What solution do folks use for the dreaded BFD hum? - Page 11 - Home Theater Forum and Systems - HomeTheaterShack.com

Reply
 
Thread Tools
post #101 of 330 Old 03-24-07, 10:27 AM
Senior Shackster
lovingdvd
 
Join Date: Jan 2007
Posts: 246
Re: What solution do folks use for the dreaded BFD hum?

Thanks Wayne - yes the pic on page 19 is very helpful indeed! Looks like my local guitar shop has the male XLR so I may go that route instead.

Just one question remaining - how am I supposed to wire the shield of the RCA to the proper pin on the TRS or XLR?

I ask because my understanding now is that the shield will be a braided type of aluminum similar to that found on RG6 cable. So because it is not a wire (rather just "foil") how am I suppose to connect that to the right pin? Am I suppose to take a little wire and wrap it around the shield/foil a few times and solder it there, then connect that to the proper pin?
lovingdvd is offline  
Sponsored Links
Advertisement
 
post #102 of 330 Old 03-24-07, 01:58 PM
Senior Shackster
lovingdvd
 
Join Date: Jan 2007
Posts: 246
Success!!

I'm happy to report that the custom adapter worked!! The hum is now gone and bass is unaffected (at least by ear - haven't rechecked with REW but not planning to).

Funny thing is that when I first turned it on it was humming pretty good. My initial thought was "not good". Then I remembered I still had the cheater plug on that I used to test for the ground loop.

When I removed the cheater plug the hum was gone. I don't know the theory about how this fix works but it seems logical that having the cheater plug in with this new cable would then "reverse" the situation and bring the hum back.

Again I want to say thanks to all those who contributed to this thread, idea and a special thanks to Wayne for offering to build the cables. I can't say I'm proud of my solder job - but hey, it works!
lovingdvd is offline  
post #103 of 330 Old 03-24-07, 02:58 PM
Elite Shackster
Bob
 
Join Date: Apr 2006
Location: Shueyville, Iowa
Posts: 999
Send a message via AIM to bobgpsr
Re: Success!!

Quote:
lovingdvd wrote: View Post
but hey, it works
Just the "+" and the "-" used to feed the input of the BFD with the shield ground input to the BFD left open? So you had the same good results in doing this that I did.
bobgpsr is offline  
 
post #104 of 330 Old 03-24-07, 05:15 PM
HTS Senior Moderator
 
Wayne A. Pflughaupt's Avatar
 
Join Date: Apr 2006
Location: Corpus Christi, Texas
Posts: 9,177
Send a message via Yahoo to Wayne A. Pflughaupt
Re: What solution do folks use for the dreaded BFD hum?


Just now seeing your new posts, Ric. For some reason my e-mail notification is spotty these days. Happy that you were able to sub an XLR for that crummy Radio Shack plug!

Quote:
Just one question remaining - how am I supposed to wire the shield of the RCA to the proper pin on the TRS or XLR?
After you unwrap the braiding, you can twist it all together, like this:


What solution do folks use for the dreaded BFD hum?-p2170107-.jpg

What solution do folks use for the dreaded BFD hum?-p2170108-.jpg


At that point I would cut the shield fairly short (tin it first) before soldering it to Pin 3. Since it doesn't have any protective insulation, you don't want it shorting out somewhere:


What solution do folks use for the dreaded BFD hum?-p2170138-.jpg


Regards,
Wayne



To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
|
To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.

Wayne A. Pflughaupt is offline  
post #105 of 330 Old 03-25-07, 07:28 AM
Shackster
tbrooke
 
Join Date: Aug 2006
Posts: 13
Re: What solution do folks use for the dreaded BFD hum?

I've had my BFD for a while with no hum problem but I connected up my cable and I have the dreaded hum. The BFD is near my sub amp and actually moving it a little helps but still some hum.

I have followed this thread and am I correct in thinking that all I have to do to solve the hum problem is make some of these XLR thingies?

It ssems with all the hum discussion on this forum an enterprising solderer would make some BFD connectors - Since no one has I guess I'll break out the soldering iron and make my own.

Tom
tbrooke is offline  
post #106 of 330 Old 03-25-07, 09:07 AM
Senior Shackster
lovingdvd
 
Join Date: Jan 2007
Posts: 246
Re: What solution do folks use for the dreaded BFD hum?

The only thing I'm not particularly happy about with my custom made cable is that I didn't know how to do anything special to prevent someone from pulling on the cable and pulling the solder leads right off or having them break off (more likely).

With a smaller wire I would have just made a knot in the inside. How can I go about adding something to make it more "tug proof"?
lovingdvd is offline  
post #107 of 330 Old 03-25-07, 02:04 PM
HTS Senior Moderator
 
Wayne A. Pflughaupt's Avatar
 
Join Date: Apr 2006
Location: Corpus Christi, Texas
Posts: 9,177
Send a message via Yahoo to Wayne A. Pflughaupt
Re: What solution do folks use for the dreaded BFD hum?


Typically XLR’s have built-in strain relief. Some have a pair of screws 180 degrees apart at the end of the barrel that you can tighten down. Neutrik XLRs (the ones in the pictures I posted before) have a built-in collar that clamps down on the cable when you screw the barrel on.

The soldered connection is very robust – it’s not going to break free. The wires will break before the solder gives up.

Regards,
Wayne



To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
|
To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.

Wayne A. Pflughaupt is offline  
post #108 of 330 Old 03-25-07, 06:51 PM
Senior Shackster
lovingdvd
 
Join Date: Jan 2007
Posts: 246
Re: What solution do folks use for the dreaded BFD hum?

Oh ok thanks Wayne, so that's what that little plastic piece does inside of the XLR. Nice!
lovingdvd is offline  
post #109 of 330 Old 11-18-07, 02:08 AM
Shackster
Rich
 
Join Date: Nov 2007
Location: OH
Posts: 39
Re: What solution do folks use for the dreaded BFD hum?

Quote:
brucek wrote: View Post
Yeah, the problem there is two-fold. Many of these baluns pass the ground through on one side. You have to get the kind that uses no ground pass-thru. It needs to be checked with a meter. The other problem is the bandwidth. Many of these baluns only pass TV signals and don't pass the CATV full bandwidth.

The best solution would be to use a in-line transformer on the CATV cable that passed at least 1GHz and those are expensive, so the capacitive solution is the next best so as to block the DC current, yet pass the bandwidth for CATV AC signals.

Here's a ISO-MAX VRD-1FF Cable TV Ground Isolator ground break solution that you would put at the STB as the cable enters. It should do the trick I would think. A bit expensive, but that's what it takes...

brucek
brucek,

Can I install this where the cable feed enters the house, prior to the first splitter the feed is connected to, instead of at the STB? Doing it at the point it enters the house would correct the problem for all TV's in the house as well as for my cable modem. Would there be anything wrong with doing it this way?

I plan on adding an XBOX 360 in the near future. It will be connected to my home network and I don't want to have the same problem with the XBOX 360 causing this problem after I fix it at the STB.

Thanks,

-Rich


To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
RazorX is offline  
post #110 of 330 Old 11-18-07, 08:16 AM
Elite Shackster
brucek
 
Join Date: Apr 2006
Posts: 7,514
Re: What solution do folks use for the dreaded BFD hum?

Quote:
Can I install this where the cable feed enters the house, prior to the first splitter the feed is connected to, instead of at the STB?
Yeah, but be sure to install it after (downstream) from the point where the cable itself is grounded (located inside or outside the house - if at all).

brucek
brucek is offline  
Reply

Bookmarks

Tags
bfd , dreaded , folks , hum , solution

Quick Reply
Message:
Options

Register Now




PLEASE COMPLETE ALL REQUIRED FIELDS BELOW... THANKS!

REQUIRED FIELDS ON THIS PAGE
YOU MUST COMPLETE ALL OF THESE

Username
Password
Confirm Password
Email Address
Confirm Email Address
Random Question
Random Question #2




User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
PLEASE READ BELOW PRIOR TO ENTERING AN EMAIL ADDRESS!

ATTENTION!

YOU MUST ACTIVATE YOUR ACCOUNT!

Activation requires you reply to an email we will send you after you register... if you do not reply to this email, you will not be able to view certain areas of the forum or certain images... nor will you be able download software.

AN INVALID EMAIL ADDRESS WILL CAUSE YOUR ACCOUNT TO BE DELETED!

See our banned email list here: Banned Email List

We DO NOT respond to spamcop, boxtrapper and spamblocker emails... please add @hometheatershack DOT com to your whitelist prior to registering or you will get nowhere on your registration.


Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML is not allowed!
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 


For the best viewing experience please update your browser to Google Chrome