Ground Noise Playing Through MacBook/Focusrite/Monitors

[Jabberwocky]

Class I and Class II Equipment Explained

More than you want to know...

[Jabberwocky]

At your own risk: you see the Double Square symbol on the back panel of the Eris 3.5? Attach a yellow/green wire to the closest screw to the symbol that mounts the 2-pin power socket to the back panel. Unscrew it a little and screw the ground wire down. Attach the other end to the ground tab of the Schuko wall socket with an alligator clip or some such. I assume that you know what that ground tab is.

As a precaution, wear thick rubber gloves and rubber boots, standing a thick rubber mat on dry ground when you try this.

Not responsible for any electrical shock or death arising from following dumbass instructions garnered from an internet forum.

Take good care, Stefan. Common sense and all that. Auf Wiederhören.

[Stefan Eff]

You have your own reasons that I won’t question. My power strip has switched outlets. Even if you do not charge up your Macbook and leave it plugged into the power supply, connected to your mains but not switched on your system is grounded by the ground pin. You need to pay about €20 for that official Apple extension power cord or €3 for a China knockoff. This is the simplest, direct and most cost effective solution.

If you know where the chassis ground screw is on your Presonus Eris 3.5 monitors you could run a ground wire from the chassis ground screw to the ground tab of a Schuko wall mains socket. Do that at your own risk.

I‘ve got a Macbook Air M4, I doubt there is a different power cable available. My next try will be a DI Box, curious if that may help.
Ha, and no, I don‘t fool around with high voltage electricity ;-)

[Jabberwocky]

All Macbooks power bricks have a pin adapter that slides off; this enables Apple to supply different pin configurations for different parts of the world with the same power brick. Your Macbook M4 Air uses a 70W power brick. Push up on the pins and the adapter slides off. You replace it with this:

I‘ve got a Macbook Air M4, I doubt there is a different power cable available. My next try will be a DI Box, curious if that may help.
Ha, and no, I don‘t fool around with high voltage electricity ;-)

[Jabberwocky]

The part with the 2 power pins slides off when you push up on it. All Macbook power bricks have this detachable part. The extension power cord slots in in its place.

[Stefan Eff]

I‘ve tried a passive DI-Box with a „ground lift“: the noise is completely gone and so is my tone

Sounds weak, sterile and quiet.
Maybe it‘s the wrong cable? Since I need the usual TLS cable for the Scarlett (the DI‘s got an XLR out) I used an old microphone cable for a first try: XLR from DI and TLS in Scarlett.
So far unusable

[GuyBoden]

I‘ve tried a passive DI-Box with a „ground lift“: the noise is completely gone and so is my tone

Sounds weak, sterile and quiet.
Maybe it‘s the wrong cable? Since I need the usual TLS cable for the Scarlett (the DI‘s got an XLR out) I used an old microphone cable for a first try: XLR from DI and TLS in Scarlett.
So far unusable

Yes, I agree, to get a good sound from a passive DI box, it needs to have a good transformer and they are usually expensive. I have tried many inexpensive passive DI boxes, they're on my shelf gathering dust.

[Stefan Eff]

Yes, I agree, to get a good sound from a passive DI box, it needs to have a good transformer and they are usually expensive. I have tried many inexpensive passive DI boxes, they're on my shelf gathering dust.

Yes, but I guess it was my mistake- the signal from the DI-Box to the interface is too weak (Microphone), that‘s why the sound is killed. But the Noise was gone!

I‘ll try a 2-channel hum suppressor between interface and speakers: curious if that will finally solve the problem!

[SOLR]

Yes, but I guess it was my mistake- the signal from the DI-Box to the interface is too weak (Microphone), that‘s why the sound is killed. But the Noise was gone!

I‘ll try a 2-channel hum suppressor between interface and speakers: curious if that will finally solve the problem!

Silly question but, Does anything sound clean in the speakers?

Your monitors allow for a phone or mac (w 1/8") to connect directly, have you tried this?

S

[Stefan Eff]

Silly question but, Does anything sound clean in the speakers?

Your monitors allow for a phone or mac (w 1/8") to connect directly, have you tried this?

S

Yes, they work perfect. It is definitely a ground problem.

[Stefan Eff]

The part with the 2 power pins slides off when you push up on it. All Macbook power bricks have this detachable part. The extension power cord slots in in its place.

Thanks man, problem solved!
Totally silent.
I didn't really want to leave the MacBook plugged in all the time, but there's an app that pre-selects the charging current (e.g. at 75%), which is certainly better for the battery.
Thanks again!

[SOLR]

Thanks man, problem solved!
Totally silent.
I didn't really want to leave the MacBook plugged in all the time, but there's an app that pre-selects the charging current (e.g. at 75%), which is certainly better for the battery.
Thanks again!

How did you solve it?

Might help others......

S

[Stefan Eff]

How did you solve it?

Might help others......

S

Grounded power cord on the Macbook.