NOSValves Posted April 15, 2015 Share Posted April 15, 2015 Geezzz no helping you folks..... Quote Link to comment Share on other sites More sharing options...
mustang guy Posted April 16, 2015 Share Posted April 16, 2015 LOL Craig... I thought your drawing was beautiful.... Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted April 16, 2015 Share Posted April 16, 2015 I am not well versed on ground loop problems but, the hum was more annoying than putting a $ 6 ground loop isolator which made things nice and quiet, lol. Omnimic did not pickup any noticeable increase distortion. 1 Quote Link to comment Share on other sites More sharing options...
Max2 Posted April 16, 2015 Author Share Posted April 16, 2015 Geezzz no helping you folks..... So I need soldered RCA's and a soldered power cables for both the AVR and the Amp and this will eliminate it? I did mention that the AVR has no ground. Is this is the point you're making in your drawing? Quote Link to comment Share on other sites More sharing options...
babadono Posted April 16, 2015 Share Posted April 16, 2015 Trying hard not to be a d**k here but I am confused. The MacIntosh amp with nothing plugged in except the speakers and a GROUNDED 3 prong cord hums? Quote Link to comment Share on other sites More sharing options...
Max2 Posted April 16, 2015 Author Share Posted April 16, 2015 Trying hard not to be a d**k here but I am confused. The MacIntosh amp with nothing plugged in except the speakers and a GROUNDED 3 prong cord hums? No. Humming starts when RCA's are plugged in from AVR. My better RCA's are coming in today and I will start from there. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted April 16, 2015 Share Posted April 16, 2015 Trying hard not to be a d**k here but I am confused. The MacIntosh amp with nothing plugged in except the speakers and a GROUNDED 3 prong cord hums? I took that as a yes. I believe that RCA's when installed are quiet too BUT with the pre, it's noisy. Of course I could be way off base. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted April 16, 2015 Share Posted April 16, 2015 Trying hard not to be a d**k here but I am confused. The MacIntosh amp with nothing plugged in except the speakers and a GROUNDED 3 prong cord hums? No. Humming starts when RCA's are plugged in from AVR. My better RCA's are coming in today and I will start from there. What about RCA's plugged into the amp with the AVR NOT plugged in? Quote Link to comment Share on other sites More sharing options...
babadono Posted April 16, 2015 Share Posted April 16, 2015 LOL Craig... I thought your drawing was beautiful.... Loved the drawing too. But if I understand Max2 only the amp has a earth ground connection and the AVR "ground" should be attaching to this through the shields of the RCA cables. This all SHOULD work just fine, but apparently there is SOMETHING wrong. Quote Link to comment Share on other sites More sharing options...
Max2 Posted April 16, 2015 Author Share Posted April 16, 2015 Trying hard not to be a d**k here but I am confused. The MacIntosh amp with nothing plugged in except the speakers and a GROUNDED 3 prong cord hums? No. Humming starts when RCA's are plugged in from AVR. My better RCA's are coming in today and I will start from there. What about RCA's plugged into the amp with the AVR NOT plugged in? Same sound even with AVR not plugged in. I will have time tonight to ground the AVR and see what happens, I didn't get to do anything to it last night. It seems the satellite RG cables are a big issue from what I have read. Maybe I don't have a ground loop issue after all. Im just going to have to start eliminating things until I locate it. Quote Link to comment Share on other sites More sharing options...
babadono Posted April 16, 2015 Share Posted April 16, 2015 (edited) So perhaps before you added the Mac the earth ground was coming from the satellite feed and all was OK. With the ground connection of the Mac added now you have a loop. I think this is what Dr. Who was getting at. You should be able to test for this by simply unplugging the HDMI(I think that is what you said you use) connection from the Sat box to the AVR. Edited April 16, 2015 by babadono Quote Link to comment Share on other sites More sharing options...
DrWho Posted April 16, 2015 Share Posted April 16, 2015 One thing to keep in mind....the video, data, and audio signals all use the same ground. Any one of those devices can cause problems. These things are hard to troubleshoot from far away. If you made a diagram of every single connection in your system, then we could point at things to try to help narrow down what is happening. Quote Link to comment Share on other sites More sharing options...
Max2 Posted April 16, 2015 Author Share Posted April 16, 2015 So perhaps before you added the Mac the earth ground was coming from the satellite feed and all was OK. With the ground connection of the Mac added now you have a loop. I think this is what Dr. Who was getting at. You should be able to test for this by simply unplugging the HDMI(I think that is what you said you use) connection from the Sat box to the AVR. Negative. With absolutely nothing hooked up to the AVR and just the RCA's going to the amp, the hum or buzz is there. The cables just came in from BlueJean and they look like good quality cables which they say are welded instead of soldered for what that is worth. One thing to keep in mind....the video, data, and audio signals all use the same ground. Any one of those devices can cause problems. These things are hard to troubleshoot from far away. If you made a diagram of every single connection in your system, then we could point at things to try to help narrow down what is happening. Thanks I am just going to hook up the AVR and the amp tonight and if the hum is still there. I will start searching other items that may be the culprit one by one. I have wireless baby camera monitors, a surveillance camera system with recorder for outdoors, Fluorescent lights in the garage below me, my wireless network, The Direc TV mess and so on all within about 30 feet max from my setup. Heck, it could be anything. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted April 16, 2015 Share Posted April 16, 2015 Start with just the amp and speakers hooked up and power it up. Hum/no hum. Add one thing at a time. Next is RCA's. Hum/no hum. Next receiver with nothing but the amp hooked up. Hum/no hum. Do this till you get the hum and report back. Eric will help you from there Quote Link to comment Share on other sites More sharing options...
babadono Posted April 16, 2015 Share Posted April 16, 2015 babadono, on 16 Apr 2015 - 10:16 AM, said: So perhaps before you added the Mac the earth ground was coming from the satellite feed and all was OK. With the ground connection of the Mac added now you have a loop. I think this is what Dr. Who was getting at. You should be able to test for this by simply unplugging the HDMI(I think that is what you said you use) connection from the Sat box to the AVR. Negative. With absolutely nothing hooked up to the AVR and just the RCA's going to the amp, the hum or buzz is there. The cables just came in from BlueJean and they look like good quality cables which they say are welded instead of soldered for what that is worth. OK this proves that it is not a loop because of THESE two different ground connections. And yet if you put a cheater plug on the Mac all is quiet? Hmmm. Quote Link to comment Share on other sites More sharing options...
garyrc Posted April 16, 2015 Share Posted April 16, 2015 You are always at risk when lightning or other line surges come to test your surge protector, regardless of grounded or ungrounded units are plugged into it. Should people unplug their equipment during a thunderstorm? I've never known whether this is an Old Wives' Tale. Quote Link to comment Share on other sites More sharing options...
Max2 Posted April 17, 2015 Author Share Posted April 17, 2015 I may have got off easy. I hooked up the new RCA's and it was silent. I slid my rack back around and boom, it came back. Unhooked everything except the RCA's and it was still there. Unplugged the Direc tv cable from the wall which is across the room and it was gone. I don't know how it is spilling over, but it was. The other end of the DTV cable going in to the SAT receiver didn't matter if it was plugged in or not. Something is funky about the cable or the female plug in the wall. I screwed it back on the wall plug all the way down and backed it out just a tad where it was loose and it stopped again. So was this RFI instead of a ground issue? Quote Link to comment Share on other sites More sharing options...
billybob Posted April 17, 2015 Share Posted April 17, 2015 (edited) EMI would be a closer definition although the RCA's did not like the ground on the DTV. This really sounded like a case I had awhile back with DirecTV boxes that they call receivers. Cheaply made. Glad you were able to eliminate your problem. Edited April 17, 2015 by billybob Quote Link to comment Share on other sites More sharing options...
muel Posted April 17, 2015 Share Posted April 17, 2015 You are always at risk when lightning or other line surges come to test your surge protector, regardless of grounded or ungrounded units are plugged into it. Should people unplug their equipment during a thunderstorm? I've never known whether this is an Old Wives' Tale. I unplug a lot of things this time of year. I took a lightning strike in 2008 that resulted in over $8,000 in damages. It was a sudden late Summer storm... sounded like something exploded outside the house. I woke up knowing that it was going to be bad and immediately ran around the house checking for damage. Insurance was a hassle but covered things mostly. Took out strange stuff... garage door openers, exterior lighting transformers, anything connected to Ethernet was toasted (computers, switches, laser printer, KVM box), and the odd clock here or there. Appliances SEEMED fine but all were replaced or repaired within the next 3 years. I think they took the hit but didn't actually die right away. GOOD NEWS was I didn't lose any audio equipment! Only an Onkyo HT was plugged in at the time and it was fine. 1 Quote Link to comment Share on other sites More sharing options...
billybob Posted April 17, 2015 Share Posted April 17, 2015 You are always at risk when lightning or other line surges come to test your surge protector, regardless of grounded or ungrounded units are plugged into it. Should people unplug their equipment during a thunderstorm? I've never known whether this is an Old Wives' Tale. You are always at risk when lightning or other line surges come to test your surge protector, regardless of grounded or ungrounded units are plugged into it. Should people unplug their equipment during a thunderstorm? I've never known whether this is an Old Wives' Tale. I would if I did not have some protection and homeowners. Certainly non-vital items without protection if going on holiday. So many mundane household items usually cause no problem but, as a rule, I would unplug if not being used. 1 Quote Link to comment Share on other sites More sharing options...
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