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Parasound Halo Integrated Buzz/Hum

Hi all. I bought a Parasound Halo Integrated last week and discovered there is a faint low frequency buzz coming from my speakers from all inputs except the home theater bypass (more on that below). In a completely silent room I can hear it from my listening position about 8ft away from the speakers, but it's not very loud at all. After a quick Google search and some reading, the most likely cause seems to be a ground loop issue.

Unfortunately, I am not sure if it is as simple as that. I disconnected all inputs and plugged it in an outlet with no other devices connected. I also moved it to a different outlet in my apartment, again with only speakers connected, and it still buzzes. Different model speakers have been tested as well.

The buzz only comes from the speakers, not from the amp itself or if headphones are plugged in. This integrated amp has home theater bypass inputs and there is no buzz when this input is selected. However, if I connect my AVR to these inputs, there is a buzz. This buzz can also be heard through headphones connected to the Parasound. Unlike the buzz from other inputs, this buzz does not increase when I increase the volume.

My apartment is in an old building, which in all likelihood had its wiring redone over the past decade or so. I used a 3 wire receptacle tester on some of the outlets. It indicates there is an open ground in my living room (something I should probably bring to my landlord's attention!), but other outlets appear to be wired correctly. The buzz is there regardless of what outlet I use, however.

The amp was bought from an authorized dealer and I am still under warranty, so I can certainly get it replaced or repaired. Before I do that, however, I would like to make sure I have exhausted all of my options. Do any of you knowledgeable folks have any idea if I am missing something? 
tod_
audiozen
831 posts
 
It appears 20 years later that Parasound is still having the buzz humming problem with their amps.. Having owned two Parasound amps and three Parasound Preamps since 1992, here is what is more than likely the problem. Noise coming from the transformer due to faulty grounding during assembly at the plant in Taiwan. This was a very severe problem
with their biggest stereo amp ever, the HCA-3500, which had dual transformers. Two of my audio friends owned the 3500 back in the early nineties, at the time I owned the HCA-1200 which didn't have that problem. Both my friends amps had the buzz, humming problem from their transformers and had to be sent back to Parsound to properly ground the transformers. The same problem was also experienced with audio reviewers at the time with the 3500, the amp was eventually put out of production.

erik_squires
16,041 posts
 
I have owned 3 separate pieces of Halo gear and never had a hum/buzz issue.

One thing to try, disconnect any Cable TV/Antennas. They are the most common source of ground issues. There's good cheap fixes if that turns out to be the case.

Best,

E
oddiofyl's avatar
oddiofyl
3,785 posts
 
Cable is the number cause for sure....  but i also had a weird buzz /hum I could not put my finger on.   It turned out to be one of those scent warmers that my wife plugs in all over the place....
audiozen
831 posts
 
I would borrow another amp from a friend or store, plug it in to the same outlet, if theres no buzz or humming coming from your speakers, than its probably a ground defect in the integrated. 
helomech
1,670 posts
 
I had a Halo Integrated and experienced the same issue. I used 6 different pairs of speakers with the amp, in addition to different outlets, cables and source components. I also checked the ground points inside the amp. The noise always remained at the same level, however, it was low enough that it was rarely noticeable during playback.

 The only other amps I’ve had in my system that produced similar noise were all 3 Rogue Audio integrateds. My experience led me to believe that it’s in the nature of the H-Int’s design, not a QC issue.
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