Originally Posted by NickThatStands
i feel like i read that at one point.. so what exactly do i do with the tomatoe paste?? or are you saying to go ahead and buy the little 10$ isolater thingy? I thought the issue was that the cable coax wasnt grounded properly, and grounding it to the same spot everything else in the system is grounded to was the idea. so thats why i did what i did, and it helped tremendously.
Let me know exactly what you think i should do, and ill try and give it a whirl. you have to understand, when the issue arose i read and read and read, and there are 8 kajabillion people with 72 trazillion different solutions to what seems to be the same exact problem for 75% of the folks. Tough to pick which is right.
I'm in a similar boat. Yamaha 667 to ART Clean Box Pro (RCA) to amp input (XLR). AVR > converter > amp.
I have 3 Altec 9444b amps that I am trying to drive off the yamaha's RCA pre out's in addition to the sub amp.
Now that I finally got around to hooking these EV/Altec 9444b amps up, I am having terrible ground loop noise from any channels of every amp. I tried plugging each amp, the AVR and ART Clean Box into a different house circuits (each individually and then the same) via 12/3 extension cord with no difference in the level of hum. I tried using a 3 way within each scenario to simulate a singular ground point. I thought that one of these things would have created a difference on the level of hum, but nothing changed. It's not a little hum, but a very loud noise. I used a self powered signal source (mp3 player) to test my understanding of ground loop theory and I am left with a slightly audible noise floor at a almost acceptable level with no ground loop hum! (this should simulate a lifted ground or optically isolated signal source as far as I can tell, but this is my first forray into this issue given a 110/120V power source)
So this is partial success
as the hum is gone when the signal source is independently powered, but I still need to have the other components hooked up in the normal signal chain without the hum; but at least this has isolated the source of greatest potential for the ground loop exciting hum.
Can someone tell me if my thinking in this is askew?
I am aware of the gizmos. (the my most likely item of which I could purchase would be the http://www.parts-express.com/pe/pshowdetl.cfm?&Partnumber=245-8650&scqty=1
and to augment all the channels of non-pro/unbalanced to pro/balanced the http://www.parts-express.com/pe/pshowdetl.cfm?&Partnumber=248-6306&scqty=1
instead of buying another 3 art clean box devices) I am trying to avoid buying yet another little thing / multitudes of them to get the pro amps to play nice with my home audio gear. Interestingly enough, image results for ground loop search on google were helpful. In picturing the issue as a schematic, I thought that I can get something to work with some creative wiring/chassis grounding.
And that went like this:
I did some DMM testing via the grounding of the AVR chassis, am antenna plug et cetera, and decided to use the external antenna's ground terminal. (I used the antenna ground as it was quick and easy initially after trying a gaggle of other spots)
With the unit unplugged to verify my thoughts of providing a proper ground path without risking electrical damage to myself or the equipment, I used 16awg stranded wire for the trial as I didn't perceive solid core wire to make any difference, though I could be wrong in this thinking, and it was all that I had within a lazy arms reach. lol
In theory the idea of creating a singular ground source is sound (no pun intended) kinda worked, butttt, in practice I was only able to reduce the ground loop initiated hum by at least 50% in the audible range. All that means though is that I can still hear it quite easily, but it isn't quite as loud while ultimately still being equally annoying. Is there such a thing as a partial fail? lol
So what is next? Should I go and buy some random ground eliminator thing like the radio shack unit or go for the ART T8 8-Channel Transformer Isolator or XLR ground lift plug thing???
I would appreciate any and all thoughts, ideas, or real world recommendations.