# Ground Loop Isolation Adaptors/Transformers - All made equal?



## robojack

I was looking into devices that can help reduce ground hum, and since cheater plugs are illegal in Canada (and thus impossible to buy here), I'm looking into alternatives.

 I saw at my local Radio Shack a Ground Loop Isolator adaptor (RadioShack.com - Car: Accessories: Car A/V accessories: Ground Loop Isolator). Any idea if this is enough, or will a more expensive one do a better job? Most importantly, will ground loop isolator negatively impact my sound, other than just removing the ground hum?


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## Andrew_WOT

This one would be a much better quality than Radioshack, I had one, the build is top notch.
Amazon.com: Ground Loop Isolator: Electronics

 Or you may try different approach and get Amazon.com: Ebtech Hum X Voltage Hum Filter: Musical Instruments
 it is not in the signal path and should not have any impact on the sound, but it might not be 100% effective though. Wish someone who tried one can chime in.


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## DynaFreq

So I really wanna build my own ground loop isolator.....any tips?

 Also I have a grounding problem with my laptop [old Dell Inspiron 6000]. It is the only Laptop that I have used that comes with a three prong AC adapter. Any time I have my laptop plugged on the same circuit as any of my audio gear I get buzz, even if the laptop is not hooked up to my gear. It's far below the noise floor in my house, but it still exists.


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## Lucabeer

Quote:


  Originally Posted by *Andrew_WOT* /img/forum/go_quote.gif 
_This one would be a much better quality than Radioshack, I had one, the build is top notch.
Amazon.com: Ground Loop Isolator: Electronics_

 

Ditto! I have this one by Xitel too, and I feel it's truly a quality product: very effective, and to my ears it sounds "transparent".


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## Andrew_WOT

Quote:


  Originally Posted by *Andrew_WOT* /img/forum/go_quote.gif 
_Or you may try different approach and get Amazon.com: Ebtech Hum X Voltage Hum Filter: Musical Instruments
 it is not in the signal path and should not have any impact on the sound, but it might not be 100% effective though. Wish someone who tried one can chime in._

 

Switched to HumX recently and it is as effective as cheater plugs, highly recommend.


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## msooffutt

The radioshack cable works great. I've owned it for 5 years now. I bought the monster cable version, which looked like it was better quality, and ended up throwing away the monster version and went back to the radioshack cable. The Monster version didn't get rid of all the noise like the radio shack did. Monster cables are crap imo.


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## Uncle Erik

Quote:


  Originally Posted by *robojack* /img/forum/go_quote.gif 
_...since cheater plugs are illegal in Canada (and thus impossible to buy here), I'm looking into alternatives._

 

You could clip off the ground prong on your plug or on a cheap extension cord.

 I generally don't recommend defeating grounding on equipment, but you might want to give it a try first to see if it makes a difference.


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## nick n

thread ressurection!
  I went and picked up one of the Radio Shack versions. ( the Source here in Canada is our new Radio Shack )  Exactly like the linked one and_* this thing is picking up the local radio station*_!!!!! what a JOKE. Very low but I can hear what they are saying. I certainly didn't expect that. Even my Audioengine A2 's do it very faintly almost imperceptibly from time to time although rare.
   
  Whats the issue?
  ----Do I go and replace all the rca's with shielded ones, as well as the speaker cable that joins the A2 's together with shielded speaker wire?
   ----Higher OHM rca cables?
  Thats about all I can think of. It makes the original faint hum sound crystal clear in comparison.
  I tried reversing it as if that would make a difference. Nothing. I can try to place it more towards the computer but that is probably a waste of calories as well.
  ----Maybe I should look into replacing the power caps? It may be integral to the older tube amp rather than what I thought was a ground loop, although the hum does a sudden increase when the music player is sitting in a paused state ( this is probably the A2's low power function kicking in-- NOPE does it unhooked too ) When the music player stops the hum increases to irritating levels.
  I will try to remove the splitter from the motherboard and unhook the A2's.Nope
  See if I can locate an extension cord and try another fused zone in the apartment.
  By the way the tube amp is a 2 prong plug end...
  Options here?
   
  Thanks this problem now  irritates me more than before.
  
  Quote: 





msooffutt said:


> The radioshack cable works great. I've owned it for 5 years now. I bought the monster cable version, which looked like it was better quality, and ended up throwing away the monster version and went back to the radioshack cable. The Monster version didn't get rid of all the noise like the radio shack did. Monster cables are crap imo.


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## Steve Eddy

Can you describe your system/setup and exactly what your problems are?
   
  Thanks.
   
  se


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## nick n

Setup is as follows
  Computer is an AM3 Gigabyte 785GMT-UD2H ( low emi ) with onboard audio ALC889A chipset. No front panel audio hooked up at all. Plugged into powerbar. Seetings in Ubuntu 9.10 audio options are set at ANALOG STEREO DUPLEX. ( should it be just ANALOG STEREO?? )
  Computer powersupply is a passive FSP ZEN 400.
  No wireless phones or routers except maybe somehwere else in the apartment building. None above me she is about 90 years old lol.
   
  Audio out on motherboard has a 3.5mm splitter running to Audioengine A2 speakers ( self powered plugged into same powerbar ).The A2's have a small run of 14 gauge speaker wire connecting them to each other.
  Other half of splitter has a 3.5mm adapter with unshielded elcheapo run-of-the-mill rca's on other end to a 1959-61 Heathkit AA-151 tube amp' AUX input terminals. No leaky or bulged caps- all appear in above average shape. Mint insides with brand new matched quad of el84 jj tubes. Has a pre and amp for each channel in it.
  This amp is plugged into a different wall outlet but on same fused zone of room wiring, uses a 2 prong powercord end.
   
  The tube amp is a dedicated headphone amp with nothing else hooked to it. Speaker terminals set to 8 ohm out of the 4,8, and 16 ohm options ( no headphone jack on the tube amp ) run about 20 feet of 14 gauge speaker wires to a custom headphone jack with LEFT and RIGHT positive wires having a 100 ohm metal oxide resistor on each. Also from same speaker outs runs about 20 feet of 14 gauge speaker wires to a Stax transformer box ( plugged into same wall outlet the powerbar is ) for SR5's and/or AT-705 electret box.
   
  What happens is that  from time to time there is a very faint radio station coming through my A2's when they are on with no music playing. Rarely.
   
  When the tube amp is on there is a small hum equally in both channels of ( with the headphones easier to notice )
  When I stop playing music the hum is still small, but then all of a sudden kicks up a fair bit I think after the audio player stops for a few seconds.
   I had thought it was a ground loop so picked up a relatively cheap* inline rca groundloop isolator adapter*. When that is hooked up, I get the same local radio station except at _audible_ levels! and the hum is a fair bit louder as well. So that's going back to the store.
  There is no hum when I just use the A2's by themselves with the tube amp off.
   
   
  One thing in particular is that my cpu heatsink is massive and external to the case. Passive. Pictures here.
http://www.head-fi.org/forum/thread/397869/pictures-of-your-computer-rigs-post-them-here/4125#post_7503438
  I did make a temporary stainless cage for it temporarily in case that was acting like an antenna but no difference.
   
  I will switch the audio setting to simple Analogue Stereo, try a different extension cord to a separate wall outlet area, and try these new expensive shielded rca cables to the amp.
  Other than that , I may need a recap in the transformer/power areas of the amp, swap all the speaker wire to shielded ( **** that sounds expensive )
  Also going to try and rearrange wiring to avoid crossing power cables with speaker wires etc. That should be fun
   
   
  Open to cable ideas, using digital out to a DAC etc.
   
  Is that enough information? I feel like I am droning on.


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## Steve Eddy

What happens if you remove the splitter and go straight into the amp?
   
  se


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## nick n

I rerouted ALL the power cords away from the speaker runs, am using an actual shielded 3.5 to rca to the amp, but the hum is still there. Also tried it solo without the splitter. It HAS to be the transformer hum internally. For headphones i'm using both the AT electrets and the AKG dynamics both through different speaker wiring,  but both sourced off the speaker terminals and it comes up the same. Seems a bit tamer and I could not replicate the sudden increase in hum when paused so that's a good thing.
   
  Oh well. I thought that it was odd though that the radio came on earlier when using the Ground Loop Adapter!
  No sign of that radio signal with the Ground Loop Adapter off though. 
   
  A few more things to try if I can find my extension cord. I may live with it  for now.


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## Steve Eddy

Ok, another question.
   
  Do you have a soldering iron?
   
  I'm curious what you get if you make a pair of shorting plugs and plug them into the AUX input on the amp and see what sort of noise and whatnot you hear.
   
  If you're still getting noise after that, then it's definitely something internal to the amplifier.
   
  se


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## nick n

Yes I have an iron and will see if I can get around to making a set of plugs today. Good idea. Thanks.
   
  It's the amp itself. Probably transformer hum. Not as bad as before but still sort of there. Thanks for the ideas!


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