Double ground system

Hallo!
I´ve just experimented a bit with the grounding of my rig:
First I´ve to mention some points of the general setup: The Poweramps run on isolation transformers. The preamp and sources run on a battery powered ac- generator.
All audio grounds have no connection, except some very slight capacitive coupling, to the line ground (earth- potential).
I got very good results with the following connection of grounds: All filters are connected to the normal ground, all cases of the units are connected to an extra ground, I build by means of a massive alloy ground anchor, going 1,6 m deep into the soil next to my listening room. That anchor is connected by 3 m of 16 mm² cooper cabele to a very solid steel-bar, which I hammered 3 m deep into the soil. That system is also by 16 mm² copper cable conected to my master ground point near the power distribution. Also the Rack I´m using is connected to that ground.

Sonic results is first much more dynamics, better room(width and depth), more naturalness especially of voices.

In comparison to the price of the material and the work spent, a very nice improvement! Costs were about € 100.- To get the same kind of improvement, for example I had to go from Nordost Heimdal to Audiaz interconnects, which cost me more than 10 times the ground system.

Just ry it yourself!

Best regards
Stephan

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Hello Stephan,

Thanks for the tip, grounding is very important as it can kill the good things in the sound completely if not taken care.

My signal ground is nowhere connected to earth ground except at one point taken from the system (the pre-amp worked best in my system). For the rest all housings and table is connected to earth working as a good RF shield.

Since 2 years I have a new earth with measures resistance of only 7 ohms (if I remember correctly) ! :cool:

Having such a low resistance makes it sure that all floating current is directed away from the system to that earth (current is lazy and will only take the most easy way - low resistance!)

Mine went about 28m deep through very hard ground (the best for low resistance) which only could be done with a machine...

It did not cost too much either (around 300 Euro including labour) for a clean and safe ground! Normal earth is between 50-100ohms and called safe... :shame:

Cheers,

Bert

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BD-Design - Only the Best!

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Hallo Bert!

That is really impressive! 28 m deep! Tomorrow I´ll measure my earth-resitance exactly - it´s tricky to meaure, cause of a floating system havin allways some offset, which spoils the resistance measurement.
It´s allways nice to see, that we follow very similar paths of audio improvements...
Best regards
Stephan

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Hello Stephan,

It is only 15m deep, I remembered incorrectly... :blush:

This was what we found out at my place while getting this earth in the ground using in total 5 pins connected to each other (each pin is 3m long):

1st 3m - 211 ohm
2nd 3m - 42 ohm
3rd 3m - 12 ohm
4th 3m - 7 ohm
5th 3m - 7 ohm

More didn't help so we stopped there. The last 3m was useless, the resistance didn't drop any further after we went all the way through the hard ground.

Cheers,

Bert

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BD-Design - Only the Best!

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Hallo Bert!

Quite an impressive effort You did! I just measured my System, it has a DC-Resistance of 16,24 Ohms. I think, I did not go as deep as You, but I have a bigger surface, so that explains the rather good measurements. But it also depends on the amount of water in the surface area. When it is dry, like the last weeks, the alloy anchor is getting a higher resistance. So in that situation I´ve to put water to the anchor...

Best regards
Stephan

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Hello Stephan,

Quite an impressive effort You did! I just measured my System, it has a DC-Resistance of 16,24 Ohms.

Not bad either!

But it also depends on the amount of water in the surface area. When it is dry, like the last weeks, the alloy anchor is getting a higher resistance. So in that situation I´ve to put water to the anchor...

I guess it would not go too high with dry weather but in case the sound gets worse then keep it wet! :wink:

Bert

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BD-Design - Only the Best!

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How did you guys measure the resistance? I have a 50m. long 25 mm2 copper-clad wire laid out 3m. below ground, in a 25m. long ditch (the wire goes back and forth so that if, by any chance, it should be broken, I will regardless have the same total surface because both ends go into the house.

At this depth, the soil is very moist, especially since some drainage is directed to this area also.

I did this in the same moment as we were changing the water inlet pipes, so it only cost me the price of the wire and a couple of hours work drilling through the concrete wall and fixing a solid copper connection bar on the inside. A very rewarding "tweak" at the price of a few CD's......

My listening room is basically 2m. below ground, steel reinforced concrete floor and walls (insulated and lined with solid pine etc.). The steel reinforcement acts as a "cage" and effectively picks up RF noise. This steel cage is connected to the regular ground system that runs 2m. below ground, all around the house. I am now installing a heavy duty contactor (relay) with a simple remote switch, so that I can connect/disconnect the two ground systems to each other during playing.

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Hello JAM,

How did you guys measure the resistance?

I didn't measure it...the guy working hard to get the pins into the ground did that using special measuring equipment (expensive stuff!).

The principle used for measuring earth ground is rather different than using a multi-meter to check resistors. I think it uses high Voltage pulses and checks what comes back but I could be completely wrong here...

I am now installing a heavy duty contactor (relay) with a simple remote switch, so that I can connect/disconnect the two ground systems to each other during playing.

Good idea! Not sure if your earth is doing a good job though to be able to compare but you could ask a company working with electricians to measure your earth. It takes only a few minutes...

Bert

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BD-Design - Only the Best!

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For measurement of the ground resistance are man was to do it:
I use a HP 4192A Impedance Anazer ( 5Hz - 13MHZ) to look also at AC frequences.
Another wa to measure the DC resistance is to connect a powersupply (10 V / 10 A) between normal groun and audio ground. Increase the voltage slowly till you get a reading of about 5 amps. Than you can calculate the ground restance = Voltage divide by amps. Don´t forget to swithch all your equipment off before!
Best regards
Stephan

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Hello Stephan,

Thanks for the additional information.

Another way to measure the DC resistance is to connect a powersupply (10 V / 10 A) between normal ground and audio ground.

Can you please provide a schematic where and how to connect all things to make it clear to me? :confused:

Bert

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BD-Design - Only the Best!

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Hallo Bert!
You don´t need a schematic! Just take a normal regulated powersupply - coGCnect minus to "normal" earth, coGCnect plus to audio earth. Increase the Voltage, until You have a reading of 2-5 Amps. Read the voltage. Than calculate the DC-Resistance. When I got time I´ll make a photo of the setup here!
Make sure no audio/video equipment is connected the same time to audio and normal earth ( sat-receivers, tv, beamers, etc) - cause that could damage the equipment.
Best regards
Stephan

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Hello Bert,

Next week a construction company will drill 5 steel poles in the ground to support my house. They will be 8 meters deep.
I was thinking about connecting the 5 poles with the ground of my gear, and disconnect the ground from the main AC which has its own ground (= aardlek (differential switch?)). Could this be usefull or am I going to do something stupid?

Best regards,

Frank

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Hello Frank,

Next week a construction company will drill 5 steel poles in the ground to support my house. They will be 8 meters deep.

Good, that will ensure a safe earth and probably already a lot better than standard earths... :wink:

I was thinking about connecting the 5 poles with the ground of my gear, and disconnect the ground from the main AC which has its own ground (= aardlek (differential switch?)). Could this be usefull or am I going to do something stupid?

Your "Aardlek" does not work through earth as far as I can tell, it measures the differences between the hot and neutral and switches off when the difference is too big.

Best would be to use the new earth and add a new fuse box for your audio group. Not sure how far you can go with regulations though (think insurance with fire and such).

Bert

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BD-Design - Only the Best!

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Double ground system (Tweaks)