New amp + cable box = feedback. Ground Loop? (Plus, general advice/opinions.) - AVS Forum | Home Theater Discussions And Reviews
Forum Jump: 
Thread Tools
post #1 of 2 Old 03-15-2011, 05:57 PM - Thread Starter
cheeksmcnasty's Avatar
Join Date: Mar 2011
Posts: 1
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Just bought a SpeakerCraft BB275 amplifier to power a pair of Vienna Acoustics Mozart Grands (4ohm); other components include: Time Warner HD cable box, Yamaha RX-A700, PS3, Toshiba 1080 120hz 42" LCD, Bose VCS-10 center channel, desktop computer with and HDMI out.

PROBLEM: Feedback, which did not occur prior to introducing amp, when the cable box and amp are both connected. No feedback from computer audio, unless cable box HDMI is connected to receiver.
The amp is plugged directly into the nearest outlet, the cable box is plugged into a power strip from another outlet on the same wall, still get feedback when each is connected to either plug on outlet.

Anything else need to be done to diagnose this issue?

General Questions:
-I have Key Digital Black Bull Series, Ethereal and AudioQuest Cinnamon HDMI cables, should I return any of them?
-Need a sub-woofer, suggestions (inexpensive, small/medium room)?
-I mostly use system for music from my computer, FLAC/lossless/320kbs, Winamp (a few days into J. River Media Center trial). Computer has an HDMI port but audio card is stock. Should I look into any upgrades here?
-Comments/opinion re: SpeakerCraft BB275 amp?
cheeksmcnasty is offline  
Sponsored Links
post #2 of 2 Old 03-17-2011, 02:18 PM
Senior Member
dealer6871's Avatar
Join Date: Dec 2006
Location: Brunswick Hills, Ohio
Posts: 324
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 11 Post(s)
Liked: 16
My setup includes a blu ray, hd-dvd, time warner cable box and redbook player connected to a Krell processor and Cary Cinema 5 amp. The cable box, blu ray and hd-dvd player are conected direct by HDMI to a Pioneer Kuro Plasma. I was getting a hum through my B&W speakers when watching movies. The hum would increase as I turned up the volume. I started eliminating components with no luck. Even tried switching out power cables and floating the ground on the amp by removing the center pin.

I went to the Parasound website to pull one of their on line amp manuals. Under trouble shooting and hum they made suggestions on eliminating hum. The last was to install a Xantech 634-00 Ground breaker on my cable line. Installed it where my cable goes into the wall and no more hum. Couldn't believe it. The sound also improved. Guessing not having the hum in the background made a difference. Thanks to Parasound for solving a really annoying problem.

I'm not saying this will stop your problem, but it may be worth a try.
dealer6871 is offline  
Sponsored Links
Reply Receivers, Amps, and Processors

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

Forum Jump: 

Posting Rules  
You may not post new threads
You may not 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 code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off