Elec. Gtr/Bass buzz/hum??

[manthe]

Hello all. I've just finished moving and vastly upgrading my home-based project studio. I had my 1st customer in this weekend for for 4.5 days. Everything went really great except for a consistent buzz/hum coming from any electric guitar or bass that was plugged into any of my DIs. I use the GT Brick (2 of them) for DI boxes. They have ground lift switches on them. I tried several different cables (balanced and unbalanced). Unless the players kept the strings or pick-ups grounded with their hands, we got a bad buzz. i remember dealing with this while playing live all of the time when i was younger.

We tried with 5 or 6 different instruments, and they all had the same issue. What causes this, and what can be done to fix it? Would this help:

http://www.sweetwater.com/store/detail/HE8/

?

Thanks!

[Kiwiburger]

Trouble shooting guitar hum can be very difficult. I recommend you buy a little battery amp (they are very useful in a studio). The beauty of a battery amp is that they are totally isolated from your AC and AC ground, and therefore you can quickly tell if the buzz is airborne or conducted via your AC.

If your buzz goes away when using a battery amp, it's probably coming through the AC earth. If the buzz remains when using a battery amp, it's airborne. See if it has a directional source by moving your pickups around. A cheap single coil pickup (and acoustic woody is fine) plugged into a battery amp is a great hum finder.

You need to understand what happens when you place your hands on the strings. It is NOT grounding the guitar. You can prove this easily, by connecting a wire from guitar strings to electrical earth. If it was that easy, I would be selling a simple device to do exactly this. Your guitar (usually) is well connected to ground, via the cable to the amp. Your guitar does not need more grounding ... did I mention that?

What is actually happening is that you are grounding your body! If you are wearing shoes and standing on carpet, you are not very well grounded. Although everthing is relative - if you connect 240VAC to your body, you will be suffiently close to ground to get fried to a crisp.

The human body is a complicated semi-conductor with a lot of capicitance. It can function like a ground, or it can function like an antenna. It's a real problem to guitar pickups. The human body is mostly water and minerals - it's like a pile of dirty water to electrics.

If you have sources of EMI in your room (transformers etc) then your body can work like a antenna or conductor, and brings the hum right up to your guitar. You might notice this when using a single coil guitar and battery amp.

With an AC grounded amp, your guitar strings are grounded (usually) so touching them grounds your body. Suddenly, instead of being a big antenna, you are now a big ground, and you work like a big shield.

If your guitar and pickups are well designed in the first place, this shouldn't matter. But Fender and other cut-cost makers don't seem to care about shielding and grounding, so they connect your strings up to electrical earth. This will kill you if your amp short circuits, but what do they care?

EMG has a better idea - they make silent pickups that are well shielded, and don't depend on your sacrificial body being placed around them to shield from EMI. Many top players use EMG pickups. EMG advise against connecting your strings to ground, so you can't fry yourself on stage.

All this information is totally useless if you have a contaminated electrical earth. In my case, I had 1.5VAC on my electrical earth (relative to a spike in the ground). It created a horrendous buzz, and none of the expensive electrical gurus I employed could do a damn thing about it. Waste of time, money and hair.

The theory is that your electrical ground is at zero earth potential. The practice can be very different - especially with old wiring and dried up ground spikes. If you can see your ground spike - give it some water.

If everyone in your neighbour has poor earth too, then if you put in a better ground spike, you suddenly have the best earth and all the noise and crap gets diverted into your backyard. Been there, done that, and it's unworkable.

Total isolation - via transformer, balanced or otherwise, or via UPS - allows you to have a pure isolated earth of your own that isn't connected to this crap.

Audio circuits depend on shielded wires, connected to earth, to shield your signal from hum. If your electrical earth is not at zero potenial, and is carrying a low voltage AC current, then your shields are contaminated and you will have hum and buzz forever. Nothing you will try will solve this.

I expect all the arm chair electrical experts to now proceed to roast me for providing crap information. Especially if they haven't personally experienced these sorts of problems.

Usual internet disclaimers ... don't play with electricity, pay the experts to do it, yada, yada ... just be prepared to spend lots of money on people who have zero clues how to solve these issues.

[Sqye]

..

man - that ain't NUTHIN'

let us know when you got summa that DINAH-MOE HUM..

..

[manthe]

WHEW! That was fantastic....and dis-heartening! So...what did you do about it? Is there anything I can do in my room to battle this. Can I isolate my racks on to batteries?

It is amazing that a 1200 guitar could have such a thoughtless design! We tried 5 or 6 different guitars/bass guitars (some cheap, some NOT), and they all had the same issue. I will pick up a little Pignose or some similar battery amp. That is a GREAT idea for testing.

Any other tips?

Originally Posted by Kiwiburger

Trouble shooting guitar hum can be very difficult. I recommend you buy a little battery amp (they are very useful in a studio). The beauty of a battery amp is that they are totally isolated from your AC and AC ground, and therefore you can quickly tell if the buzz is airborne or conducted via your AC.

If your buzz goes away when using a battery amp, it's probably coming through the AC earth. If the buzz remains when using a battery amp, it's airborne. See if it has a directional source by moving your pickups around. A cheap single coil pickup (and acoustic woody is fine) plugged into a battery amp is a great hum finder.

You need to understand what happens when you place your hands on the strings. It is NOT grounding the guitar. You can prove this easily, by connecting a wire from guitar strings to electrical earth. If it was that easy, I would be selling a simple device to do exactly this. Your guitar (usually) is well connected to ground, via the cable to the amp. Your guitar does not need more grounding ... did I mention that?

What is actually happening is that you are grounding your body! If you are wearing shoes and standing on carpet, you are not very well grounded. Although everthing is relative - if you connect 240VAC to your body, you will be suffiently close to ground to get fried to a crisp.

The human body is a complicated semi-conductor with a lot of capicitance. It can function like a ground, or it can function like an antenna. It's a real problem to guitar pickups. The human body is mostly water and minerals - it's like a pile of dirty water to electrics.

If you have sources of EMI in your room (transformers etc) then your body can work like a antenna or conductor, and brings the hum right up to your guitar. You might notice this when using a single coil guitar and battery amp.

With an AC grounded amp, your guitar strings are grounded (usually) so touching them grounds your body. Suddenly, instead of being a big antenna, you are now a big ground, and you work like a big shield.

If your guitar and pickups are well designed in the first place, this shouldn't matter. But Fender and other cut-cost makers don't seem to care about shielding and grounding, so they connect your strings up to electrical earth. This will kill you if your amp short circuits, but what do they care?

EMG has a better idea - they make silent pickups that are well shielded, and don't depend on your sacrificial body being placed around them to shield from EMI. Many top players use EMG pickups. EMG advise against connecting your strings to ground, so you can't fry yourself on stage.

All this information is totally useless if you have a contaminated electrical earth. In my case, I had 1.5VAC on my electrical earth (relative to a spike in the ground). It created a horrendous buzz, and none of the expensive electrical gurus I employed could do a damn thing about it. Waste of time, money and hair.

The theory is that your electrical ground is at zero earth potential. The practice can be very different - especially with old wiring and dried up ground spikes. If you can see your ground spike - give it some water.

If everyone in your neighbour has poor earth too, then if you put in a better ground spike, you suddenly have the best earth and all the noise and crap gets diverted into your backyard. Been there, done that, and it's unworkable.

Total isolation - via transformer, balanced or otherwise, or via UPS - allows you to have a pure isolated earth of your own that isn't connected to this crap.

Audio circuits depend on shielded wires, connected to earth, to shield your signal from hum. If your electrical earth is not at zero potenial, and is carrying a low voltage AC current, then your shields are contaminated and you will have hum and buzz forever. Nothing you will try will solve this.

I expect all the arm chair electrical experts to now proceed to roast me for providing crap information. Especially if they haven't personally experienced these sorts of problems.

Usual internet disclaimers ... don't play with electricity, pay the experts to do it, yada, yada ... just be prepared to spend lots of money on people who have zero clues how to solve these issues.

[Sigma]

Originally Posted by manthe

Hello all. I've just finished moving and vastly upgrading my home-based project studio. I had my 1st customer in this weekend for for 4.5 days. Everything went really great except for a consistent buzz/hum coming from any electric guitar or bass that was plugged into any of my DIs. I use the GT Brick (2 of them) for DI boxes. They have ground lift switches on them. I tried several different cables (balanced and unbalanced). Unless the players kept the strings or pick-ups grounded with their hands, we got a bad buzz. i remember dealing with this while playing live all of the time when i was younger.

We tried with 5 or 6 different instruments, and they all had the same issue. What causes this, and what can be done to fix it? Would this help:

http://www.sweetwater.com/store/detail/HE8/

?

Thanks!

do you have light dimmers in the house?...any neon lights nearby?

do you have a radiator for heating nearby..grounding the guitar body to earth with a nice braided wire can be tried also

[TAVD]

Try one of those ground straps that computer techs wear. One end wraps around your wrist and the other clips to a ground.

[Kiwiburger]

A groundstrap doesn't work as good as the old nashville trick of winding some copper wire around your finger and attaching it with an alligator clip to your bridge.

Or the practice of stuffing a bunch of aluminium foil into your pants, to connect a good earth connection to your butt.

They work on the principle I mentioned above - turning your body from being an antenna into a grounded shield. It's a workaround for poorly shielded guitars.

But if your audio shields have low voltage AC, you will still get a nasty buzz.

The purest earth is a copper or stainless steel spike driven into moist earth. If your audio shields are connected to that, noise is kept to a minimum (depends on the quality of your shield). If you are forced to connect to a noisy electrical ground that is contaminated with stray AC currents, you are stuffed.

[manthe]

You're just full of bad news, aren't you?

I guess I'll get an electrician out to check my earth ground. My studio (which is built in my home), comes off of a separate box than the rest of the house. It is tied back to the box that is tied to the street power. Perhaps i can get better grounds on both boxes!

Here's hoping..

Thanks for all of your help!

Originally Posted by Kiwiburger

A groundstrap doesn't work as good as the old nashville trick of winding some copper wire around your finger and attaching it with an alligator clip to your bridge.

Or the practice of stuffing a bunch of aluminium foil into your pants, to connect a good earth connection to your butt.

They work on the principle I mentioned above - turning your body from being an antenna into a grounded shield. It's a workaround for poorly shielded guitars.

But if your audio shields have low voltage AC, you will still get a nasty buzz.

The purest earth is a copper or stainless steel spike driven into moist earth. If your audio shields are connected to that, noise is kept to a minimum (depends on the quality of your shield). If you are forced to connect to a noisy electrical ground that is contaminated with stray AC currents, you are stuffed.

[Kris]

Along the lines of Kiwiburger's technique, you could also take an old or unused bass or guitar string... wrap it around the bridge and shove it down your pants.

[kyle barton]

So your using DI boxes AND amps at the same time...
so the signal chain would be
1. guitar -> DI
2. DI -> amp
3. DI -> DAW

if that IS what your doing, then you have a ground loop happening between the amp plugged into outlet#1 and the DAW plugged into outlet#2. you can use an isolation box in front of the amp input if that is the case. there are several manufacturers of these things including furman, axess electronics and other. and no, i don't work for any of those people, i had to find this solution because i was having the same problem.

if thats NOT what your doing, then i wonder what is different between this recording setup and the work you normally do with your guitar that isn't creating hum?

[manthe]

Originally Posted by Kris

Along the lines of Kiwiburger's technique, you could also take an old or unused bass or guitar string... wrap it around the bridge and shove it down your pants.

You people seem to have a peculiar fascination with me putting things down my pants...

[Kris]

Just try it... you know you'll like it!

[manthe]

There is no amp in the chain. It goes Guitar/Bass -> DI -> DAW

I do not play out live any more, so the only time the guitars get any action is when I or a customer uses them in the studio. Unfortunately, having just relocated the studio from one area to a new area in my home...troubleshooting will be a little difficult. Not impossible, but very cumbersome.

I will probably pick up a battery-powered amp, as suggested earlier, as well as your recommendation of an isolater/hum eliminator.

I will also talk to my electrician about my Earth grounds and probably have him come out to check them.

i hope this does not turn out to be too expensive or time consuming. i just dropped A LOT of money on this recent move!

Originally Posted by kyle barton

So your using DI boxes AND amps at the same time...
so the signal chain would be
1. guitar -> DI
2. DI -> amp
3. DI -> DAW

if that IS what your doing, then you have a ground loop happening between the amp plugged into outlet#1 and the DAW plugged into outlet#2. you can use an isolation box in front of the amp input if that is the case. there are several manufacturers of these things including furman, axess electronics and other. and no, i don't work for any of those people, i had to find this solution because i was having the same problem.

if thats NOT what your doing, then i wonder what is different between this recording setup and the work you normally do with your guitar that isn't creating hum?

[mrface2112]

i had a problem with this almost inaudible, high-pitched ringing through my single coil pickups (strat, tele and PBass). it would go away when i touched the strings or bridge, etc., but when not touched, it would be really loud. i have no dimmers or anything, so it was definitely a grounding issue.

so i went to BanjoMart and i asked the guy for a "double shielded cable". he came back with a $40 monster cable (one of the 500 series cables--not the "rock" or "bass" cables).

i plunked down my $$, took it home and plugged it in and my problem went away.

surely there are other double shielded cables out there (mogami and the like). the monster one was just the one he handed me and i figured what the heck. and although i don't buy into the monster hype and all that, i can say that this cable completely fixed the problem, and that's good enough for me.


cheers,
wade

[Stevil]

i noticed this phenomenon come & go in my recording setup. wonder if theres any ties to the amount of electricity "in the air" due to weather, solar flares, planet alignment, Raiden being angry...

[manthe]

Good idea. Worth a try. Although, I do use big, thick Monster instrument cables, I do not know if they are double shielded. i also tried balanced cables...

Originally Posted by mrface2112

i had a problem with this almost inaudible, high-pitched ringing through my single coil pickups (strat, tele and PBass). it would go away when i touched the strings or bridge, etc., but when not touched, it would be really loud. i have no dimmers or anything, so it was definitely a grounding issue.

so i went to BanjoMart and i asked the guy for a "double shielded cable". he came back with a $40 monster cable (one of the 500 series cables--not the "rock" or "bass" cables).

i plunked down my $$, took it home and plugged it in and my problem went away.

surely there are other double shielded cables out there (mogami and the like). the monster one was just the one he handed me and i figured what the heck. and although i don't buy into the monster hype and all that, i can say that this cable completely fixed the problem, and that's good enough for me.


cheers,
wade

[Protools Guy]

Turn off your monitor and see if it goes away.

[manthe]

Originally Posted by Protools Guy

Turn off your monitor and see if it goes away.

I'll give it a try. But, I use 2 LCD monitors...not CRT. So, I do not know if they put off the same interference. Still, every little suggestion is welcome!!

[Sigma]

you never rsponded aboutlight dimmers on that electr circuit or neon lights/toys

[manthe]

Originally Posted by SIGMA

you never rsponded aboutlight dimmers on that electr circuit or neon lights/toys

Ah yes...missed that one. There are dimmers near-by. But, I did set them in the 'fully-on' position. That is to say, that they 'click' at the top of the throw and are no longer in 'dimmer mode'. I'm not sure if that would still cause the traditional dimmer issues. There is also a set of fluorescent lights on the same breaker box, but not the same circuit.

As for buzzing toys, don't you think that's a bit private?

[rodrigo]

you could try upgrading all your power outlets, and tying an independent ground line for each power outlet; it's called Star grounding techinque. Go to www.johnlsayers.com to read more about it.

You could also try DI boxes with a Jensen transformer. Radial JDI uses them, and they're supposed to work great eliminating buzz caused by ground loops.

If you have the dough, you could also get a high isolation transformer with ultra low coupling capacitance from winding to winding. Or a balanced power device such as Equitechs.

You could go to Benchmark media's site and download a pdf called "A Clean Audio Installation Guide" by Allen H. Burdick if you're a real tech geek and are up for some reading.

Good luck