would just open up the main panel and clamp on to the mains, using vise grip pliers! We would have our own distribution panel, providing breakers, outlets and of course, proper grounding for all our stage equipment. We would throw a blanket over the vise grips and keep an eye out so that no idiot would get anywhere near the open voltage.

We could have made hard nose demands but it would have meant that we would have played nowhere near as many clubs as we did! We would be on the road week after week for months on end. I never heard of any of us injured or electrocuted. If we had, we would have dismissed it as an example of a Darwin Award. If a band tech was too stupid or lazy to educate himself on basic electrical wiring and take precautions HIMSELF then while we would have been sorry for him we would have felt he did it to himself and deserved what he got!

Wild Bill


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## Rodavision (Feb 26, 2010)

^ Along those lines, several older electricians I know think nothing of a little jolt here and there, but they are also extremely militant about what is unsafe. I guess it comes down to knowing the difference between what is not a big deal or what is some really dangerous wattage, as well as how to discuss these topics with property owners.


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## bluzfish (Mar 12, 2011)

Wild Bill said:


> Some of you young pups would have been horrified at what touring bands did all the time in small old clubs back in the late 60s and 70s. If the house wiring was a mess we would just open up the main panel and clamp on to the mains, using vise grip pliers! We would have our own distribution panel, providing breakers, outlets and of course, proper grounding for all our stage equipment. We would throw a blanket over the vise grips and keep an eye out so that no idiot would get anywhere near the open voltage.


That reminds me of the time I was setting up in a brand new club. I went to the electrical room to wire up our AC service and found the main panel locked and a sub-panel wired into it with all black wires on a terminal block and no breakers. First, I figured out which was ground but I had no idea which ones were neutral and hots.

I took my best guess and began screwing down my service to the terminal block but the way it was mounted made the block difficult to get into. As I was tightening down one of the wires, my screwdriver touched the ground terminal and sent it flying across the room and embedded it into the wall behind me with a deep notch in the blade from where it had shorted out. Fortunately, I was following the 'one hand in your pocket' rule and I was using my heavy duty heavily insulated electrical panel screwdriver and wearing rubber soles. Unfortunately, the neutral and ground were wired together somewhere - in a brand new building!

I've had many full on AC shocks in my time and lived to tell the tale. Maybe it was from blindly experimenting with guitar amp guts. Or maybe I built up a tolerance from when my cousin and I used to put our hands on the terminals of a manual WW II field generator while the other cranked the generator to see who could hold on the longest. Our moms made us promise to stop doing that.


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## Steadfastly (Nov 14, 2008)

bluzfish said:


> Or maybe I built up a tolerance from when my cousin and I used to put our hands on the terminals of a manual WW II field generator while the other cranked the generator to see who could hold on the longest. Our moms made us promise to stop doing that.


You sound like you're from the same kind of background as me. You had to make your fun where you could. 

It reminds me of my brother-in-law's Dad who would grab a spark plug end from a running engine and then grab us by the arm. For some reason he could hang on but we sure couldn't.


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## jb welder (Sep 14, 2010)

bluzfish said:


> Unfortunately, the neutral and ground were wired together somewhere - in a brand new building!


 You got me a little confused here, neutral is always supposed to be bonded to ground at the electrical service entrance. If they were not wired together in a brand new building I would be alarmed.


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## Guest (Apr 29, 2014)

vadsy said:


> Show must go on, those folks had their priorities in order.


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## Rodavision (Feb 26, 2010)

jb welder said:


> You got me a little confused here, neutral is always supposed to be bonded to ground at the electrical service entrance. If they were not wired together in a brand new building I would be alarmed.


Maybe all the blacks were hot and the screwdriver found 220 V! 

Sent from my XT925 using Tapatalk


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## Fader (Mar 10, 2009)

Rodavision said:


> Maybe all the blacks were hot and the screwdriver found 220 V!
> 
> Sent from my XT925 using Tapatalk


Sounds to me like he tapped into the splitter trough of a 3 phase delta system ahead of any wye connected transformers.


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