# Eliminating 120 hz buzzing



## Brandon Briesath (Jan 7, 2019)

Had to re register. Been a long time since I’ve been on here.

Trying to eliminate a very annoying 120 hz buzzing sound coming through my setup. I’ve tried tons of things, new surge protectors, different outlets, hum x, etc. it’s a buzz that come on every 6-8 seconds, buzzes for a few then goes off, never stopping.

My setup is very complex. 
Yamaha cx5000 pre
Parasound amp a21
Parasound pre p7
Behringer fbd 
Dual subs
Custom built pc with 200 watt external power supply
Schiit dac
Directv box
Sony ps3
Outlaw 7 ch amp for surrounds and zone speakers

I’ve tried unplugging cables many times and can’t seem to locate the root of the problem.

Any suggestions on where to begin?
Thanks.


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## Wayne A. Pflughaupt (Apr 13, 2006)

Try unplugging the DirecTV box from the system.

Regards,
Wayne


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## Brandon Briesath (Jan 7, 2019)

Wayne A. Pflughaupt said:


> Try unplugging the DirecTV box from the system.
> 
> Regards,
> Wayne


This was one of the first things I tried and nothing changed. Im guessing its a ground loop issue but honestly don't know how to remedy it.


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## Wayne A. Pflughaupt (Apr 13, 2006)

The antenna lead? Because that’s where the problem would be, not the audio connections.

Ground loops are caused by different paths to ground. Often CATV or satellite do not have their ground lead go all the way to the house electrical ground stake, so that’s why I recommended disconnecting it.

Next, make sure all the system components are plugged into the same electrical circuit.

If that doesn’t help, disconnect and unplug everything in the system except the pre-amp, amp and speakers. Then add components back in one at a time.

Regards,
Wayne


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## Brandon Briesath (Jan 7, 2019)

Wayne A. Pflughaupt said:


> The antenna lead? Because that’s where the problem would be, not the audio connections.
> 
> Ground loops are caused by different paths to ground. Often CATV or satellite do not have their ground lead go all the way to the house electrical ground stake, so that’s why I recommended disconnecting it.
> 
> ...


So unplug the antenna/satellite feed coming into the directv box? I will try this again and see. Im pretty sure I've ruled this out already but will double check. 

I recently plugged all of my components into the same outlet, again trying to rule things out. I will do more trouble shooting this afternoon. I have a remodeling project starting this spring. Can something be done at this time via electrical work to remedy this issue if I cannot find the culprit?
Thanks for your help!


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## Wayne A. Pflughaupt (Apr 13, 2006)

Brandon Briesath said:


> I have a remodeling project starting this spring. Can something be done at this time via electrical work to remedy this issue if I cannot find the culprit?


Have one or two dedicated circuits put in. If more than one, make sure they are on the same phase.

Regards,
Wayne


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## Brandon Briesath (Jan 7, 2019)

Wayne A. Pflughaupt said:


> Have one or two dedicated circuits put in. If more than one, make sure they are on the same phase.
> 
> Regards,
> Wayne


Gotcha! I had thought about doing this already. So one dedicated circuit/breaker in the panel just for my gear in that setup correct? Is there any chance that the grounding on the panel is the culprit in which a dedicated circuit wont help?


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## Wayne A. Pflughaupt (Apr 13, 2006)

I don’t see how that would be possible. The electrical grounding system is pretty simple, if it’s done correctly. So I guess the key phrase there is “done correctly...”

Regards,
Wayne


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## Brandon Briesath (Jan 7, 2019)

Wayne A. Pflughaupt said:


> I don’t see how that would be possible. The electrical grounding system is pretty simple, if it’s done correctly. So I guess the key phrase there is “done correctly...”
> 
> Regards,
> Wayne


The house was built only 10 years ago and I don’t invision the grounding to be done incorrectly. I suppose it’s a possibility but unlikely.


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## Brandon Briesath (Jan 7, 2019)

Well I unplugged the satellite feed (rg6 cable) coming into the directv box and unplugged it’s power source and nothing changed. I also confirmed the outlet that all my equipment is plugged into is a dedicated one with nothing else on it. Still that hum/buzz.

I’ll try leaving just the amp, preamp, speakers connected and process of elimination from there.


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## Brandon Briesath (Jan 7, 2019)

One discovery which I hope is relevant. So my Parasound P7 has HT bypass which I of course use in my setup. When it’s in bypass, meaning I’m using the Yamaha CX-A5000 for volume, sources, etc, the buzz is audible like I’ve described. As soon as I switch the Parasound P7 to any source coming into it other than HT bypass, the buzz disappears completely. So for example, if I switch the P7 to my music input coming from my Schiit DAC, the buzz is gone!

Does this help narrow things down?


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## RTS100x5 (Sep 12, 2009)

Hi Brandon - its a process of elimination really

Is is in all speakers or just subs ??
1. disconnect all sources - is it still humming
2 . disconnect subs signal cable from subs 1 at a time.. is it still buzzing through speakers


If it's in all speakers probably an issue with your pre amp - unless its related to one particular source...


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## Brandon Briesath (Jan 7, 2019)

RTS100x5 said:


> Hi Brandon - its a process of elimination really
> 
> Is is in all speakers or just subs ??
> 1. disconnect all sources - is it still humming
> ...


I agree. Rather than disconnecting all of the sources, then adding them back one by one, I chose another path simply to avoid forgetting how everything was connected

I disconnected one source at a time, listening for the hum, then reconnecting it and moving on to the next source. Will this process work too? If so, then I basically tried what you suggested already. I removed every source at some point, even the subs, nothing changed.


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## RTS100x5 (Sep 12, 2009)

Kinda of confusing why you are using 2 pre amps ?


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## Brandon Briesath (Jan 7, 2019)

RTS100x5 said:


> Kinda of confusing why you are using 2 pre amps ?


The Yamaha is for Audio and Video. Such as Movies (Blu ray, Directv, etc). The parasound P7 is for audio only. The reason the P7 has HT bypass is so one can incorporate a Stereo (music only) preamp into their setup while utilizing their receiver/processor (in my case the Yamaha CXA5000) and existing amps. Its complicated yes, but very typical.


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## Brandon Briesath (Jan 7, 2019)

Here are some wiring diagrams.....


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## RTS100x5 (Sep 12, 2009)

Interesting, though I fail to see the need for the P7 ...Usually in that scenario - Im just sending the yamaha pre outs directly to the 2ch amp...in any case if your switching the HT bypass on/off and the hum goes away then I suggest therein lies the problem , but you probably know that...


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## Brandon Briesath (Jan 7, 2019)

RTS100x5 said:


> Interesting, though I fail to see the need for the P7 ...Usually in that scenario - Im just sending the yamaha pre outs directly to the 2ch amp...in any case if your switching the HT bypass on/off and the hum goes away then I suggest therein lies the problem , but you probably know that...


The P7 is NOT necessary but sure sounds better than running a quality 2ch source through my Yamaha. A dedicated 2ch preamp makes a big difference in most systems, but again YMMV

I have reached out to parasound to get their take on this. Its also possible the buzz is coming from the Yamaha into the P7. Stay tuned.


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## Brandon Briesath (Jan 7, 2019)

So I think I fixed it! The Parasound A21 amp has two options for Input, balanced and unbalanced connections. I removed my balanced XLR cables from it and the p7, and replaced the pair with good old RCA cables, flipped the switch on back of the A21 and guess what, the buzz is nearly inaudible!!

I have no clue why this fixed it but so far so good


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## Wayne A. Pflughaupt (Apr 13, 2006)

Wow, that’s startling. If anything, I’d have expected going from unbalanced to balanced would have made a difference.

Regards,
Wayne


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## Brandon Briesath (Jan 7, 2019)

Wayne A. Pflughaupt said:


> Wow, that’s startling. If anything, I’d have expected going from unbalanced to balanced would have made a difference.
> 
> Regards,
> Wayne


I agree, very unusual. I posed the scenario to Parasound to get their input.


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## SoundManDale (Oct 31, 2013)

Get Iso-Max from Jensen Transformers.
Google it


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## henry97071 (Nov 28, 2011)

You have a ground loop via the multiple pieces of equipment that you have plugged in. Use unpolarized plugs in all except one pice of equipment (power amp maybe).


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## triplington (Oct 24, 2009)

I don't think you have a ground loop, I think you have a broken ground, probably in 1 of your cables. Ground loops tend to buzz continually not every 6-8 seconds, but something else in your house might be cycling noise onto the neutral that a badly grounded signal path could pick up on. Try changing cables and if you have a DVM, check continuity.


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## fokakis1 (Feb 29, 2012)

Wayne A. Pflughaupt said:


> Wow, that’s startling. If anything, I’d have expected going from unbalanced to balanced would have made a difference.
> 
> Regards,
> Wayne


I agree. I just removed an unbalanced cable and replaced it with balanced. I had a very faint hum that is now gone.


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## RLouis (Jan 20, 2010)

Two things that will help remove ground noise, if not completely eliminate is 1) Get a couple of those old-school 2-to-3 prong plug adapters. These effectively lift the house power ground from anything plugged into it without changing any house wiring or having to cut the ground pin off your 3 prong plugs. Many appliances and power supplies just dump extra voltage right into the common house ground causing excessive ground ckt noise. Start with your source components first then also try on amp/s. The adapter are only $1-$2 each and won't limit current delivery at all. And #2) Get a good (real) A/V power conditioner for your source components. There's often good deal on CL. This will costs more but will also certainly help eliminate ground noise. Skip the power strips that claim to have noise filtering. Then #3) Combine both >> put the 2-3 prong adapter on the plug of the power conditioner that all your source components are plugged into.


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## wantAvote (Dec 2, 2018)

I thought i would add a few extraneous thoughts for consideration. 

Although single wire unbalanced interconnects are inferior to three wire balanced interconnects in their ability to transfer cleaner signals over longer distances and usually neither are problematic in small home theaters. 

Problems can occur when using all single wire unbalanced interconnects throughout the system and later introducing a single pair of three wire balanced interconnects is potentially problematic. While the signal and chase ground wires remain connected throughout the signal path, the signal ground lead and negative ground leads and their effect on components as they are connected only at one end might be looked at. 

The dislocated signal ground lead and negative ground leads will become susceptible to emi and rfi noise as each are in effect (one potentially two connected only at the component) become antenna. Say for instance the computer fan is close enough to cause electromagnetic interference..., i think you all can finish my thoughts here.

Most good computer sound cards compensate for fan (resonant frequency) noise but if your interconnects and speaker wires are problematic and pass too close you may receive extraneous unwanted signals and other interference.

a Clean Ground is critical as is a clean signal transfer. 

I hope you get this figured out - sounds like you've got part of the problem identified.


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## Brandon Briesath (Jan 7, 2019)

RLouis said:


> Two things that will help remove ground noise, if not completely eliminate is 1) Get a couple of those old-school 2-to-3 prong plug adapters. These effectively lift the house power ground from anything plugged into it without changing any house wiring or having to cut the ground pin off your 3 prong plugs. Many appliances and power supplies just dump extra voltage right into the common house ground causing excessive ground ckt noise. Start with your source components first then also try on amp/s. The adapter are only $1-$2 each and won't limit current delivery at all. And #2) Get a good (real) A/V power conditioner for your source compmonents. There's often good deal on CL. This will costs more but will also certainly help eliminate ground noise. Skip the power strips that claim to have noise filtering. Then #3) Combine both >> put the 2-3 prong adapter on the plug of the power conditioner that all your source components are plugged into.


So for any equipment with 2 prong plugs, buy the 3 prong adapters? That’s easy.

Good info here guys, thank you. At least for the moment the issue has been partially resolved. The buzz exists but only if my ear is up against the speaker.


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## Brandon Briesath (Jan 7, 2019)

triplington said:


> I don't think you have a ground loop, I think you have a broken ground, probably in 1 of your cables. Ground loops tend to buzz continually not every 6-8 seconds, but something else in your house might be cycling noise onto the neutral that a badly grounded signal path could pick up on. Try changing cables and if you have a DVM, check continuity.


I’ll be yanking my system out in a few months for a remodel, so I’ll grab some new RCA cables before reconnecting. Will the premium ones from mono price (gold plated) be sufficient? What’s DVM?


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## Brandon Briesath (Jan 7, 2019)

wantAvote said:


> I thought i would add a few extraneous thoughts for consideration.
> 
> Although single wire unbalanced interconnects are inferior to three wire balanced interconnects in their ability to transfer cleaner signals over longer distances and usually neither are problematic in small home theaters.
> 
> ...


So should I just stick with all unbalanced cables then? I do have I believe one set of balanced cables yet going from my DAC to preamp.


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## wantAvote (Dec 2, 2018)

Sorry to take so long to respond. It wasn't long ago any answer to your question would inspire controversy and a long heated discussion.

i'll try to avoid the controversy by suggesting there are XLR/RCA and/or RCA/XLR adapters available. 

Neutrix is a decent product: https://www.alliedelec.com/product/...VzICfCh2qnwBwEAQYAiABEgKVY_D_BwE&gclsrc=aw.ds

I wrote my comment in the early AM hours sorry a bit convoluted and absent description - no proof read...

My understanding of circuit buzz is mostly a result of ground issues and voltage drop/additive issues (e.g. using multiple AC receptacles in a singular AV circuit and/or multiple amps in a singular circuit). Additionally, personally i look for circuit continuity including EM integrity. What I mean is, in every electric circuit, electricity in motion is accompanied with an electromag wave that extends well beyond the wire insulation sheath, right..., possible reason for some acceptable low S/N ratios common common to every electric component? 

..., i am not suggesting you continue a balanced interconnect with adapters rather i would buy a furutech unbalanced interconnect for the sake of continuity.

However, a further consideration might be a very expensive "Ground Boost" from Synergistic Research...., or additional diode rectifier somewhere

You know..., a simple voltage checker (crossed AC line)with a $10 GB GFCI checker might be revealing. Maybe check component AC out lines as well

I hope you find something.


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## Brandon Briesath (Jan 7, 2019)

wantAvote said:


> Sorry to take so long to respond. It wasn't long ago any answer to your question would inspire controversy and a long heated discussion.
> 
> i'll try to avoid the controversy by suggesting there are XLR/RCA and/or RCA/XLR adapters available.
> 
> ...


Thanks for the reply! After more digging and trial and error, it seems as if the stereo pair of RCA wires I ran from my DAC in my main setup to another stereo in our bedroom was causing the hum/static sounds. By unplugging it, problem solved!


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## wantAvote (Dec 2, 2018)

Without looking back thru comments - how/where do you switch from the AVR to your P7. All handled internally in the AVR? Do you power down the P7 when not in use and visa/versa? Where is the DAC located... in your 2 channel sys...


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## wantAvote (Dec 2, 2018)

Thanks


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