justin_tx_16 Posted February 24, 2002 Share Posted February 24, 2002 Ok, i am setting up another mini home theater using my latest set of ProMedia 5.1's, got them today (that makes 3 sets of wonderful 5.1's... yeah, i know, should have just saved the $1200 and gotton a real system, but I have very little logic in that respect...). Right now i am using my old Sony DVP-NS400D DD 5.1 output so i can hook up to the PM5.1's without a decoder which i will get in a few months when my new Mitsu. 51" or 55" (whichever it is) comes in. Meanwhile i am using the NS400D with my Toshiba 27" TV, just plain RCA analog input. Ok, when i play music and dvd's with the DVD play, not connected to the TV, it sounds great. But upon plugging in the RCA cord (gold plated) to my DVD from the TV a loud buzz occurs. I have them all on the same surge protecter, switched around ever combination of directs the plugs could be in on the surge protecter (not EMI/RFI filtered...) and to no evail. Unplugging the RCA cord fixes this, whether from the TV or from the DVD player, but this realy hampers watching a movie haha. so, should i just wait for my new TV and see if it has the same problem, though it will be hooked up Y Br Pr (or whatever they are called, i have forgotton, don't look to the back of my DVD players or other Mistu. HDTV often )? Do you think an EMI/RFI filter would fix this problem? The only things plugged in are the TV, DVD, and PM 5.1's. Let me know what you think, thanks. ------------------ -justin I am an amateur, if it is professional; ProMedia help you want email Amy or call her @ 1-888-554-5665 or for an RA# 1-888-554-5665 Klipsch Home Audio help you want, email support@klipsch.com or call @ 1-800-KLIPSCH RA# Fax Number=317-860-9140 / Parts Department Fax Number=317-860-9150 ProMedia 5.1 Placement Help s> Quote Link to comment Share on other sites More sharing options...
montigue Posted February 24, 2002 Share Posted February 24, 2002 I'm having the same problem with my dvd. I can hear a buzz in all my speakers. Sure would like to know whats up with that. I'm also getting a buzz in my SVS when I turn the samson amp db contoller nob past 3/4's of the way up. Quote Link to comment Share on other sites More sharing options...
chickey Posted February 24, 2002 Share Posted February 24, 2002 Justin, You have a ground loop, which is creating the hum. Click below and read the following thread, which may help solve your problem. If not, post back. http://216.37.9.58/ubb/Forum9/HTML/001408.html Good luck! Colin ------------------ My System Quote Link to comment Share on other sites More sharing options...
justin_tx_16 Posted February 24, 2002 Author Share Posted February 24, 2002 ok, here is some more info. I can unplug the TV and the DVD player, just have the PM5.1's plugged into the surge protecter or just the wall outlet and with the DVD hooked to the TV i still get the hum, even with the TV and DVD not plugged into the power. any ideas, or is this still a ground loop... ------------------ -justin I am an amateur, if it is professional; ProMedia help you want email Amy or call her @ 1-888-554-5665 or for an RA# 1-888-554-5665 Klipsch Home Audio help you want, email support@klipsch.com or call @ 1-800-KLIPSCH RA# Fax Number=317-860-9140 / Parts Department Fax Number=317-860-9150 ProMedia 5.1 Placement Help s> Quote Link to comment Share on other sites More sharing options...
chickey Posted February 24, 2002 Share Posted February 24, 2002 Justin, Disconnect the cable TV feed from the back of your TV, plug the RCA from the DVD to the TV, and see if you still have the buzz. If not, you have a ground loop. In this case, the cable TV feed has a different ground than than the electrical wiring in your house, which creates a potential difference. The buzz you are hearing is a symptom of this potential difference. If the buzz is still there, you may still have a ground loop, but it may be more difficult to solve. But let's cross that bridge when we come to it.... Colin ------------------ My System Quote Link to comment Share on other sites More sharing options...
justin_tx_16 Posted February 24, 2002 Author Share Posted February 24, 2002 i will go try that. if the buzz really is coming from the cable tv, how can this be fixed? ------------------ -justin I am an amateur, if it is professional; ProMedia help you want email Amy or call her @ 1-888-554-5665 or for an RA# 1-888-554-5665 Klipsch Home Audio help you want, email support@klipsch.com or call @ 1-800-KLIPSCH RA# Fax Number=317-860-9140 / Parts Department Fax Number=317-860-9150 ProMedia 5.1 Placement Help s> Quote Link to comment Share on other sites More sharing options...
chickey Posted February 24, 2002 Share Posted February 24, 2002 The cheapest way is to put two matching baluns (75-300 ohm converters) back to back in line with the cable TV feed. Insert them at the end of the cable feed which you would normally plug in to your TV or VCR. The more expensive option is the Mondial Magic Box, which is described in more detail in the products section of this website. Hope this helps! Colin ------------------ My System Quote Link to comment Share on other sites More sharing options...
montigue Posted February 25, 2002 Share Posted February 25, 2002 can you have the same problem if you have satelitte tv? I noticed that they used my outside water piping for ground. Quote Link to comment Share on other sites More sharing options...
chickey Posted February 25, 2002 Share Posted February 25, 2002 Montigue - Yes, absolutely. Colin ------------------ My System Quote Link to comment Share on other sites More sharing options...
boa12 Posted February 25, 2002 Share Posted February 25, 2002 you'll find cable tv usually has 2 other grounds. one at the house & also at the cable station. so cable tv is real bad. even the magic box didn't completely take the buzzz away for me. plus i thought it did degrade the video quality some for me. & i have like 8 other connections to the prepro that provide the ground loop. & no i will not go w/o these & no i'm not getting 8 ground loop isolators that don't work completely & would cost over $500. being a stickler for audio/video quality over safety, i just opted for the 50 cent cheaters on the pre/pro, amp & sub. no ground loop. though i'm going to electrical safety hell. ------------------ My Home Systems Page Quote Link to comment Share on other sites More sharing options...
justin_tx_16 Posted February 25, 2002 Author Share Posted February 25, 2002 ok, it is the cable tv. i unplugg it and silence is all i hear so what exactly do i need and how much will it cost me? haha ------------------ -justin ProMedia 5.1 Tech Help I am an amateur, if it is professional; ProMedia help you want email Amy or call her @ 1-888-554-5665 or for an RA# 800-554-7724 ext 5 Klipsch Home Audio help you want, email support@klipsch.com or call @ 1-800-KLIPSCH RA# Fax Number=317-860-9140 / Parts Department Fax Number=317-860-9150s> Quote Link to comment Share on other sites More sharing options...
chickey Posted February 25, 2002 Share Posted February 25, 2002 Justin, See my previous post re the matching baluns. Esentially, these are transformers that convert a 75 Ohm cable feed to 300 Ohms (and vice versa). They usually come packaged with your TV. They have an F-pin on end and two spade lugs on the other end. Wire two of them back-to-back in-line with your cable feed. In other words: 1. Take your cable feed and terminate the male F-Pin into a transformer with a female F-Pin connector 2. The other side of the first transformer should have two spade lugs... 3. ...take these two spade lugs and connect them onto the receiving screws of the second tranformer 4. The second transformer should have a male F pin connector at the other end, which you can then plug into your TV or VCR This essentially isolates the group loop and prevents the hum you describe. The parts are available at Radio Shack if you don't have them for about $3 for the two. Hope this helps, C ------------------ My System Quote Link to comment Share on other sites More sharing options...
Connor Posted April 2, 2002 Share Posted April 2, 2002 Colin What do you suppose is the difference between the reversed 300 Ohm baluns and the Mondial Magic Box? (besides $97) I discovered the reversed balun scheme a few years back and I am very happy with it. C Quote Link to comment Share on other sites More sharing options...
Guest BobG Posted April 2, 2002 Share Posted April 2, 2002 The double baluns almost always degrades picture quality while the MAGIC box does not IME. The MAGIC box is a unique approach to ground isloation and also affords protection from the static problem sometimes associated with cable. It will NOT work with a DSS satellite system as that sends DC voltage along the shield to power the LNB at the dish. Quote Link to comment Share on other sites More sharing options...
chickey Posted April 2, 2002 Share Posted April 2, 2002 Definitely agree with what BobG said. I use a Mondial Magic box (picked up long before they became part of the Klipsch family) and they do work. As Bob said, no picture degradation. The balun trick also works as a quick fix, but depending on your cable signal strength, it may create a new problem in fixing the existing one. In my case, the baluns eliminated the hum, but becuase my cable signal is split 4 ways as it enters the house, the addition of the baluns created some degradation of the picture quality. Not huge, but noticeable on weaker stations. It was worth the upgrade to the Mondial box in my case. Your own results may vary. Try the cheap fix first and see if it works to your satisfaction before shelling out the extra bucks. Colin ------------------ My System This message has been edited by chickey on 04-02-2002 at 04:18 PM Quote Link to comment Share on other sites More sharing options...
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