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Noise while plugged into some outlets but not others. Compact Solutions?

sixtystring

Inspired
Example of noise I am referring to: https://www.sweetwater.com/sweetcare/media/2017/09/Guitar-Noise-Buzz-and-Hum-Dirty-Power.mp3?_=4

This type of noise occurs with these setups, but not on all power outlets:
  • Guitar > 1/4 TS Cable > FM3 Input 1 > Monitoring via Headphone out
  • Guitar > 1/4 TS Cable > FM3 Input 1 > output 2 L > 1/4 TS Cable > Seymour Duncan powerstage > speaker cable > cab
Only some of the outlets in my house cause ground loop buzz, while others do not. I used a ground tester to ensure that both the noisy outlets and non-noisy ones are properly grounded. I'm assuming the noisy outlets may be caused by something else in the circuit. (EDIT: Traced the source to a light fixture on the same circuit.) Which brings me to my question...

What do you do in this type of situation, especially when a lot of venues have sketchy power? Since it occurs with headphones as well, I’m not sure using a humbuster cable really applies (EDIT 2: humbuster probably WOULD solve this in a live situation...see post 3 below EDIT of EDIT maybe not)

My full setup for live will be this:
  • Guitar > 1/4 TS Cable > FM3 Input 1
  • FM3 Output 1 L > FOH
  • FM3 Output 2 L > 1/4 TS Cable (or humbuster if necessary) > Seymour Duncan Powerstage > Speaker Cable > Cab
  • The FM3 will also have an EV1 and FC6 hooked up.
Since the FC6 is powered via the FM3, I should only need power for the FM3 and PowerStage. What are some compact recommendations to properly and safely ensure that no matter what outlet I plug into I won't run into this issue?

Would either of these solve the issue?
EDIT NO IT WONT: https://www.sweetwater.com/store/detail/AC215--furman-ac-215a-power-conditioner
https://www.sweetwater.com/store/detail/MHumX--morley-hum-exterminator-ground-loop-hum-exterminator
 
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sixtystring

Inspired
Thinking about this some more...

The headphone out doesn't seem to have a "built in" way of defeating ground hum caused by a power outlet. However, in a live scenario, you presumably wouldn't be using the headphone out. You'd instead be using Out 1 to FOH and Out 2 to your poweramp/cab. Using a Humbuster cable from Out 2 should resolve this issue in a live scenario.

Edit: maybe not --- see post 4?
 
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unix-guy

Legend!
Thinking about this some more...

The headphone out doesn't seem to have a "built in" way of defeating ground hum caused by a power outlet. However, in a live scenario, you presumably wouldn't be using the headphone out. You'd instead be using Out 1 to FOH and Out 2 to your poweramp/cab. Using a Humbuster cable from Out 2 should resolve this issue in a live scenario.
If it's from power then you'd hear it regardless.

The Humbuster is designed to eliminate noise caused by connecting from the Fractal to an amp with an unbalanced cable.

In your edited post you mentioned you identified the source as a light fixture. Does it have a dimmer switch or use an LED bulb? Both are notorious sources of this kind of issue... As are neon signs you often find in clubs. Hint: stay away from those if you can :)
 

sixtystring

Inspired
If it's from power then you'd hear it regardless.

The Humbuster is designed to eliminate noise caused by connecting from the Fractal to an amp with an unbalanced cable.

In your edited post you mentioned you identified the source as a light fixture. Does it have a dimmer switch or use an LED bulb? Both are notorious sources of this kind of issue... As are neon signs you often find in clubs. Hint: stay away from those if you can :)
It's an old light fixture (probably not grounded) and I think it has LED bulbs in it as well, no dimmer switch.

So, I guess my question still stands: would some sort of power conditioner be the way to go presuming you're plugging into a "bad" outlet at a venue or practice space? Or is there a more compact and/or better solution?
 

unix-guy

Legend!
It's an old light fixture (probably not grounded) and I think it has LED bulbs in it as well, no dimmer switch.

So, I guess my question still stands: would some sort of power conditioner be the way to go presuming you're plugging into a "bad" outlet at a venue or practice space? Or is there a more compact and/or better solution?
A power conditioner isn't likely to help.
 

sixtystring

Inspired

James Nash

Inspired
So do you just use a circuitry tester on the outlets and use one that passes? Or did you find another solution moving forward?
Didn't have any testing equipment at the venue. We tried running extension cords to all the AC outlets remotely near the stage, and had the same problem with all.

Never had this problem in any other venue with this rig. Such an unusual occurrence, we just moved on and forgot about it. (For that particular show, we just gave up running any DI lines to FOH)

Would be awesome if there were some power conditioning device that would reliably compensate for these "bad wiring" issues, but sounds like maybe not. First step would be diagnosing the precise problem... sorry I can't help there :)
 
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oakworka

Member
Furman units do this - search for AC power filter as they've got filtration for dirty power as well as current stabilizers in case you get an unsteady current from your wall sockets. They can be a bit expensive, but probably more viable than moving to a new house!
 

Sleestak

Power User
I have experienced a lot of noisy power on tour. I have some strategies, but first let me ask a few questions.
  • What kind of guitar pickups do you have? Single coil pickups are susceptible to RF noise and line hum. There are ways to mitigate (or at least reduce it).
  • Does the noise change if you physically move / turn your guitar while playing?
 

Rex

Legend!
I have experienced a lot of noisy power on tour. I have some strategies, but first let me ask a few questions.
  • What kind of guitar pickups do you have? Single coil pickups are susceptible to RF noise and line hum. There are ways to mitigate (or at least reduce it).
  • Does the noise change if you physically move / turn your guitar while playing?
Good questions. Electromagnetic interference is often confused with bad power, and vice versa.
 

Nor

Member
Google
'XLR ground filter'
The stage and the console are apparently using different grounding points. The XLR filters can help a lot. I usually end up using a combo: XLR filter+AC ground lift at the stage. Usually minimizes, or eliminates the hum.
 

sixtystring

Inspired
I have experienced a lot of noisy power on tour. I have some strategies, but first let me ask a few questions.
  • What kind of guitar pickups do you have? Single coil pickups are susceptible to RF noise and line hum. There are ways to mitigate (or at least reduce it).
  • Does the noise change if you physically move / turn your guitar while playing?
Humbuckers. The noise does change some while turning my body.

Just to reiterate: this only occurs on certain circuits in my house (and presumably practice spaces/venues as well), so I'm not sure it's an EMI thing unless that area just has a ton more EMI. The noise also stops when I turn off the light switch on that same circuit.

Sescom IL-19
Industry standard. So common in audio workboxes that 'IL-19' is synonymous with XLR ground lift.
This seems like it may be useful, but FM3 output 1 has a built in XLR ground lift.

In my situation I'm just trying to eliminate the noise with the below setups. Output 2 is unbalanced.
  • Guitar > 1/4 TS Cable > FM3 Input 1 > Monitoring via Headphone out
  • Guitar > 1/4 TS Cable > FM3 Input 1 > output 2 L > 1/4 TS Cable > Seymour Duncan powerstage > speaker cable > cab
 

Rex

Legend!
Humbuckers. The noise does change some while turning my body.

Just to reiterate: this only occurs on certain circuits in my house (and presumably practice spaces/venues as well), so I'm not sure it's an EMI thing unless that area just has a ton more EMI. The noise also stops when I turn off the light switch on that same circuit.


This seems like it may be useful, but FM3 output 1 has a built in XLR ground lift.

In my situation I'm just trying to eliminate the noise with the below setups. Output 2 is unbalanced.
  • Guitar > 1/4 TS Cable > FM3 Input 1 > Monitoring via Headphone out
  • Guitar > 1/4 TS Cable > FM3 Input 1 > output 2 L > 1/4 TS Cable > Seymour Duncan powerstage > speaker cable > cab
Ah! Clues!

The noise changes as you move around. That means it's coming through the air into your guitar. I bet it goes away completely when you unplug your guitar cord from your FM3.

The noise goes away when you turn off the light. I guess the light is the culprit.
 

Rex

Legend!
Ah! Clues!

The noise changes as you move around. That means it's coming through the air into your guitar. I bet it goes away completely when you unplug your guitar cord from your FM3.

The noise goes away when you turn off the light. I guess the light is the culprit.
From my own experience, "dirty power" is rarely the problem. It's usually interference from some gadget.
 
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