Mission Impossible 5.1 Removing the Buzz

Sumerian

More I get into this hobby more I hear things I never heard before that include the hisses the buzzes and imperfections.

Anyhow I have buzz coming from my front speakers.

They are connected to Cary SLP05 Preamp which in turn is connected to my receiver through HT Bypass.


when Cary is in Pre Amp mode there is no noise what so ever. Speakers buzzes only when the Pre Amp is in HT mode so the noise is coming from the receiver.

I unplugged components one by one and found that Comcast Cable box is what making most of the buzz.
Disconnecting the input cable to cable box stopped the noise so it is not the cable box that are creating the buzz but the signal that is coming in to the box.
I have this monster spike protector which also has the option to clean the cable connection so I connected the cable directly to monster spike protector and the output from monster to cable box.
This has reduced the buzz significantly.

But I still have some buzz coming out from right front speaker not much from left front speaker I can only hear some buzz when keep ear close to it.
But the right front speaker is annoying me mostly when there are any silent scenes I can clearly hear the buzz.

I tried disconnecting the components again from receiver nothing is helping this time.

At this time I am suspecting the MIT RCA cable or the power in my home is not clean any thoughts?

since it is significant in only one speaker I am suspecting the unusual suspect. any ideas?

F1nut

Is it a buzz or a hum?

Sumerian

F1nut wrote: »

Is it a buzz or a hum?

Ok just read the differences between hum and buzz.

the noise coming from my speaker is mostly Hum mixed with buzz , yes I hear em both but hum is prominent.


When I say hum I meant the noise that comes out, if the other end of the speaker terminal (before amplifier) is touched by hand (May be ground loop noise?)

Sumerian

Hurray!!! Humm is gone Buzz is still there.
OK after reading further I found this is ground loop issue... So I used the ground lift switch on amp which removed the hum but I still have the buzzing sound coming from both the speakers

Zentish

It seems that the cable ground is introducing a ground loop into your system. The ground potential of the cable is different from your 110vac home wiring and current is flowing through your system.

You've isolated the problem which is great, but fixing the problem is likely going to require you to lift the ground on your whole system which means that you stop grounding all your gear and use 2 prongs instead of 3. That's the only way I know how to do it unless somehow you can convince comcast to fix their ground.

Sumerian

Zentish wrote: »

It seems that the cable ground is introducing a ground loop into your system. The ground potential of the cable is different from your 110vac home wiring and current is flowing through your system.

You've isolated the problem which is great, but fixing the problem is likely going to require you to lift the ground on your whole system which means that you stop grounding all your gear and use 2 prongs instead of 3. That's the only way I know how to do it unless somehow you can convince comcast to fix their ground.

I got the hum issue resolved with the help of ground lift but I have this buzz.
I disconnected the cable completely but it is still there both fronts and center has this buzz

voltz

When I 1st hooked up my WOO WA3 head phone amp I had both problems, it was a combination of ground loop & 1 bad tube, but I had several pairs of 6dj8's on hand and replace my 7308's it was all quiet

not sure if this relates to your buzz. cause mine was more like 2 hum's (if that makes sense)

Sumerian

voltz wrote: »

When I 1st hooked up my WOO WA3 head phone amp I had both problems, it was a combination of ground loop & 1 bad tube, but I had several pairs of 6dj8's on hand and replace my 7308's it was all quiet

not sure if this relates to your buzz. cause mine was more like 2 hum's (if that makes sense)

My tube pre amp is in HT by pass mode so basically no bad tubes at play.

Good thing is if I turn on the Pre amp and put it in Pre amp mode every thing becomes pin drop silent at least I can enjoy my 2 channel with out any buzz or hum.

tonyb

Buy a 2 buck cheater plug and put it on the AVR.

voltz

Didn't this solve Pycroft problem when he took Tony's advise and used the cheater plug?

http://www.polkaudio.com/forums/showthread.php?160427-Damn-ground-loop-sorry-can-t-diagnose-myself-(

I thought I'd read something like this before.

Sumerian

tonyb wrote: »

Buy a 2 buck cheater plug and put it on the AVR.

So its like lifting the ground up on AVR right? isn't unsafe to remove ground of all these components

tonyb

Sumerian wrote: »

So its like lifting the ground up on AVR right?

Yeah...it's a simple plug available anywhere, takes a 3 prong cord and converts to a 2 prong...lifting the ground without having to screw with the cable itself.

Sumerian

tonyb wrote: »

Yeah...it's a simple plug available anywhere, takes a 3 prong cord and converts to a 2 prong...lifting the ground without having to screw with the cable itself.

Is it really safe to take ground off all this equipment?

Sumerian

voltz wrote: »

Didn't this solve Pycroft problem when he took Tony's advise and used the cheater plug?

http://www.polkaudio.com/forums/showthread.php?160427-Damn-ground-loop-sorry-can-t-diagnose-myself-(

I thought I'd read something like this before.

Thanks for that.....lots of information

Sumerian

tonyb wrote: »

Buy a 2 buck cheater plug and put it on the AVR.

Just noticed my avr has only two prongs...No need of any plugs.

westmassguy

It sounds like you may still have a ground plane differential. It's not pretty, but the simplest method to ensure all component chassis grounds are at the same potential, is to install a separate ground lead connecting each component to the other. An 18 or 20 gauge wire can be used. Your preamp and receiver should already have a ground lug. The other components may not, so you'll need to use one of the chassis screws. Daisy chain the wire from one component to the next. If that doesn't work, the receiver is the likely culprit.

tonyb

Sumerian wrote: »

Just noticed my avr has only two prongs...No need of any plugs.

Then there must be another component in the chain with a 3 prong plug....or switch out the IC'S going from the receiver to the pre. Since the buzz is gone with just the pre in the mix, look from the pre back.