Distortion (terrible buzz) running amp off receiver (1 Viewer)

[Chris M34]

I have a Sony STR DN 1060 that I have run an AudioSource AMP310 off of using a speaker level to line level adapter because the receiver does not have preouts. When I plug the HDMI from the cable box into the receiver I get a terrible loud hum/buzz noise. Anybody know what this could be?

 

[JohnRice]

It's probably a ground loop, which is extremely common when you have an electrical connection (the hdmi) between the cable box and receiver. I've found it's virtually impossible to eliminate without eliminating that electrical connection between the cable box and TV. One option is if the cable box has an optical audio output, connect that to the receiver and run the hdmi directly to the TV.

 

[John Dirk]

Almost certainly a ground loop. You can try one of these for the cable box.

See on Amazon

See on Amazon

 

[JohnRice]

FWIW, I've tried all those things in the past, and while they could reduce the hum, nothing ever eliminated it. It hasn't been a problem for me in quite some time, because I haven't had conventional cable in about 20 years. It's inherently not a problem with streaming based TV, which is what I have now.

 

[Chris M34]

Thank you guys, so I just upgraded TV’s to a 4K and In turn had to get a 4K box which no longer has the optical cable which I was previously using and didn’t get that buzz unless I had 2 HDMI’s plugged at the same time. I’ll try the buzz eliminators and see if that works

 

[Chris M34]

The other question I have that may or may not matter is if I used the hum elimintor would I plug the AMP or cable box into it?

 

[JohnRice]

A quick thing you can try for free is that your TV should have an optical audio output. Connect it to the receiver instead, with the hdmi from the cable box going directly to the TV. Depending on the TV, it might mix down the audio to two channel, but most TVs today will pass through at least Dolby Digital. You might have to look at the digital audio output options on the TV to see what works best.

The goal is for there to be no electrical connection between the cable box and the receiver.

 

[Chris M34]

Haha that’s funny I actually ran across that option before I read this and it does work. I think the real reason I’m getting the hum is because my amp is run through the line level adapter. For some strange reason if I run the PS5 I have to unplug the Cable HDMI and then plug in the PS5 HDMI. If I run them at the same time it also gets the buzz

 

[JohnRice]

I think the real reason I’m getting the hum is because my amp is run through the line level adapter.

It's essentially caused by the cable connection, but can be made worse by the amp, since it has a grounded plug. The only way I know of to eliminate it is to eliminate any electrical connection between the cable box and the receiver. The easiest way to do that is to use optical. For instance, if you used a fiber optic hdmi cable between the cable box and the receiver, that should also fix it.

 

[Chris M34]

Oh wow I didn’t even realize there was a fiber optic HDMI cable. How’s the price range on those?

 

[JohnRice]

Oh wow I didn’t even realize there was a fiber optic HDMI cable. How’s the price range on those?

That would be a waste, probably. They're intended for long runs and start at around $200.

 

[JohnRice]

Oops, I guess they've gotten cheaper. HERE'S a 2M for $23. I don't know about brands on those, but might be worth a try for that price.

 

[Chris M34]

Yeah I see some cheap ones but not sure that’s what I’m looking for. The Buzz off got delivered so I’ll be trying that when I get home. I’m assuming that I should plug the cable box into that?

 

[JohnRice]

Yeah I see some cheap ones but not sure that’s what I’m looking for. The Buzz off got delivered so I’ll be trying that when I get home. I’m assuming that I should plug the cable box into that?

Yeah, see my post above. That would go between the cable box and the receiver, and should allow you to connect everything normally. The important thing is to be certain there is never any electrical connection between the cable box and the receiver.

Also, be aware fiber hdmi cables are directional. Meaning, there is a source side (cable box) and a destination side (receiver) to the cable. If you connect it the wrong way, it won't work.

 

[Chris M34]

You are the man! I’m a little confused when you say make sure there is no electrical connection between the 2. The HDMI causes that connection?

 

[JohnRice]

You are the man! I’m a little confused when you say make sure there is no electrical connection between the 2. The HDMI causes that connection?

It's the electrical connection between the cable box and the receiver that causes the ground loop. That was originally caused by the traditional hdmi cable between them. Since a fiber hdmi cable has no electrical connection (it doesn't have any wires in it), it should also eliminate the ground loop. Same as connecting the cable box to the TV and then using optical to the receiver. Does that makes sense?

 

[JohnRice]

I've never tried this solution, but it should work. I don't have wired cable anymore, so I can't try it.

 

[JohnRice]

What I don't know is if the eARC feature of the cable is electrical. It might be, and if it is, you'll probably still get the ground loop.

 

[Chris M34]

Nice, I just read up a little on it. I’m pretty sure your right on the ARC because my previous box setup I would have to unplug the cable box HDMI to run the ARC PS5 and Vice versa but that’s better than a new receiver!

 

[Chris M34]

I've never tried this solution, but it should work. I don't have wired cable anymore, so I can't try it.

What do you just stream now?