ground loop issue with parasound hca-1500

thejck

I am fighting a ground loop issue with an integra receiver and an amp in my theater room. When the amp is just connected to the speakers it sounds fine. When I use the rca interconnects to the receiver there is a low buzz that develops in the speakers. when i turn the receiver on the buzz gets fairly loud.

The loud buzz goes away when i pull the hdmi cable out the back of the receiver. (This hdmi cable is a 25 foot cable that runs into my living room into the back of another receiver.) However the softer buzz remains.

I tried a cheater plug to lift the ground on the amplifier and all my problems including the loud buzz and soft buzz disappear.

If it dangerous to run the amp with this cheater plug? Any other suggestions?

kevhed72

Funny, I just had the same issue with my HCA 2203. Here are a couple things to check that worked to reduce the hum ALMOST to nil.
1. Try unplugging the coax cables coming into the house / room going to the cable box or DVR box. I am assuming you have either a satellite or cable coax signal coming into the house. If this is the source, there are ground loop isolators / filters you can buy. With my ground loop, I switched out the 2coax cables with new ones with 4 screw-on coax connectors. I made sure the best I could that the SHIELDING of the coax was cut flush with the black cable as not to touch the actual screw-on connector. I then ran both new coax cables through an extra Belkin power strip with a coax filter I had. I leave this power strip UNPLUGGED.
2. Try moving / isolating all your power cords from your IC's and speaker cables. I bunched all my power cords and ran to my power conditioner on one side of my gear, and then to try to keep all other cords away from this side of the AV rack.
3. Check if your cable line or satellite lines are properly grounded outside of the house...I hear many times the providers cut corners with grounding the lines properly.

These are just a couple of things to try...as a ground loop can be a PITA.:(

tonyb

I've used a cheater plug for years with no issues. Since the amp is connected to the other gear by cables, it is still grounded. Ground loops occur mostly when there are too many grounds on one outlet. Other things can contribute too such as bad cables,cable tv boxes, etc. Useing the cheater plug is pretty safe imho.

HB27

kevhed72 wrote: »

Funny, I just had the same issue with my HCA 2203. Here are a couple things to check that worked to reduce the hum ALMOST to nil.
1. Try unplugging the coax cables coming into the house / room going to the cable box or DVR box. I am assuming you have either a satellite or cable coax signal coming into the house. If this is the source, there are ground loop isolators / filters you can buy. With my ground loop, I switched out the 2coax cables with new ones with 4 screw-on coax connectors. I made sure the best I could that the SHIELDING of the coax was cut flush with the black cable as not to touch the actual screw-on connector. I then ran both new coax cables through an extra Belkin power strip with a coax filter I had. I leave this power strip UNPLUGGED.
2. Try moving / isolating all your power cords from your IC's and speaker cables. I bunched all my power cords and ran to my power conditioner on one side of my gear, and then to try to keep all other cords away from this side of the AV rack.
3. Check if your cable line or satellite lines are properly grounded outside of the house...I hear many times the providers cut corners with grounding the lines properly.

These are just a couple of things to try...as a ground loop can be a PITA.:(

What he said. Do ONE procedure at a time so you can identify your ground issue. YOUR ground issue will most like likely pop up again IF/WHEN you switch out gear and you'll have a better idea where to look for it in the future.
I've been using two prong plugs for decades on my old tube gear and have no problems. The ground is a safety factor I'd keep if possible. I have used cheaters in the past with no issues and I'm not concerned at all using them. That's just me and I know electronics. I don't recommend it though.

dpowell

Your HDMI cable is likely transmiting the noise from one of your connected components; most likely your cable box.

Consider the ISOMAX VRD-1FF by Jensen. It solved my problem.

cfrizz

tonyb wrote: »

I've used a cheater plug for years with no issues. Since the amp is connected to the other gear by cables, it is still grounded. Ground loops occur mostly when there are too many grounds on one outlet. Other things can contribute too such as bad cables,cable tv boxes, etc. Useing the cheater plug is pretty safe imho.

Agreed Tony. I've been using one for years as well. Nice cheap fix for an annoying problem.

Outfitter03

Thanks for the product suggestion dpowell. I have also had intermittent hum and while it is less frequent now, this is a fairly inexpensive fix to eliminate another potential source.

steveinaz

Another issue that can be a PITA to fix is interconnection of 2-pronged AC components (such as DVD players) to 3-pronged AC components. Sometimes the only way to rid the hum is by using a toslink. I have all my video components isolated from my 2-channel audio for this reason, and my system is dead silent.

dkg999

Ground isolator on the coax feed to the cable box. Usually around $10 to $15 for a decent one. Don't some of the HCA-1500's have a ground lift switch on the back of the amp? I can't easily get to the back of mine to see.

thejck

the hca sereis does not have a ground lift. I have one on my halo amp.
i will check again but I am pretty sure i isolated the coax from the system.
At least I know it can be solved with a cheater plug if I cannot isolate it from the system.

thejck

can these isolators be found locally or do they need to be ordered online? I tried radioshack and they do not have one.

kevhed72

Try Amazon...they have them for cable boxes, but not sure about DirecTV satellite service.

steveinaz

Try to find a used Mondial Magic isolator. They're pricey ($99 new), but very good and won't degrade your picture.

thejck

thanks for your suggestions guys. Apreciate the help on here

sm88

I have a Parasound and it would hum as well. Clipping the ground off a cheaper power cord I was using solved it, same as using a cheater plug.

The alternative, which let me use a normal, grounded plug, was to switch to a digital source. Using an optical cable to your receiver or DAC will break the electrical connection between the source and the rest of your system, for me, using a computer as my player, it solved the issue completely.

thejck

I used to use optical with my old receiver and never had any problems. With the advent of the stupid HDMI all these problems start to appear.

kevhed72

sm88 wrote: »

I have a Parasound and it would hum as well. Clipping the ground off a cheaper power cord I was using solved it, same as using a cheater plug.

The alternative, which let me use a normal, grounded plug, was to switch to a digital source. Using an optical cable to your receiver or DAC will break the electrical connection between the source and the rest of your system, for me, using a computer as my player, it solved the issue completely.

Ehhh, Although I have done this with extension cords and outdoor X-Mas lights in the past to 'git er dunn', I would be squirelly doing this for my amp.
PS Audio make power cords with a removable ground pin.

kevhed72

Just thought I would add a bit more info. for the archives. I was having issues with a couple of my HD DirecTV channels. The Service Tech was just here and discovered my coax cable from the wall to the box was "bad", possibly due to a lightning strike. So he swapped out the cable with a new one with the proper Satellite TV connectors. Previously, I had installed a cable with generic screw-on connectors to eliminate a ground loop originating in the DirecTV feed. The reason I did this was to attempt to NOT have the metallic shielding within the cable touch the connector at any point, as this can cause a ground loop hum.
The tech said only use their connectors, and I believe the guy. Only problem is the hum is now back. So, next move is a power cord with the removable ground pin, due I know my amp is generating the hum. I know this due my previous lower-powered Adcom had only a 2-prong plug and I never had the hum before adding the higher-powered Parasound w/ 3 prong plug. Hope this info. helps others w/ the same issue...

jaritta

Fyi, I had the same hum coming form my speakers while useing a sperate amp, and when i unplugged the coax it stopped. I looked at ground loop isolators and cheater plugs, the easiest fix that i used is if you have an powerstrip with coax in out on it, it will take care of the issue. The problem with the hum(if it is the coax) is that the coax isnt grounded properly....the power strip with the coax in out will do that. I should note that the wall outlet that the power strip is pluged into has to be grounded also. To me this is the easiest fix, and no cheater plugs(no ungrounded components )

PrazVT

Though I already had my cable coax running through the power center, I have yet to hear any humming from the parasound amp - so presumably it's a good preventative measure.