Ground Loop Isolation Options

grimmace19

Alright folks, I know ground loops have been beaten like a dead horse but I recently tried something new and was wondering if anyone had attempted the same or has other ideas on how to get mine to stop.

So a few months back I added a gfa-5802 into my rig to run my fronts. When I did this, for the first time ever I had a ground loop buzz coming from my mains. The amp is plugged straight into the wall using a signal magic power cable. I still have my gfa-7500 running my center and surrounds which is plugged into my monster power center and I do not have a hum coming from my other three speakers. In my opinion, it seems as if the only option is that it's coming from the 5802... is there a chance that this is coming from something else other than a ground loop? Bad caps ect? I can't hear the hum when any music at any volume is coming out and when the system is quiet, you have to have your ear about a foot from the tweeter to hear it. I bought a HumX from ebtech the other day in hopes it would fix my issue http://www.amazon.com/Ebtech-Hum-Voltage-Filter/dp/B0002E4YI8/ref=sr_1_1?ie=UTF8&qid=1350567240&sr=8-1&keywords=ebtech+hum+x with no luck. Has anyone tried and had success with the HumX before? Based on the solid reviews I think it's likely a good product in a lot of applications apparently just not mine. Should I try the humX on some other gear in my system to try and kill the loop? Its only able to have 6 amps run through it so I assume I wouldn't be able to plug the entire monster power center into it (ps3, 65 inch plasma, gfa-7500, squeezebox, hegel dac, dtv box) are all running through it.

Thoughts, opinions, anything helpful on how the hell I can get this to stop?

Thanks

tonyb

Did ya try a 2 buck cheater plug on the amp ?

grimmace19

I have not tried one yet... are you suggesting this as a temporary test to see if I can get rid of it or is it a bunch of hoopla to think it's dangerous?

GlennDog

tonyb wrote: »

Did ya try a 2 buck cheater plug on the amp ?

Cheater plug? Please clarify, TY Tony

G

FTGV

Does the hum still exist without the preamp connected to the inputs of the amp?If so the problem is within the amp, otherwise your likely dealing with a ground loop.As for the cheater plug to eliminate the chassis ground it should in my opinion be used only as an experimental short term solution only.That safety ground is there for a reason.
As for the Humx device I have no experience with it but if it is what I think it is internally it may well solve the issue but it is rather pricey consisidering the simplicity.It can be DIY'd for those so incline for a fraction of that.

Thorton

When I added my Parasound, I had the ground loop problem. I read through numerous threads and did the detective work to notice the problem was only associated with the amp. The HumX completed eliminated the buzz coming through the speakers. It's been working fine ever since. Looks like you may have to do a little more detective work.

grimmace19

Thanks for the input so far. I tried the amp without it hooked into the pre and guess what... the hum remains! So basically it's an amp problem. What could cause this? The noise comes from the tweeters and is a low static/hum that I can hear from about about a foot away.

treitz3

http://en.wikipedia.org/wiki/Cheater_plug

grimmace19

^Thanks, but I understand the cheater plug. It seems as if it must be an issue with my amp as it still has the hum when it's not connected to the pre.

treitz3

OK, fair enough. The thing is, a "hum" can not come from a tweeter. A hum comes from a woofer and is usually associated with 60Hz. That's a hum. Out of the tweeter, one would normally notice static. Before we proceed any further, could you please clarify exactly what it is you are hearing and from what drivers the unwanted artifacts are coming from? Not confronting, just trying to assist in getting this issue resolved. Have you tried the cheater plug yet or tried flipping the plug's polarity?

Tom

grimmace19

I suppose it's more of a static. It does come out of the tweeter. Nothing from any of the 4 drivers between the two speakers. My 9's and lsic are dead silent when my other amp is turned on so it must be an issue with the 5802. It's plugged directly into the wall with a signal magic power cable. I haven't tried the cheater plug yet, and flipping polarity... does that mean turning the plug upside down essentially so it goes into the plug the other way?

treitz3

Yes, sir. Try both and then please get back to us with the results.

Tom

FTGV

grimmace19 wrote: »

The noise comes from the tweeters and is a low static/hum that I can hear from about about a foot away.

Is this the same noise and at the same level your hearing with the preamp connected?(no ground loop can exist with pre disconnected) Well if that being the case if you need to be with in a foot to hear it that is likely just the intrinsic noise of the amplifer.If it were a ground loop it would be a very audible hum and apparent at much greater distance.

cconklin1

check your cable feed...

SugarmillMan

GlennDog wrote: »

Cheater plug? Please clarify, TY Tony

G

He's talking about a two pronged plug adapter, without a ground prong.

RamZet

I will use two items to remove Hums from an install. First item I try is a Mobile Spec MS-104 Ground Loop Isolator 20Amps RCA Plugs. If that doesnt do the trick or makes it worse I will try a Audio Systems Group Ac Ground Lift Adapter. One of the two or the two together work every time. Another cool option some amps and stereo equipment has are built in ground lift switches in the back.
Another great item to add to any system is a Panamax (or other name brand) line conditioner. They are great at cleaning up noise. I like the Panamax 4300.

ground loop https://www.google.com/shopping/product/11587398529593101263?q=ground%20loop%20isolator&hl=en&safe=off&bav=on.2,or.r_gc.r_pw.r_cp.r_qf.&fp=14445ba3dd332fc9&bpcl=38625945&biw=1309&bih=666&tch=1&ech=1&psi=E-aoUKO3G66u0AHAt4HYBg.1353246228742.3&sa=X&ei=GOaoUMnjM4fC0AHivYHoDw&ved=0CIoBEPMCMAg

ground lift http://www.opentip.com/Electronics/Audio-Systems-Group-Ac-Ground-Lift-Adapter-p-1412713.html?gclid=CLmwwavT2LMCFY-d4AodvGMAIw

Panamax4300 http://www.amazon.com/Panamax-M4300-PM-Outlet-Clean-Power/dp/B000SXWGDI

Another thing that I see that can cause a hum is a ungrounded cable tv distribution. Always run a ground from the splitter or ground block to the house ground (or a water pipe).