OK so these sound great I build 4 monoblocks and couln't be happier with the way they perform but when introduced to my main system they hum like mad. I isolated the majority of the noise to when the television is on and it dies to almost a dead silence when it isn't on. I have a satalite reciver within 6 feet and also several other pieces of kit, all plugged into a monster stage 2 power conditioner. So before I go and add a few 220uF caps accross the inputs I'd like to hear what others think, plugged into any other socket with an Ipod or another media source they are quite dead silent, odd but I'm thinking of resoldering the grounds with solid core wire grounding to the post in my 1/8" aluminum chassis.
Any suggestions, RF, ground loop, heck anybody it's driving me nuts.... Peace.
Any suggestions, RF, ground loop, heck anybody it's driving me nuts.... Peace.
Forgott to mention that they are currently running in a Bi-amp system with a Fostex FE126E and four Siver flute 5.5" so even with the silence I can still hear some hum due to the efficiency of the system, this I'm not worried about, more the hum I get when other electronics specifically the television are turned on, because a horrible and very audible hum isn't going to fly with me.... Grounds seem good so I'm thinking RF or something to do with a signal they are sensitive to being transmittted by the TV. You'd think with so much metal around them they wouldn't be so sensitive, kind of a faraday cage type deal.... Oh well.....
So back to the drawing board, Peace.
So back to the drawing board, Peace.
Thanks for the suggestion Pacificblue (for the second time LOL), I'll take a look at our local Ratshack and tell you if it made any difference. I know it's not a construction issue as I made sure to take things slow and ensure proper build so my other guess like you say is a ground loop. I'll try this and maybe get some 220nF caps while I'm out also.... Peace and thanks to all who helped.
You can try this:
(Credits to various owners of schematics found on diyaudio)
Easy to implement and doesn't hurt the signal a bit.
An externally hosted image should be here but it was not working when we last tested it.
(Credits to various owners of schematics found on diyaudio)
Easy to implement and doesn't hurt the signal a bit.
The arrow pointing up is to be connected to the chassis ground, so instead of connecting the chassis ground directly to the ground or earth wire you connect it through this.
What the diodes do, is they have a voltage drop of 0.7V across each of them, so any ground loop signal through the earth wire will be blocked. But in the case of an earth leakage, the diodes will allow 110V to pass through for the circuit breaker to trip.
Reason for the loop, it's diodes pointing opposite directions in parallel actually, is because AC supply keeps switching between positive and negative.
By the way is the amp connected to the TV either directly or indirectly?
What the diodes do, is they have a voltage drop of 0.7V across each of them, so any ground loop signal through the earth wire will be blocked. But in the case of an earth leakage, the diodes will allow 110V to pass through for the circuit breaker to trip.
Reason for the loop, it's diodes pointing opposite directions in parallel actually, is because AC supply keeps switching between positive and negative.
By the way is the amp connected to the TV either directly or indirectly?
The amps are not connected to the Television whatsoever other than being plugged into the same Clean power unit. The only RF signal would be my in from the satellite, everything else runs RCA, DVI or HDMI to the TV from there. I don't get it.
Odd part is I can hear the transformer power up on the Television and can also hear the degaussing circuit on the TV charge thru the amps when the TV is turned on, then the steady hum once it runs it's course. I can't reproduce this in any other room with a satellite and TV although the other TV's are actually LCD's. Accept for a very very small hum when my ear is close the other rooms don't have the same artifacts. Could I be picking up interference from the TV itself, this is a 34" 16:9 Toshiba tube unit.
The diode loop(?) I may try if I can't isolate the issue and fix it, as this seems like a good alternative, any suggestion on what diode types?. Everything would then ground to the arrow pointing down from my star ground point correct? If I can't get rid of the issue I'm looking at 4 monoblocks that will have to move to another system because the hum is vexing to say the least....
Odd part is I can hear the transformer power up on the Television and can also hear the degaussing circuit on the TV charge thru the amps when the TV is turned on, then the steady hum once it runs it's course. I can't reproduce this in any other room with a satellite and TV although the other TV's are actually LCD's. Accept for a very very small hum when my ear is close the other rooms don't have the same artifacts. Could I be picking up interference from the TV itself, this is a 34" 16:9 Toshiba tube unit.
The diode loop(?) I may try if I can't isolate the issue and fix it, as this seems like a good alternative, any suggestion on what diode types?. Everything would then ground to the arrow pointing down from my star ground point correct? If I can't get rid of the issue I'm looking at 4 monoblocks that will have to move to another system because the hum is vexing to say the least....
Since it's not connected to the TV it may not be a case of ground loop, but your big CRT TV dumping noise into the power supply. In that case have your amp connected to a different wall-outlet/distributor as far away as possible from the TV and increase the amount of filtering in the amp's power supply unit.
Test whether the fault is due to ground loop, somehow disable the earth connection (my country uses UK 3-pin plug, rotate the plug 180 degrees and plug it into a 3-way adaptor), connect only one signal connector and check for hum.
(Hope I don't receive any flak for disabling the earth, temporarily)
Or, unplug all signal connections, power up the amp and TV, listen for hum. If it still does, it's not the grounding.
Re: ground loop breaker, the one in pacificblue's link (using a bridge rectifier) is safer and more complete, go for that one. If you need it. Hopefully you don't.
Test whether the fault is due to ground loop, somehow disable the earth connection (my country uses UK 3-pin plug, rotate the plug 180 degrees and plug it into a 3-way adaptor), connect only one signal connector and check for hum.
(Hope I don't receive any flak for disabling the earth, temporarily)
Or, unplug all signal connections, power up the amp and TV, listen for hum. If it still does, it's not the grounding.
Re: ground loop breaker, the one in pacificblue's link (using a bridge rectifier) is safer and more complete, go for that one. If you need it. Hopefully you don't.
The fact that the noise only appears, when the TV is connected, had me thinking about a ground loop through the earth connection. One end would be the earthing of the the satellite dish/LNB and the other the earth pin on the wall outlet. That is, where ground loops often appear, and what the ground loop breaker from post #2 deals with. You could check that without compromising safety by just disconnecting the antenna cable from the TV and/or the satellite receiver. If the noise is gone, use a ground loop connector.
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