Noise with Computers, USB DACs, and Powerline Ethernet Kits

[Paul Birkeland]

Yes, I have two local customers here who have sub panels with neutrals bonded to the sub panel. I have spent a few years trying to convince both of them to put in isolated neutral bars, but both just say "some equipment just doesn't work in my room".

You definitely get the gold star for having your wiring checked out!

 

[Urshurak776]

Would it be advisable to just do this mod during the initial build? I just ordered my Crack.

 

[Paul Birkeland]

That is certainly an option. If you don't plan to use the Crack with a USB powered source, you may not need it at all.

 

[ryanppax]

Hey all, not sure if this is the same issue as described.
I use a Schiit Modi Multibit 2, and when I turn on my amp I hear a whiring electrical noise. If I touch the amp chassis, or screws the noise will drop. After a little bit of doing that the noise is gone.

What's going on exactly?

 

[Paul Birkeland]

If touching the chassis changes the noise, then you may have an actual grounding issue with your kit or with your home's wiring. In terms of kit issues, this could be things like having the bottom side of the chassis painted/powder coated, loose hardware, or improperly installed hardware.

For home electrical, if you do not have earthed mains, then you can get strange behavior like this.

 

[BrianJS]

Is there any reason to NOT do this, as a just because"?

 

[Paul Birkeland]

Is there any reason to NOT do this, as a just because"?

Time and money.

 

[BrianJS]

Time and money.

Time is negligible, and the diodes, 2x $0.45 = $0.90...
So basically the answer is no...

 

[Jameson]

Plus shipping!

But no.

 

[BrianJS]

So here's a thought, drop the diodes into the kit and call it a day, add $1 to kit cost(or not) if needed, in the manual state the reason for the diodes, make it an "elective" assembly step, or just an assembly step, regardless...

 

[Jameson]

We probably won't do that. The Crack is our entry level kit and we want people to build it stock first before they start tinkering. PB noted here why we don't have it built into the stock kit:

I sure do like having the safety ground connected with a solid piece of wire when a component is being powered on for the first time!

It's also not necessary for many people. This is an easy enough mod for folks to do on their own without requiring an update to the manuals.

 

[BrianJS]

The "I sure do like having the safety ground connected with a solid piece of wire when a component is being powered on for the first time!" doesn't hold water for this simple reason...

A diode will fail open or short in a predictable way. A wire will glow red and burn if something goes catastrophically wrong.
A diode clamps instantly.A wire heats, expands, and only then fails.

If anything, the diode is more predictable under fault conditions.

This is basic electronics, not rocket science.

 

[Paul Birkeland]

The "I sure do like having the safety ground connected with a solid piece of wire when a component is being powered on for the first time!" doesn't hold water for this simple reason...

A diode will fail open or short in a predictable way. A wire will glow red and burn if something goes catastrophically wrong.
A diode clamps instantly.A wire heats, expands, and only then fails.

If anything, the diode is more predictable under fault conditions.

This is basic electronics, not rocket science.

The wire will handle enough current to trip the breaker in your AC mains panel. UF4007 diodes will handle enough peak current to get the job done, but just barely.