New Rotel/BW setup, ground problems, 1080

[JBall]

I set up my gear last night a fired it up. I bought the 1067 and the 1080 to bi-amp the fronts. I bought the Nautilus 803's. Inital thoughts, they sound much better than in the store. In the store they were actually too bright and wasn't blown away, i think the room was poor too. I bought them more from what i researched and build quality/reputation. I am upgrading from an old huge pair of Bozak's (made in the early 70's?) There is much more bass than i thought, maybe because of the 1080. I have yet to buy the expensive speaker cable til i figure out where i want everything. I did buy a good interconnect with some kind of battery to power the line

The problem i am having though is:
When i plugged in the 803's and i put ear near them, i hear a slight hum/scratching sound even with all off, 1067 IS in standy mode so there si some power somewhere. I completely unplugged the cable box and all video equipment. Furthermore, when i turned on the 1080 and the 1067, there was a very loud hum.

I called my dealer right away, he said he knew what problem was. He said the 1067 is a "2 pin" power cord, and the 1080 is 3 pin (grounded). He said short term fix was to get a little gray 2-3 adapter and float the ground of the 1080. He is calling Rotel for the long term fix. The lound hum did go away but the little one is still there.

1) Has anybody already tackled this problem?
2) Am i killing anything to float ground?
3) Will one of those big monster power units make any difference?
4) Is the little hum normal (dealer called it Thermal Noise)

By the way, i have found it invaluable to have a dealer to go to on this level of purchase rather than the mail order/internet route!!!

[Andrew Pratt]

I did buy a good interconnect with some kind of battery to power the line

:scratchhead: Those sound somewhat like MIT cables. If you're interested we can talk about those some more.

1) Has anybody already tackled this problem?
2) Am i killing anything to float ground?
3) Will one of those big monster power units make any difference?
4) Is the little hum normal (dealer called it Thermal Noise)

1) Yes its very common for people's electrical systems not to be grounded properly.

2) Yes possibly yourself! The gound pin is there to direct any shorts from the case to the house ground so that you don't come into contact with dangerous current should the amp fail. I don't recomend this as a long term solution...in fact they're illegal here in Canada for that very reason.

3) Maybe but I'd rather see you fix the root of the problem then try to mask it.

4) Yes most systems will have a very low level background noise that you'll hear in the tweeters with your ear up close...if you can still hear it several feet away that's a different story.

What you should do instead of spending money on the monster unit is get an electrician in to properly ground the house. This will be a better investment in the long term then a quick unsafe fix now. I'd also suggest doing a search on the subject both here on the guide and on the web as there's a lot of discussion on this topic that you can learn from.

[JBall]

Update

My dealer just called, He had the following fix:

Said his techs and Rotel suggested (simple and inexpensive) to take a piece of wire and connect a screw between the two chassis. Said this would ground both on same loop.

Secondly thought a filtered power strip/conditioner might help (since i just got stuff, i am using a $10.00 surge strip

Third fix, he said Jensen (sp?) Transformer would go between all units and lift the ground safely, but he wanted to avoice cost ($200 approx) if he could.....

gonna try the wire first. and I am gonna order a monster power unit to be safe. Worst case if i don't need it i can use it for my bedroom home theater, when i power that up lights dim in house....

[Mitchell]

I'll add this for whatever its worth.
I hooked up my cable box to the Rotel Preamp for 2 channel use so I could listen to some of the cable music channels through the stereo.
Immedialey i got a loud hum that would not go away even when selector switch was set to CD or tuner.
I ran the cable input through my monster strip and plugged the cable box AC into the strip and it completely went away.
I called the dealer to discuss and they said it was very common to have ground loop issues especially from cable (Time Warner in our case).
I know this is not your exact problem but its often helpful to hear of similar issues.

[Andrew Pratt]

Yes Satellite and Cable coax feeds are the primary cause of inproper ground loops. You can purchase "grounding blocks' from places like Radio Shack to splice in on your cable feeds to allow them to be properly grounded.

[Eiffel]

I'm surprised to read that you have a RB-1080 with a three prong connector... my UK spec one came with a cord with a three pronged connector to plug into the power mains, but the end of the cord that plugs into the back of my RB-1080 has no ground connection... and there is no ground connector on the back of my RB1080!

Could this be a design change? (My unit is recent, and doesn't have any hum issue at all)

[JBall]

update 2

I hooked up the ground wire between the chassis and it went away.

Until a few hours later when i went to watch tv, i noticed that i forgot to hook up the cable box to Video 1, as soon as i did there came the hum. I tried a bunch of things, finally took a wire from the 1080 to the cable box, that took away 95% of it.

I did order a Monster 5100 today and will filter all lines and the coax, i will post once i get done. Gonna call dealer again in morning too. This is and A/V receiver, shouldn't be this much trouble to hook up A/V....

Yes, the 1080 certainly is three prong. I wonder why the 1067 isn't? both are brand new

[audiofan]

JBall,
Just wondering how you connect wire between the chasis. I have the same problem with rb-1080. The only difference is my system has no Cable/Sat connected.

Do you just use a bare copper wire or just a simple electrical wire? I may try a filter power surge. However,based on the manual , it is suggested that rb-1080 connected directly to the wall outlet.

Thanks.

[sikoniko]

I'd recommend the brick wall 2raud over the monster. It only has 2 power outlets, but is worth the money.

check out their website, they have a faq that compares themselves to the monster.

http://www.brickwall.com/

[simonb68]

Don't know how practical this is to anybody, but I had the same problem with my RB991 and 993 after getting Sky installed (UK satellite system). Anyway after I connected the audio out of my PC to an analogue input on my 1055 the problem went away, so looks like the PC is grounding it. Not a great solution and I'll probably look into getting a proper grounding unit, anybody have any recommendations for something I can source in the UK for a satellite box?

Thanks
Simon

[JBall]

NO more hummm

to answer the above question, i just went to Home depot and bout some green wire (feels better being green) that was a little stiff so i could route it as i liked, then i crimped round lugs on the ends, backed out a screw on the chassis of the 1080, and did same on 1067. Then to be sure i also took one from same screw and inserted under grounding prong on plug before i put it in the strip.

ANYHOW, i took delivery of a Signature Series Monster Power 5100 that i picked up on ebay for a couple hundred under list. It looks FANTASTIC above the 1080 as the center is silver and ends black. Best part is, i did not connect any little green wires as I hooked everything...and Lo and Behold - NO HUM. Nothin!

I don't know if it is that the coax cable is being filtered, or that all the audio and video is separated inside the monster, i really dont care. I am just glad that there are no issues, and i feel that i am a little safer and the sound certainly can't be hurt by clean power.

I did ask dealer about one, and he said he loves using them, at least he said the monster power strip should be used as it filters the coax.

By the way, I also got a 3600 for my bedroom setup (just a sony/boston acoustic system) but i have a nice Sony Wega direct view. I would get the lights to dim in adjacent rooms as i powered it up before, and would occasionally get crackles in speakers while watching TV. I just finished hooking this one upstairs and no crackles, or dimming lights. I have only had both these untits working for a couple hours, but SO FAR SO GOOD!!

I think its a worthwhile investment to protect equipment. I know there are others out there than monster, i am sure do same thing.

Hope others can benefit, I'll update here if anything changes

[EAmin]

Sorry for the silly question. But are you saying that you plugged in your sat/cable box to one of the outlets on the power center AND ran the cable connection from the wall through the coax connections on your 5100? Just wanted to confirm.

[JBall]

yup

everything runs thru the monster power center. I guess there are potential surges across any of these lines, and they can interfere with each other. They even provide a phone cord and coax as jumpers. If you have a directv box you need a phone line to buy PPV. So EVERYTHING runs thru the box. Go to monsterpower.com, they have a very good website with diagrams

[rhoffman000]

Regarding the Jensen ground loop isolator. It solved the ground loop problem, but caused problems with the FOX HD channel and it seemed to cause a problem with our DVR Cable box (the recorded video would sporadically stop & start). I have Time Warner Cable in NYC.