My First Ground Loop Problem

[Jack N]

I got rid of my old CD player and replaced it with a Denon DN-1200F. And wouldn’t you know it, instant ground loop problem. I get a very irritating low level hum that’s always there at the same volume, so in-between songs it’s much more irritating. Not ever having had a ground loop problem before, I know absolutely nothing about them other than the article that I found here at the Audioholics site. I’m not sure I truly understand what was said in the article, but I was able to discern that there are different types of ground loop problems. So to help me understand exactly where the loop is coming from, the first thing I did was to simply find an extension cord and plug the unit into a different circuit in the house. That didn’t help at all. Next, I tried using one of those 3-prong to 2-prong adapters. It worked. The irritating hum could only be heard in-between songs, and then only if the volume was really high. I removed the adapter, and the hum returned. I really don’t like the idea of having only a single ground for this very expensive CD player, so is the only safe and logical solution to use an isolation transformer, such as those made by Tripp Lite?

 

[Lincoln]

Before you start throwing money at this problem you might want to do some more testing. I would disconnect each piece of hardware from your preamp, one at time, until you find the offending component. I don't know if you have Cable, Satellite, or OTA but I'll bet if you have cable then that's the problem. IMHO, if it is cable or sat then you are better off floating the ground on the RG6 cable from the wall instead of adding the Tripp-lite box plus it's incredibily inexpensive to do using two 75-300ohm converters connected together on the 300ohm side inline on the RG6 cable from the wall.

 

[zumbo]

I used a cable isolater to solve my problem. Click here for product. You can purchase it here.

There was one person on here that this model did not work for. They got the Jensen model that Audioholics recommends & it solved their problem. Jensen

 

[Jack N]

I was surprised to read that both of you thought the hum was still cable related. So I completely removed the cable from the system, and unplugged my cable box from the wall outlet. The hum still remains. I'm not sure what I should try next.

 

[Lincoln]

Cable is the most common culprit of ground loop in HT systems. Try running the system with everything disconnected except the new player and any equipment necessary to make that play, if it still exists with just that component hooked then it might be the new player is more suseptable to RFI then the old one. If that is the case then move then physically move the player away from the other equipment and see if that changes anything, BUT I would return it and try something different.

 

[Audioholics]

plus it's incredibily inexpensive to do using two 75-300ohm converters connected together on the 300ohm side inline on the RG6 cable from the wall.

That solution will fix the ground loop, but severely mess with the quality of the signal, not to mention break digital cable channel reception.

 

[Jack N]

I already tried removing all of the cable components from the system and it didn’t make any difference. I even unplugged the cable box from the 110v wall outlet. So I have a tendency to think that it’s not cable related. I shut down the entire system except for the receiver and the player, and I still get the hum. The player sits about 4 feet away from the nearest possible RFI generator. It’s actually in another room. Is it possible that the unit is just that sensitive to RFI ? The unit was bought used so returning it for something else isn’t an option. The previous owner says he didn’t have any trouble with it at all. Seeing as how the problem goes away when I use a 2-prong to 3-prong adapter, is there another way to ground the unit - IE running a wire to a grounding rod outside?

 

[zumbo]

Did you disconnect the cable (coax)? The coax is usually the culprit. Not the "cable box".

Just checking!

 

[Jack N]

Yup. As far as the cable is concerned, there wasn't anything physically or electrically connected in any way. Do you think the grounding rod thing would work ? I'd have to wait until spring to install one though. The ground up here in Minnesota is frozen solid this time of year. Or do you think I'd be better off trying an isolation transformer ?

 

[zumbo]

Don't know.