Line-in recording ground hum?

Hey does anyone have any suggestions/tips for how to get rid of line-in recording ground hum on the field? I keep running into this with stereo effect pedals that I’m playing other instruments into and then going into the line in on the field. I guess I need some sort of lift box or hum eliminator?

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You could try a ground loop isolator, like this one:

I’m not convinced that’s your problem — I haven’t git a setup exactly like yours — but I’ve battled my share of hum noise over the years and these have helped in various circumstances. They’re cheap enough that I just keep a few with my cables and wire them inline when I think it might help.

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Thanks, I got a different one that didn’t do much, similar to the one you have. I tried another Behringer one, should be here soon. hopefully that solves it, but if not I’lll give this one a shot too.

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if a ground loop isolator doesn’t solve it
then most likely the root of your issue
is not ground loop hum related but something else


It’s definitely something with the pedals I’m running it into which are just before the line in, if I skip the pedals there’s no hum. They are one that is 12v dc and three that are 15v dc adapters. the 15v are the noisiest.

Everything is running off of one outlet so that’s not an issue. I ordered the one above to give it a try also. making me nuts.

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Try using an isolated power supply, like the ones from cioks or Strymon. I use a strymon suma and it’s made my chain completely silent. Absolutely recommended.


I use a Strymon Zuma as well. I can run the entire pedalboard into the OP-1f without any noise. Previously I used a One Spot (non-isolated) product which was very noisy. We also have a Fender Engine Room on the bass pedalboard, I like that isolated power supply the most as the Zuma’s IEC cable isn’t as well secured as it is on the Fender, but both power supplies work well.

This is a good idea — the isolated power supply, I mean.

@ktorunk45 you mentioned trying one ground loop isolator; if that and the Behringer don’t work, I wouldn’t buy the one I linked — they’re similar enough on the inside that if any of them work, cool, but if not, there’s likely nothing magic in any of the others.

Good luck!


Hey Thanks everyone. @KF6GPE I got the one you mentioned in the mail today and it works! really simple solution, I somehow though my problem was weirder.

I have one of the strymon clean power supplies at my guitar board, but the effects that were giving me problems were desktop oto machines running at 15v dc I believe.

Anyway putting the ground loop at the output or the input of the field seems to solve the issue either way.

Thanks again everyone.

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Well, I’ll be. That’s excellent news.

Maybe you gave me your hum. I was just setting up to use a 1010music lemondrop as an fx box (disclaimer, I work for 1010music) for my Hydrasynth desktop, and I have hum like the dickens. :slight_smile:

Time to go dig out another one of those isolators!