2. home-theater
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Signs of poor electricity in home...?

Ok folks I know pretty much that all homes have crappy power for electronic gear. However my dilemna is that I have continued to have a buzz type sound come from my spkrs whenever amp is powered on. This is the same case with three different amps and a recvr. I just completely disconnected everything and have all the gear everywhere in the living room. This was no small task.
Nht Controller
Nht Power 5
Nht Power 2
Oppo 83
Toshi HDDvd
AudioControl Bijou EQ
Panamax 5500ex
Nht A1 x 2 for bi-amping mains.
Nht X2

I use Signal pwr cables and my own custom made.
Signal, Bluejeans, monster ic's
PS Audio powerport

I have eliminated any cable combo as the culprit and have it narrowed down to the fact that with an amp plugged in, powered on, and just spkr cable connected to a spkr I get this slight buzz/hiss type noise. I mean nothing connectected to amp but what I said...electricity...and spkr cable direct to spkr. It is not the hmmmmmmmm of 60hz...it's a hiss like white noise makes when a tv channel would sign off-air if you are old enough to know what I mean. Anywho...it's bugging me to pieces. I have went to the breaker box in garage and eliminated it being the fridge in neighboring room, etc. Even with the Panamax it still gets noise to the spkrs mid/twtr...mainly mid. Volume has little or no effect on it if you are wondering.

So????? Dirty house power and what do I do. Would having a seperate/dedicated line help? I don't have dimmer lamps or any other of the typical buggers in the ac chain. No tv either as I have a Pj setup which plugs in where I use to have a ceiling fan and installed box/receptacle to pwr it.

I don't hear it if source is playing but sitting idle all 5 spkrs doing this is annoying. Suggestions please.
mnnc
detredwings
162 posts
 
Mnnc have you always had this problem or is it something that just starting happening?

As far as the cheater plug. No it will not hurt it to just plug in your amp into it to check the noise. I would recommend just one amp plugged in with one set of speakers not all your components.

You can also try your surround speakers in the mains positions to verify a possible mismatch as Mlsstl has mentioned. But try only the two connected disconnect the surrounds.

One last thing if you have some headphones trying hooking them up via the same power outlet through your CD player or amp and see if you hear the noise.
mnnc OP
175 posts
 
Detredwings...I have had this problem with all amps. I have current amp plugged in to wall, and using one spkr cable to test main L, C, main R. No preamp connected at this time...amp is solo. I still get the whine/hiss. I am basically bench testing so to speak.

Concerning cheater plug...can I use a 1 male to 3 female type plug which is used for plugging in and powering 3 things from 1 outlet? I have a couple of those around the house for desk lamp/phone charger/etc. It has ability to accept 3 prong plugs but only has 2 prongs to plug in receptacle. That would work for testing purposes would it not?

If I use headphones to test for noise I will have to connect prepro to amp of course which I can do in a moment as this thread is happening in real time almost and I appreciate all the help/advice.
sop1
12 posts
 
What about wireless interference? The speaker wires or components in the amps might be picking up something external in the air. I had a problem with my HDTV pixelating intermittently. Turns out it was a cellphone that was on a frequency that was a close frequency to particular channels and the cable box unit was picking it up. Perhaps some device in your house is not shielded enough, malfunctioning, or too close like microwave oven, cellphone, cordless phone system, a wireless router, satellite dish, near the path of a business microwave communication link.

Another idea is to have your electric main on the outside of the house checked by the electric company. I believe they will come out for free to check this as the core in the box is their equipment. These cores can go bad and if they see the specs are out of normal they will replace it. They will probably put a new one in anyway since they are there already. If they do their job correctly they will also check that you are getting two solid, clean 120 (x2 =240)connections to the house from the pole as part of the call.
mnnc OP
175 posts
 
I did the cheater plug method and extension cord method and results are no fix. Seems like anywhere in the house yields this high freq pitch from mid/twtrs. It is audible from within a foot or two and if you pay close attention in a quiet setting, which I have, you can hear the whining noise from farther away. It is not audible over source playing though.

I think I'll contact the pwr co tmrw and see if they can get a tech out hear.

In the meantime I am going to unplug the router which is at opposite end of house in back spare room/office. House is ranch style and I am next to garage in living rm.

If after all possibilities are eliminated and I still have this are there some things I could do to lessen it like better shielded spkr wires or ic's. My bluejean cables are known for the ability to reject emi/rf noise due to shielding on the cable/s. I was thinking a Ps Audio conditioner or something. My Panamax 5500 is not a cheap piece by any margin but it does not eliminate the noise.

I appreciate the help folks. Just want rig to be more quiet. Concerned this high pitch will hurt my gear whether it be preamp/pwr/or spkrs.

Btw...amp plugged in alone is dead quiet as I suppose it should be as it uses B&O ice power class D.
mlsstl
1,429 posts
 
An "AC buzz" is the 60 Hz noise one hears when a ground connection is bad or the AC cord is plugged in backwards. It sounds like your noise is much higher frequency.

Where is your equipment located? If you have your amp, preamp and source equipment located in the same rack as your TV or similar equipment, they may be the source. TV equipment in particular can emit a lot of EMI at higher frequencies. (Also remember the "off" switch on a lot of modern equipment doesn't actually shut off power to the piece of equipment. It just puts it in standby so the internal circuits are still live - and noisy.)

Try removing your amp from the equipment rack and powering up the speakers with the amp several feet from any other electronics. If that solves the problem, then add back the preamp and audio source(s). In lieu of moving equipment, you could also try physically unplugging the other items.

If the noise is still gone, that means your interference is coming from other equipment on the rack. You'll simply need to physically separate the audio equipment from your other stuff. Often just a couple of feet will do the trick.
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