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
mlsstl
1,437 posts
 
Try to define the problem a bit more. You indicate this is not an AC buzz, but rather a white noise hiss from the mids/tweeters.

Is this audible from the listening position or do you have to put your ear to the speaker?

All electronics produce white noise but it is usually very low in level and inaudible at the listening position.

Do you have an usually efficient set of speakers? This could have nothing to do with your home's AC power but rather a mismatch between the gain of the amp and the speakers. If it's not audible at your listening position, I personally wouldn't worry about it much.
mnnc OP
175 posts
 
Well, I'm not sure if it's an ac buzz as I 'm not really sure what an ac buzz is. I am figuring that based on other users of the same gear report no noise/buzz/hiss. The noise is slightly audible from main listening position @ 11ft. in a moderately quiet room and clearly audible as you approach the spkrs closer. Particularly from middle channel which produces the most. The best way to describe the noise is it's a whining hiss...like you might have in a car audio system when alternator buzz is heard through the spkrs...just not as pronounced. The mains are 87 or 88db rating at nominal 6ohm. All spkrs are Nht Classic series.
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.
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