Help: humming from Halo A51

[bcgator]

Hi all,

Well, got my Halo A51 home, got it hooked up (using Sidewinder RCA cables) to my Onkyo 701 receiver and B&W 805 Signature speakers, and I've got buzzing from all speakers.

The ground toggle is set to "lift", all connections are tight and secure and proper. I've tried plugging the amp into multiple outlets, and/or a surge protector, and I can't make the buzzing stop.

It's a pre-owned unit, and I listened to it at the previous owners house so I know the unit works. Something in my setup must be causing it.

In case this is important info, the amp is in an enterntainment center with a TV set, digital cable box, and the Onkyo receiver and Universal DVD player.

Anybody got any ideas?

Thanks,
BCGator

[bcgator]

Ok, made a little progress: as soon as I unplugged the cable tv from the wall, the buzzing disappeared. So that's my culprit. Apparently there's some Xantech Ground Breaker device that I can install to filter out cable noise. I'm going to bed, and will tackle it in the morning.

Any feedback or comments still appreciated.

BCGator

[SpOoNmAn]

99% of the time, its the damn cable.

Pass that lesson along to every single person you know :T

[nicholtl]

From what I know, the ground lift switch isn't supposed to be set to "lift" by default. Only if there is a problem should that option be engaged...

It also seems you've found the culprit. Hopefully that's all it is. The coax cable.

Just a side note: running an A51 and B&W speakers... I think your setup deserves better than QC Sidewinders. If anything, their King Cobras, Cheetahs, or Sky's. Or better yet, go balanced (assuming your Onkyo accepts XLR's).

[mikepinkerton]

When I bought my A51, I had the exact same issue except it was with the satellite box. Using the lift switch helped a little, but not enough, I still got hum.

For cable, you can get a decoupler to "break the circuit" but still pass through the signal. Search for "decoupler ground loop" on google and you should find a lot of info. The problem is that this doesn't work for satellite, which needs to pass the DC signal for control of the LNB's. I ended up using a 12ga wire (extra speaker cable) to tie the A51 to my sat box, thus unifying the grounds and defeating the loop. No hum, wonderful amp!!!!

Halos are just sensitive to group loop issues, but there's plenty of resources in your situation to fix it for about $20 or less. Whatever you do, DO NOT use a cheater plug (3prong -> 2prong adaptor) as a long term fix. This is just asking for serious trouble. Fix the problem the right way.

-Mike

[bcgator]

Mike, thanks for the info. I actually was able to eliminate the hum by running my cable coaxial line through the surge supressor I'm using for DVD player, cable box, etc. It has cable in/out plugs, to send the cable line through the surge supressor. Believe it or not, that did the trick.

BCGator

[mikepinkerton]

Awesome, enjoy your new amp!!!!

-Mike

[Docray1]

Cheater Plug Question

My Halo A21 exhibits ground loop buzzing as well unless I use a "cheater plug" - which was suggested by Parasound technical support! mine is plugged into a Panamax surge suppressor; am I still at risk for some tragic event? What type of ground loop isolators have other members had success with? My noise seems to arise primarily, but not entirely from my cable TV line. I never had any issue with any amps before my Halo. The "ground lift" switch is of no help at all. Thanks in advance!

[Marshal]

Check your manual and find troubleshooting section fro noise from cable TV. Buy Xantech ground breaker for $10 and your problem is solved.