Difference between hum eliminator and ground loop switch on DI box

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Jmaster_17
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Difference between hum eliminator and ground loop switch on DI box

Post by Jmaster_17 » Fri Sep 22, 2023 5:28 pm

I've been having some issues with hum and buzz in my recordings lately. it doesn't occur with clean tones but mid-high gain stuff is nearly unusable. Someone suggested that I use the ebtech hum eliminator to remedy this. I did a small amount of research and it looks like what the ebtech will do is convert the unbalanced signal to a balanced signal, isolate the left and right channels, and eliminate ground loops (if I am wrong please correct me as electronics are a bit of a mystery to me)

I was wondering if it would be similar to just using DI boxes and flipping the ground loop switch. I’m using IRs to record atm and just going stereo into a Scarlett 2i2 gen 3 with no di. So to save me some money could I just use DI's instead of purchasing the ebtech?

Or if you guys have any other solutions that are relatively inexpensive I’m open as well.

I don’t check this forum super often so I may or may not respond but any feedback is appreciated

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Re: Difference between hum eliminator and ground loop switch on DI box

Post by øøøøøøø » Sat Sep 23, 2023 6:11 am

If it doesn’t occur with clean tones, the issue is before whatever the distorting device is

To address the issue, we’ve got to figure out the source—if it’s single coil hum that gets worse with distortion, then isolating via transformer or lifting ground obviously won’t help (just for one example)

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Re: Difference between hum eliminator and ground loop switch on DI box

Post by marqueemoon » Sat Sep 23, 2023 8:13 am

What is the signal path here exactly, and where is the overdrive/distortion being added (pedals, a real amp, hardware modeler, in-the-box amp sim, etc…)?

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Re: Difference between hum eliminator and ground loop switch on DI box

Post by Jmaster_17 » Sun Sep 24, 2023 7:20 am

marqueemoon wrote:
Sat Sep 23, 2023 8:13 am
What is the signal path here exactly, and where is the overdrive/distortion being added (pedals, a real amp, hardware modeler, in-the-box amp sim, etc…)?
signal chain is quite complicated. I change it a lot but generally it goes

RC-Booster > Polytune Mini Noir > POG2 > PitchFork (I have since removed this as it is broken but the buzzing persisted) > SP Compressor > JHS Emperor V2 > J Rockett Silver Archer > Strymon Sunset > Xotic SL Drive > EHX Mainframe > Strymon Iridium > (signal is now stereo) > Bigsky > Timeline > (Signal output is uneven in the left and right so I go out of the right channel with a passive attenuator, the EHX Signal Pad) > Ditto Stereo Looper > Scarlett 2i2 Gen 3 > laptop

I also use an expression pedal with the pitch fork and the mainframe. not at the same time though. I’m using the dunlop Volume X mini for expression ONLY so nothing is plugged into the audio inputs or outputs. I mention this because for whatever reason when I had the TRS cable plugged into the EXP jack on the Volume X and the other side was not plugged in, the buzzing was worse and then when I plugged it into the Mainframe EXP jack it got slightly better. The pedal, I am pretty sure was in bypass. Anyways. Rabbit trail

The distortion is not from any of the drive pedals. I just cranked the gain on the Iridium. the buzzing is heard from like 2-3 o clock all the way to max gain. compressor on or off makes some difference.

I don’t know if this is helpful but sometimes if I’m not wearing shoes or socks and I touch one of the pedals with my foot the buzzing also decreases

I have isolated the Iridium and it does help some but still not to the degree I would like for a recording. Maybe I’m just too picky?

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Re: Difference between hum eliminator and ground loop switch on DI box

Post by marqueemoon » Sun Sep 24, 2023 8:43 am

It does seem there’s a grounding-related aspect to the noise.

I assume with the big Strymon pedals you’re using a good power supply?

Is everything connected to the same circuit (pedals,laptop, interface, etc…)?

Have you been able to pinpoint where the level mismatch between channels is occurring? That doesn’t seem right to me, and if you’re having to attenuate the louder channel and raise the level of both later that’s probably not helping.

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Re: Difference between hum eliminator and ground loop switch on DI box

Post by øøøøøøø » Sun Sep 24, 2023 5:21 pm

In a situation like this the very best troubleshooting procedure is to remove all elements besides the guitar and interface and then add them back in one at a time

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Re: Difference between hum eliminator and ground loop switch on DI box

Post by Jmaster_17 » Sun Sep 24, 2023 7:52 pm

marqueemoon wrote:
Sun Sep 24, 2023 8:43 am
It does seem there’s a grounding-related aspect to the noise.

I assume with the big Strymon pedals you’re using a good power supply?

Is everything connected to the same circuit (pedals,laptop, interface, etc…)?

Have you been able to pinpoint where the level mismatch between channels is occurring? That doesn’t seem right to me, and if you’re having to attenuate the louder channel and raise the level of both later that’s probably not helping.
yeah I went through my stereo chain (the order listed in my earlier post) and tried to find it. I used my DAW to measure signal levels and it seemed that both the Bigsky and Timeline had a signal difference and the iridium did not.

As far as power, I’m using the MXR ISO Brick for everything and then I mounted a power strip with underneath as well which I plug the power supplies that came with the Strymons

laptop I don’t use plugged into power it's just going off of battery and the Scarlett 2i2 is using the laptop battery for power

so all that is plugged into the wall is the power strip mounted underneath with the power supplies and the ISO brick plugged into that

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Re: Difference between hum eliminator and ground loop switch on DI box

Post by Jmaster_17 » Sun Sep 24, 2023 7:54 pm

øøøøøøø wrote:
Sun Sep 24, 2023 5:21 pm
In a situation like this the very best troubleshooting procedure is to remove all elements besides the guitar and interface and then add them back in one at a time
yeah I haven't done that yet. need a time when I have a day to tear it all apart and put it back one by one lol

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Re: Difference between hum eliminator and ground loop switch on DI box

Post by øøøøøøø » Mon Sep 25, 2023 7:31 am

Sometimes all it takes is one weird cable, or one faulty output on a power supply brick, etc…

And if you’re not systematic, you’ll frustrate the hell out of yourself!

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Re: Difference between hum eliminator and ground loop switch on DI box

Post by cestlamort » Wed Sep 27, 2023 3:25 pm

øøøøøøø wrote:
Mon Sep 25, 2023 7:31 am
Sometimes all it takes is one weird cable, or one faulty output on a power supply brick, etc…

And if you’re not systematic, you’ll frustrate the hell out of yourself!
So much truth there (I spent way too long tracking down a loose George L cable connection earlier today)

You can also fudge things by patching in halfway: if the noise is gone, then it’s in the front half, if not then the issue is in the second half (or systemic). The iridium has headphones out so that is a snapshot of the signal chain to that point. Etc. etc. I’ve found it helpful to divide things into regions and then drill down.

As Brad said, the best practice is to tear it all down and slowly add stuff back.

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