Fix your Audio Ground Loop Buzzes and Noises

Started by admin, November 21, 2009, 06:43:53 AM

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jshortz

I have been doing that however on some gigs I do get a hum.It may be some electrical issue at the venue.
I would like to come out of the XLR on the Alto into the DI versus the out on my 55.
Not sure if it makes a difference.

Elantric

#26
At some venues i get Hum if  I connect the GR-55/GP-10 straight to my Powered PA Cab  - inserting the box below between GR-55 and Alto TS12A solves the noise issue.  ( i use the similar Alesis Alpha 112A)

https://www.amazon.com/PYLE-PRO-PHE400-Eliminator-2-Channel-Outputs/dp/B00BARTW42/

jshortz

#27
Im not sure if an external DI will work coming out of the Alto and going to the PA from the DI.
In other words the order would be GR-55 into Alto.
From Alto to DI.
DI to PA.

Elantric

#28
I never said use a DI box between the Alto out and and PA input

I said

VG/GR/GP Guitar Multi-FX unit 1/4" outputs > passive DI box with ground Lift  >  XLR Input on PA / Active Powered Speaker to reduce power supply switching "hiss" noise - that can occur.

Use the Ground lift switch as needed  ( dependent  on the Venue)

jshortz

#29
I see.
Can I still come from the Alto out to the PA?
Thanks for your help.

Elantric

#30
QuoteCan I still come from the Alto out to the PA?

Yes - using an XLR cable  - but employ the Ground Lift Switch on Alto  - as needed



http://www.amazon.com/gp/product/B00356J8KE/ref=oh_aui_detailpage_o09_s00?ie=UTF8&psc=1








But I do carry one of these  - if needed


jshortz


adamlee011

I thought when I got my vg99, hey this is awesome, xlrs to record the main outs and guitar out to an aux instead of a direct box! I'm going in through the behringer x32 which let's me route an  aux to a regular channel. Wow did I get noise! I only just found the lift switch on the sub outs yesterday so I'll have to try that.

Elantric


Inside an audio isolator transformer module.

admin

#34




Elantric


Elantric


Elantric


Chrisfromiowa

Kind of tangential, but relevant to the "death capacitor" video. I know that compared to when I was playing out live in the 80's 90's the actual electrical grid had a lot more variation than it does now, between different buildings, cities, etc. I can only imagine what engineers were dealing with power wise in the late 50's and 60's.

alexmcginness

Quote from: Elantric on March 17, 2015, 10:48:23 AM
Yes - using an XLR cable  - but employ the Ground Lift Switch on Alto  - as needed



http://www.amazon.com/gp/product/B00356J8KE/ref=oh_aui_detailpage_o09_s00?ie=UTF8&psc=1








But I do carry one of these  - if needed


So, will using this direct box get rid of the digital noise that occurs when ive got the usb cable plugged into my 99 and the computer while running the editor?
VG-88V2, GR-50, GR-55, 4 X VG-99s,2 X FC-300,  2 X GP-10 AXON AX 100 MKII, FISHMAN TRIPLE PLAY,MIDX-10, MIDX-20, AVID 11 RACK, BEHRINGER FCB 1010, LIVID GUITAR WING, ROLAND US-20, 3 X GUYATONE TO-2. MARSHALL BLUESBREAKER, SERBIAN ELIMINATOR AMP. GR-33.

admin

#40
Quote from: alexmcginness on December 13, 2017, 02:05:46 PM
So, will using this direct box get rid of the digital noise that occurs when ive got the usb cable plugged into my 99 and the computer while running the editor?

Typically yes  - your mileage my vary


more details


USB Noise - audio output has enormous noise with USB cable connected
https://www.vguitarforums.com/smf/index.php?topic=367.0


GP-10 Noise floor problems
https://www.vguitarforums.com/smf/index.php?topic=12033.msg87219#msg87219

alexmcginness

#41
Quote from: admsustainiac on December 13, 2017, 02:15:17 PM
Typically yes  - your mileage my vary


more details


USB Noise - audio output has enormous noise with USB cable connected
https://www.vguitarforums.com/smf/index.php?topic=367.0


GP-10 Noise floor problems
https://www.vguitarforums.com/smf/index.php?topic=12033.msg87219#msg87219

Thanks for the response. We seem to have a problem on this thread with terminology. Hiss, hum and digital noise,are all different.
To me hiss is the sound you typically get when you turn an amp up full and you get that shhhhhhhhhhhhhhhh. Hum is different than hiss. To me its a typical ground loop or it sounds like you put your thumb on the tip of a guitar cable. The digital noise is different than the other two and occurs only when you plug the USB cable into your 99, gp10 or gr55 and hook it up to your computer. It goes away when you unplug the power supply and run on the battery if you're running the editor on a laptop.
   So would it be better to eliminate the digital noise by using a EbTech HUM-X or a direct box. I dont have a problem with hiss or hum, just that gawd awful digital noise that happens as soon as I plug in the USB cable.
VG-88V2, GR-50, GR-55, 4 X VG-99s,2 X FC-300,  2 X GP-10 AXON AX 100 MKII, FISHMAN TRIPLE PLAY,MIDX-10, MIDX-20, AVID 11 RACK, BEHRINGER FCB 1010, LIVID GUITAR WING, ROLAND US-20, 3 X GUYATONE TO-2. MARSHALL BLUESBREAKER, SERBIAN ELIMINATOR AMP. GR-33.

admin

#42
QuoteSo would it be better to eliminate the digital noise by using a EbTech HUM-X or a direct box. I dont have a problem with hiss or hum, just that gawd awful digital noise that happens as soon as I plug in the USB cable.

taming the "that gawd awful digital noise that happens as soon as I plug in the USB cable is detailed the USB Noise thread is here
https://www.vguitarforums.com/smf/index.php?topic=367.0


QuoteSo would it be better to eliminate the digital noise by using a EbTech HUM-X or a direct box. I dont have a problem with hiss or hum, just that gawd awful digital noise that happens as soon as I plug in the USB cable.

One or the other or both may be required to tame your USB Noise  -

Its typically from the modern DC-DC Switching  power supplies employed today, and why I'm an advocate for using Hi power Battery packs  = No AC Mains power  = no AC Mains Switching power supply =  no noise. 

https://www.vguitarforums.com/smf/index.php?topic=10662.0

alexmcginness

Well. the noise is gone! How did I fix it? Well, the monitors I use in my studio were Tannoy PBM8 MKII's. One of the drivers was beginning to malfunction so I bought a pair of Mackies that as you know are self powered. The Tannoys required a separate power amp. The digital noise was there because of the power amp. I decided to hook up my VG-99 and put the editor on a separate computer. I hadnt tried to use the 99 with the usb since I got off the road in November and just assumed the digital noise would still be there. To my surprise its now gone so it was the power amp that was causing the issue all along and not any grounding issues with the computers.
   It might be an idea for others to check the complete signal chain in their studios as the issue may be similar to mine.
  Thanks for your help on this.
VG-88V2, GR-50, GR-55, 4 X VG-99s,2 X FC-300,  2 X GP-10 AXON AX 100 MKII, FISHMAN TRIPLE PLAY,MIDX-10, MIDX-20, AVID 11 RACK, BEHRINGER FCB 1010, LIVID GUITAR WING, ROLAND US-20, 3 X GUYATONE TO-2. MARSHALL BLUESBREAKER, SERBIAN ELIMINATOR AMP. GR-33.

admin

Thanks for taking time to share details of your solution

admin



ttk

Hello everyone,

I'd like to have your opinion on my idea:

What if we connect the ring of our Jack plug to the earth of the extrical outlet?

Well, I did it and it suppress completely any hum.

However I just want to be sure I didn't do something wrong...

GuitarBuilder

Quote from: ttk on May 17, 2019, 07:14:18 AM
Hello everyone,

I'd like to have your opinion on my idea:

What if we connect the ring of our Jack plug to the earth of the extrical outlet?

Well, I did it and it suppress completely any hum.

However I just want to be sure I didn't do something wrong...

It means you have a good ground in your outlet!  Unfortunately not all outlets are grounded properly.  Ideally you need a single ground point for your guitar + effects + amp in order to avoid ground loops.  IMHO the best point is the amplifier input jack; again, not all amps are properly grounded, either by "design" or through lack of maintenance.
"There's no-one left alive, it must be a draw"  Peter Gabriel 1973

ttk

Quote from: GuitarBuilder on May 17, 2019, 08:19:05 AM
Unfortunately not all outlets are grounded properly.

Wait... but what does your electrical outlet look like?
Disclaimer: I live in France, and I don't remember having seen an outlet with only two poles!