DIY Active Ground Box

I recently received a custom cable that has three loop-ground spades that are linked to the cable's shield. The cable was originally designed for phonograph use, but my customized version is being used in a digital to analog function. The manufacturer left the loop-spades in. The manufacturer said I could just use electric tape to "cap them off."   The ground cables are not 100% necessary in this application. However, they are an exposed conductor. I know that I can enhance their performance by treating them as a floating shield by using an active ground.

I was thinking it would be cheaper and more practical to make my own. Does anyone have experience doing this? If so, can you share your design ideas?

The concept I have seen and want to build on, is making a wooden box that is coated internally with copper plates. Then use an IEC C14 socket to attach the ground lead to the copper plates via a solid copper cable.  Then create a simple plug using a NEMA 1-15 connector where only the ground lead is connected.

Then insert banana plug sockets that also attach to the copper plates via a copper cable. Then connect the spades to the banana plug outlets.

Once this contraption is plugged into the wall socket, it should effectively attach to the house's ground.



I don't see the point of grounding one component to the copper filled box. The concept of the grounding boxes on the market is to create a common ground for all the components. All are wired to the box which creates a star-ground; they will have the same ground potential. This box is then plugged into the mains.

I like that you are thinking this way to begin with. It may not be the best approach, yet there is merit in the thinking. I agree with the previous poster as to what might be tried out. Even in a star grounding scheme, it wouldn't hurt to ground components one by one. If somehow there is trouble because of it, you will have a head start on the direction to look.


How do I get the three ground spades connected to common ground?  The wall plug is too far away.  I need a way to extend their conductance to ground.  I cannot use any screws on the audio equipment as the screws are recessed into the plate, so having a thick spade connected to it will compromise the construction.



I am using Shunyata's Venom V16 power distributor, which is grounded to the wall.  Even if I use that, I still need to find a way to connect the spades.  They're about 6 to 7 inches in length. It just seemed practical to have a box to connect all three and then connect that to the common ground.

It may be simpler to just plug all the equipment into the same wall outlets, and then you would have a better common ground.  Then you could add your DIY supplemental ground after that and not worry about adding a ground loop or causing a safety hazard.  If you really want to hotrod your setup plug everything into a good power conditioner and that will give you a much superior common ground plus power conditioning.


I guess I should disclose my system.

The socket is Audioquest NRG Edison with a PSAudio Noise Harvester in one socket, the other is the Shunyata Research Venom V16 power conditioner using their Reference Delta V2 XC high current cable. 

The problem is the custom Synergistic Research Atmosphere Alive Phono cable.  I needed a cable that went from 3.5 Stereo Mini Pin to Left/Right RCA.  When I ordered the Foundation version, they left off the ground loops.  For some reason, they decided to leave the ground loops on. Three of them.  One for the 3.5 mini pin and one each to the RCA connectors.  They're connected to the braided shield, so really, it has a floating shield. 

I know Synergistic sells a "ground block" and other companies sell "ground block" products, but I was hoping to DIY a version. I cannot simply take these 6 inch cables with an open spade and just magically connect them to the wall socket or even the Venom V16.  They need a way to get there.

My idea is, any signals the shield captures, would drain into the box and the box drains into the actual shared ground as all the rest of the equipment. :)

Does that make a little more sense? :)

@guakus Something I’m not clear on, ground wires on one end, what will be the termination on the source end of this cable?

Wouldn’t the ground wires attach to the grounding box and then go to the Shunyata?



Remember, this was supposed to be a phono cable and those have a ground, typically. Due to the type of customization, Synergistic suggested the Phono cable as the base.

One end is stereo 3.5 stereo mini pin; like a headphone jack. The other end is two RCA, one left channel and one right channel. Synergistic left in the ground wires, as if it was still going to be a phono cable. I can't stand the fact that there are three wires with silver spades just hanging free. :(

This cable comes out of a USB DAC and plugs into a pair of powered speakers. Audioengine HD6.

Just cut the ends off the offending wire(s).  Problem solved.  Too much effort and no real improvement if you go through all this nonsense.


Cutting the cables would achieve the exact same thing as not cutting them...except that by not cutting them, I have an opportunity to do something with them. Also, by cutting them, one has no way to address any noise issue having a bare wire exposed.

I understand people's skepticism about stuff like this, but if I break it down to the most basic electronics concept, then it makes sense.

There is a positive conductor and a negative conductor and a braided shield. Normally, the shield just loops into itself inside the cable. Whatever signals it captures or picks up, just stays netted in the shield. By having an external conductor for the shield, then any signals it picks up can now be bled off and away.  I don't see the harm in having it direct somewhere else safely.

Point is, it won't hurt to try it.


I did it and it works. 

For about $87.00 USD I bought all the materials and put it together.

A small 6 x 6 inch wooden box.
A package of two 6 x 6 copper plates
A coil of bare copper wire.
A package of four banana plug binding posts.
A male, all copper, NEMA 5-15 amp male plug.
A coil of shielded, tinned-copper wire.
A coil of copper tape.
A pack of four banana plugs.
A package of Hawaiian Charcoal Salt.

Things added that I didn't buy: Tree charcoal, and large crystal rock salt for use in making ice cream.

I plated the bottom and all four side walls of the box in copper plates. I used a "U" shaped copper plate and attached it to the main banana biding post. Then attached a line of bare copper to that same binding post and attached it to the bottom copper plate. The lid is where I attached the remaining banana plug biding posts.  Each lid post has a line of bare copper wire that is attached to the bottom copper plate. I then wrapped some copper tape around all three lid binding posts. I filled the box with a mixture of tree charcoal, Hawaiian charcoal salt, rock salt, copper filings, and some local dirt.

Then I made a ground plug using the shielded tinned-copper wire to attach to the ground spike on the NEMA plug. I taped off the positive/negative posts inside with electric tape. On the other end, I added a banana plug.

I used a voltmeter and tested to make sure each post conducted all the way to the ground cable.

Finally, I connected the three ground spades and then plugged the ground cable to the wall socket.

I also tested with the voltmeter to determine it was working and was conducting signal. Everything worked.

As for sound quality, I am going to let it break in for a week or so before I determine if it alters the sound in anyway.

I believe you don't need a box if you are connecting the signal grounds to an outlet ground.

If you are using a box by itself to dissipate EMI then make an antenna in a V shape inside the box with a simple banana plug. I fill my boxes with quartz crystals, Rochelle salts, and tourmaline. I use wooden boxes and also have purchased some cylindrical cardboard tubes for the passive devices.

So I use both methods and for the outlet I made a one wire plug for the ground only and a banana jack sticking out the back to make connections from the signal grounds to the plug.

I also use the Ground Master for power grounds onto the Puritan and separate ground rod. I may make a parallel run with another groundmaster for the signal grounds.

I wanted a way to ground the loop spades the cable have. Just letting them sit there dangling, or taping them off or cutting them off was undesirable.

I have enough material to make another one.  I think I will try your backfill recipe. :)


The idea isn't about blocking EMI.  It's about safely dissipating all collected or excess electrical signal that enters, propagates or is erroneous.

Ok, so the copper plates are simulating the copper grid that is usually created in a house or building ground. It's a highly conductive plane that attracts the electric signal and keeps it trapped there until it dissipates.


Well I have a 4 lb piece of CU, transformer buss bar that fits tight in a wooden cigar box. I think that I’d rather use that. Maybe not - all my cases are already bonded to ground.

Glad it works for you.

I filled the box with a mixture of tree charcoal, Hawaiian charcoal salt, rock salt, copper filings, and some local dirt.

@guakus ,  how did you decide on what to fill the box with? And what grounding properties do these materials have? In another thread, the box was filled with crystals, among other things.


I researched industrial grounding backfill material.  I found that the premium blends were just charcoal and salt.  A few had quartz.

My understanding is, the mixture needs to have the ability to be semi-conductive as well as maintain a certain amount of moisture.