[With Video] - Ground / shielding hum / noise with the M1A

[Robert90]

Hi everyone,

unfortunately, for two years I have problems with noise / humming (live and during recording) which is really disturbing. I found the following quote, which describes my problem well:

If the noise goes away when you touch the output jack, then it's not ground hum. It's shielding hum.

From this thread: https://forum.lrbaggs.com/forum/pick...oise-hum-in-m1

The noise disappears when I play the guitar and touch the input at the same time. That's why in the video I touch the strings and the input at the same time. If I don't have the guitar in my hand and touch the input only, the noise doesn't disappear.

What is wrong with my M1A, how can I solve the problem?

I changed the battery twice and the cable three times. I use an Audient ID14 Interface and the D.I. Input.

Thanks for your help and many greetings from germany
Robert

Video file: https://we.tl/t-ovh2L8hnQg

[Caleb_Elling]

Hey Robert90,
The M1A is pretty well shielded, but the shielding only works when there's a good path to ground somewhere in the signal chain. It looks like you're using a USB interface into a laptop. I use a similar setup sometimes and I usually have grounding/shielding issues too. In some cases, plugging the laptop into wall-power is enough to ground the signal chain, but in other situations, or in certain rooms, I need to run another cable into an amp that's plugged into the wall in order to get a strong path to ground.

Running an output from your interface into an amp or speaker that's plugged into the wall (even if it's turned off) should ground the signal and get rid of the noise. Is that an option for you?

[Robert90]

Hi Caleb,

thank you very much for your message and your tip. I will try it out later. Live I play with a Schertler Jam 100, there the hum also occurs. I'm surprised, because the Schertler should be in any case sufficiently grounded via the power cable, right?

jam-100-bk-2.jpg jam-100-back.jpg jam-100-front.jpg

By the way, the interface is not only connected with USB, but is powered with a power supply.

Yesterday I also plugged a TC Helicon Play Acoustic (with power supply and DI function) between the guitar and the interface and the hum still occurs (at least until I touch the jack again)


8626258_800.jpg PLAY ACOUSTIC_P0DEF_Rear_XL.png

[Caleb_Elling]

Ok,
Do you have the same issue in different rooms or performance venues?

Magnetic pickups are definitely more easily subject to electromagnetic interference (noise) than other pickups, but you shouldn't be having issues as much as it sounds like you are. It sounds like there could be something wrong.

If you want to email me at [email protected]aggs.com, I will see if I can do anything to help you further.

[Robert90]

Ok,
Do you have the same issue in different rooms or performance venues?

Hi Caleb,

yes, i have these problems in different rooms and even open air. I will write to you by email, thank you!

For other people who may also read this thread: I connected the guitar twice more today to both my interface and my amp and had no more problems. I don't understand this, unfortunately. I almost would have preferred the problems to have reappeared (as they did at the gigs). Then I could at least make sure they were fixed. The only thing I've actually done differently is to use different power outlets in the wall. That would then simply mean that I was just unlucky with the power outlets at many gigs?! Or the pickup has a loose contact....

As soon as I know more, I'll post the solution here.