Ground loop hum - 20 amp circuits

[Grasshopper]

I know this has been discussed before, and I’ve read many of the threads on the subject.

I’m getting a nasty buzz/hum, which is keeping me from enjoying my new preamp.

I’ll be the first to admit, I don’t know much about electricity.

When we finished our basement, I had the electrician add like 10 dedicated 20 amp circuits.

(I did not specify that the audio equipment all be on the same phase, so my electrician said he could come in early January and rearrange the subpanel).

Everything I read about fixing ground loop hum says to run the whole system off one outlet, or daisy chain the ground.

As for the advice to run everything off one outlet- what is the point to having multiple dedicated circuits if using more than one outlet introduces hum?

I’m very confused-

(Also I cannot picture the daisy chain “bonded” method- if anyone has pictures I’d appreciated it).

Please help! I’m running on 2 days now of rearranging the system to no avail-

[GeAllan70]

this...



https://www.amazon.ca/Morley-Hum-Ext.../dp/B08NPY6CBN

[SCAudiophile]

What components, when powered on, cause the hum, i.e. when you start turning your system on one item at a time, when does the hum start?

[FreddieFerric]

I've had a ground loop problem in the past, but the culprit turned out to be a defective power supply on a phono preamp.

I would not assume the problem is with the wall outlets. The first order of business is to strip everything down and start from scratch. Adding one component at a time until you find out what is causing it.

If you have a spare preamp, or could borrow one short term that might help as well.

FWIW, those ground loop eliminators usually do not work in my limited experience.

If your power cords have removable ground pins you might try that as well.

Finding the culprit is a process of elimination. You may need to go as far as run an extension cord from another part of the house to check if the problem still persists.

Try to be patient and calm. Ground loops are one of the most frustrating problems audio enthusiast can face. I hate them. (Not audio enthusiasts, but ground loops)

[SCAudiophile]

Originally Posted by FreddieFerric

I've had a ground loop problem in the past, but the culprit turned out to be a defective power supply on a phono preamp.

I would not assume the problem is with the wall outlets. The first order of business is to strip everything down and start from scratch. Adding one component at a time until you find out what is causing it.

If you have a spare preamp, or could borrow one short term that might help as well.

FWIW, those ground loop eliminators usually do not work in my limited experience.

If your power cords have removable ground pins you might try that as well.

Finding the culprit is a process of elimination. You may need to go as far as run an extension cord from another part of the house to check if the problem still persists.

Try to be patient and calm. Ground loops are one of the most frustrating problems audio enthusiast can face. I hate them. (Not audio enthusiasts, but ground loops)

Yes definitely,....further, those hum eliminators are usually marked with a max Amp rating as is the case in the ad for the one below that precludes using it with most audio gear in the first place.

If he has RCAs as well, try XLRs or at least another pair of RCAs, one verified to be built with full ground and conductor compliment. I've seen this type of problem come up with interconnects where the ground connection on the 1 connector came loose internally due to iffy terminator, and also where the pair was not built properly in the first place.

[Masterlu]

Jason… I will call you later; I have all of the answers.

[sleepysurf]

If this is also a home theater setup with coax cable connection, disconnect that first. That is a frequent culprit, and can usually be eliminated by something like this... https://www.amazon.com/TII-220-Groun.../dp/B0070Q6URO

[johnau]

+1 for sleepysurf suggestion above, that was one issue I faced/fixed. Also I had plugged in one of those multi-usb charger hubs in the same circuit and that added a ton of buzz. Removing it fixed the issue.

[Grasshopper]

Thanks all!

@masterlu is the man! He took time out of his busy day and got me squared away- for now, the hum is gone and I’m listening to music again.

[cdobson]

Awesome [emoji122] and not surprised!!