Topic: Hum Help!

[Church-Audio]

It’s not the cable box.  I went to Comcast and exchanged mine for a different one (this one has HDMI sweet).  I am pretty sure (if not positive) it’s the cable.  I carefully rechecked connections.  With every thing connected excluding the cable to the cable box, the hum is eliminated.  I tried a fix which uses two 75ohm to 300hom antenna transformers, following the instructions given at this website: http://www.dplay.com/tutorial/cablehum.html
I ran down to my local Radio Shack, to pick up the parts as specified with confidence.  Got home and installed the “trick” and there it was although much less pronounced.  Is this because there is not enough shielding?

I am getting very agitated after a full day of hunting for hum!  I really want to just use the cheater and be done with it.

I have to believe this can be solved.  Can I ground the cable so that it is on the same grid as the house or better yet the outlet circuit?  I am obviously not an electrical engineer or electrician, please keep the options coming.
   

Most times when a cable inters a building the morons ground it to a water pipe.. That is because if lightning strikes it will go to ground, in Canada that's how they do it I am pretty sure in the USA things are the same. The only real problem with that misguided theory is that Water pipes in the ground are no longer made of metal in most cases they are ABS. I would check to see that this connection is solid to your water pipe. The other issue with this dumb practice is The telephone guys also sometimes use a water pipe if you have both systems going to the same water pipe well there's your problem. If you want to solve this problem you can purchase a pair of transformers that are line in line out 1:1 ratio for the output of your cable box. I would also suggest taking the Audio from your TV instead of the cable box.. If you have not already tried that. Please give me a rundown of how all this stuff is connected... Audio, Video, Cable....

[SonicSound]

Please give me a rundown of how all this stuff is connected... Audio, Video, Cable....

Here is the

Cable Box
-Power: to Monster power center > basement outlet
-Audio out: RCA cables to A/V receiver’s DVT input
-Video out: Composite to A/V receiver’s CVT input
-Cable in: coax (tried w/ and w/o the 75-300)
DVD/VCR
-Power: to Monster power center > basement outlet
-No other connection now
A/V Receiver
-Power: to Monster power center > basement outlet
-Video out: HDMI to TV
-Audio out: RCA front channel pre-amp out to Pre-amp
Pre-Amp
-Power: to power strip > first floor outlet
-Input 3: RCA for pre-amp out on A/V (this is the surround through input)
-Input 1: RCA from DAC
-Output: RCA to power amps
DAC
-Power: to power strip > first floor outlet
-Output: RCA to Pre-amp Input 1
-Input: XLR from CD transport
CD
-Power: to power strip > first floor outlet
-Output: XLR to DAC
Power Amps (mono blocks)
-Power: to power strip > first floor outlet
-Input: RCA from pre-amp
-Output: Bi-wire to Speakers

Earlier this afternoon I did take a walk around the house and look at were the cable came into the house.  It was indeed grounded to a hose bib (which is copper).  The main feed goes to a two way splitter one feed to second floor and the other the basement.  Once in the basement it is connected to a slitter with three outputs.  The feed to the cable box is from this splitter. 

Currently, I am not using the surround sound function the A/V unit (on sub or satellite speakers).

The Monster Unit is a Power Center HTS2600.  I have tried running the cable this unit and it does not help.

[SonicSound]

I took another stroll around the house this morning to locate the earth ground.  Turns out the electrical panel’s earth ground is on the opposite side of the house to where the cable enters.  The cable is grounded to a nearby hose bib.  I think this might be part of my problem.  How do I solve this?  Can I use a cable grounding block and connect it to an outlet’s ground pin?     

[Church-Audio]

I took another stroll around the house this morning to locate the earth ground.  Turns out the electrical panel’s earth ground is on the opposite side of the house to where the cable enters.  The cable is grounded to a nearby hose bib.  I think this might be part of my problem.  How do I solve this?  Can I use a cable grounding block and connect it to an outlet’s ground pin?     

No dont mess around with ground. I would call the cable company and ask if someone can come down and fix it. You cant have two sources for ground on the same system with out issues. I think you need transformers...
here is two links to systems that will work.

http://cgi.ebay.ca/ART-CleanBOX-II-Hum-Eliminator-W-1-4-TRS-Jacks-Mint_W0QQitemZ200083483753QQihZ010QQcategoryZ3278QQssPageNameZWDVWQQrdZ1QQcmdZViewItem#ebayphotohosting

http://cgi.ebay.ca/Jensen-Transformers-CI-2RR-Hum-Buzz-Eliminator-Isolator_W0QQitemZ150096636500QQihZ005QQcategoryZ14968QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

This last one is pretty much top end..

[cheshirecat]

I had a similar issue in my apt.  Bought one of these:

http://www.markertek.com/SearchProduct.asp?item=JEN%2DVRD1FF&off=16&sort=prod
Solved the problem... pretty easy.

[krebsy]

Cheshirecat, your link isn't working for me, but is it one of these little iso max in-line rf isolators?  I had a problem much like Sam's.  A nasty 60 cycle hum, but when I disconnected the cable line from the VCR it would disappear.  That iso max gizmo did the trick.

[SonicSound]

Did this unit completely eliminate the hum or just dramatically reduce it?

Cheshirecat, your link isn't working for me, but is it one of these little iso max in-line rf isolators?  I had a problem much like Sam's.  A nasty 60 cycle hum, but when I disconnected the cable line from the VCR it would disappear.  That iso max gizmo did the trick.

[SonicSound]

The cable guy comes tomorrow.  I hope that they willing reground the cable properly (i.e., to the grounding rod and not the hose bib).  I have a bad feeling that this will not eliminate the problem and that I will need to resort to other measures. 

You would think that in an age of technology that a simple problem like this could be avoided.  I think the problem is simple, communication.  People are mainly interested in what they are doing and fail to interact with others for a universal solution.

[cheshirecat]

Cheshirecat, your link isn't working for me, but is it one of these little iso max in-line rf isolators?  I had a problem much like Sam's.  A nasty 60 cycle hum, but when I disconnected the cable line from the VCR it would disappear.  That iso max gizmo did the trick.

Yup. thats it.

I believe this should completely eliminate the hum, not reduce it.  This will isolate the ground on your cable (basically ungrounding it, like using a cheater plug).

[Church-Audio]

The cable guy comes tomorrow.  I hope that they willing reground the cable properly (i.e., to the grounding rod and not the hose bib).  I have a bad feeling that this will not eliminate the problem and that I will need to resort to other measures. 

You would think that in an age of technology that a simple problem like this could be avoided.  I think the problem is simple, communication.  People are mainly interested in what they are doing and fail to interact with others for a universal solution.

This cable solution should work its a transformer, But you need to know it might also degrade your picture. And it might also have an effect on high speed Internet depending on where its placed in the chain. I would suggest placing it right before your cable converter box. Let me know how things work out I would really like to know what solution worked.

Chris Church