Connect that ground to where the house ground and lightning ground are connected thereby creating a star ground. This way the voltages across the ground rods will be the same in the event of a lightning strike. As a bonus, the (somewhat) equal voltages will deter stray currents into the neutral and lower that hum even more.
Acceptable Level Ground/Earth Noise
Hi Everyone
I have a dedicated earth for my audio system. I was digging a bore for water and lost the rod so decided to dedicate that bore for Earth. It is about 100 feet deep an is in water. The line runs straight to my dedicated audio room and is shared among the various audio components.
I am running a Clearaudio DC preformence through an Avid Phallus phone stage hooked up to a ML No. 38s pre. The cartridge is a clear audio virtuoso MM. The ML volume level goes to 92 and the hum appears at 60. Previously when the earth was shared the hum was almost unbearable at 60 but now is significantly reduced.
My question is that is the hum just part of the analogue experience or should it be absolutely quite?
I have a dedicated earth for my audio system. I was digging a bore for water and lost the rod so decided to dedicate that bore for Earth. It is about 100 feet deep an is in water. The line runs straight to my dedicated audio room and is shared among the various audio components.
I am running a Clearaudio DC preformence through an Avid Phallus phone stage hooked up to a ML No. 38s pre. The cartridge is a clear audio virtuoso MM. The ML volume level goes to 92 and the hum appears at 60. Previously when the earth was shared the hum was almost unbearable at 60 but now is significantly reduced.
My question is that is the hum just part of the analogue experience or should it be absolutely quite?
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Srafi, you should follow local laws. If they are not enforced, you still should bond any ground to your service ground. Otherwise you defeat the purpose. As for humming, start a new topic, but depends on your equipment, and if you have DC on the line. DC can be caused by dimmer switches. Here, the usual source of hum and ground loops is external TV like Cable or an antenna, and PC's. In both cases the best solution is a ground loop isolator. Best, Erik |
gs5556, I stand corrected. The lightning electrode system shall be connected, bonded, to the grounding electrode system of the electrical service.
http://ecmweb.com/qampa/code-qa-grounding-lightning-protection-system //
http://lightningsafety.com/nlsi_lhm/grounding_principles_NFPA780.html For the US anyway, per NFPA780 as well as NEC 250.106 and 250.60. If my understanding is correct each grounding electrode system shall have its own grounding electrode/s. The two systems are then connected, bonded, together. I assume by a minimum #6awg copper wire. In other words lightning rods cannot be installed and directly connected to the electrical service grounding electrode system. Is that your understanding as well? Jim . |
@srafi Your utility pole does not provide a ground, it provides a neutral. It’s up to the service entrance to provide a suitable ground. You MUST bond ALL grounds together, and bond that to the neutral coming off the pole. Having said that, you may use as many ground rods as you’d like. :) What you cannot do is arbitrarily use one rod for one room and another for the rest. The reason for this is that is prevents the safety ground from working correctly. If a short develops to a case, and this independent ground rod is 10 feet from the house ground rod it can be many volts different than your neutral now. 10s to hundreds. It’s worse with dry soil. The safety ground should guarantee that the case of your electronics is 0 volts, but if it's at some other, random point, it could be quite higher than 0. That's where you loose your life. :) |
Hi Al, I think Ott hit the nail on the head with #4.
AL, I agree with your post above about disconnecting all that earth grounding that srafi has added, connected, to his audio system. It does nothing for the SQ of his audio. If anything it adds noise. The only ground he should have connected to his audio system is the safety equipment ground.
To me that sounds like the tone arm is not grounded to the signal ground of the phono preamp. LOL, I’m almost hesitant to use the word grounded. Some take the word as meaning mother earth ground. If the TT has a ground wire and srafi has it connected to the chassis of the phono preamp it could be the ground wire connection is open/broken. If that is the case there is a good chance it would be inside the TT. For a simple test he could connect a wire at the phono preamp chassis and then touch the other end of the wire to the tone arm or to the tone arm support tower. If the hum stops he has found his hum/buzz problem. I would also check the cartridge phono wires to make the connections are good. Jim . |
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