[SWG255]

I have two AC problems in my system and don't know how to go about solving them.

First and most annoying, I get moderately loud "pops" or "cracking" sounds through my speakers every time my furnace turns on or off. (This also happens with the air conditioning unit in summer) These pops happen even when the preamp's volume control is turned all the way down. They happen with either my Threshold or Carver Pro ZR amps hooked up.

Second, there's a very low-level hum or buzz (actually a hum with relatively lower-volume harmonics) constantly coming through my system. This too is independent of preamp volume setting or the amplifier I have connected to the preamp and speakers.

The audio system is on a separate 20-amp circuit, but I can't vouch for the quality of wiring between the breaker box and the wall outlets etc. I am not at all handy, and wouldn't have known whether an electrician was doing a great job or not when wiring the mains for my basement when it was finished and where the audio system was subsequently installed. I've had these problems the whole time my various systems have been in this house, I just feel the need to fix them now that I'm upgrading to better components.

What would you recommend I do to solve these two problems?  

I'd like to try the most cost-effective solutions first, if possible. I don't have the money to buy Bezorel power conditioners right now. <grin>

[Marbles]

As far as the buzz is concerned, this sounds suspiciously like a ground loop hum.

Are there any cable TV hookups in the system?  Is every item using the SAME circuit?

If you unhook the IC's going into the amp (then turn amp on), did the buzz go away or stay on?

If it went away, then hook the pre back up to the amps, but disconnect the IC's coming from all sources.

If the Buzz stayed when the IC's going into the amp were disconnected, then this could be the noise floor of the amps, or it could be something else in the house causing the problem.

[DVV]

As far as the buzz is concerned, this sounds suspiciously like a ground loop hum.

That, or possibly an electric motor with its brushes worn out, in which case it will spark, and sparks will be heard as buzzing while low in volume. Over time, as the brushes continue to wear out, it will become louder and louder.

For the answer to the above, you can do a simple test - take your hair dryer and hook it up in the same room, preferably the same wall outlet as your audio. Turn it on and listen - if there's an addtional noise like the one you already have, probably at a different frequency, then that's that, it's an electric motor. Have it serviced, the most important aspect of which is cleaning up the stator and installing new brushes.

If you don't have a hair dryer, butter up your wife by telling her the time has come for her to shine in audio and borrow hers.

Cheers,
DVV

[doug s.]

the buzz certainly sounds like ground-loop hum.  disconnecting components as described above can help locate the problem.  also, try a cheater plug(s) on equipment w/three-prong plugs.  these will also break ground-loops.  sometimes reversing two-prong plugs, plugging into different outlets, etc, will also break ground-loops.

re: the other a/c-furnace noise, sounds like serious power conditioning may be in order.

doug s.

[Psychicanimal]

Pops are usually FR impulses and no power filter will be able to stop them, as they're airborne.  You need to work at the appliance level and diagnose and decide what's the best course of action.

[OBF]

Psychic,

I'm not sure what FR impulses are, but it makes me think of how there's some sort of fan built into our basement fireplace (doesn't get used) with a wall switch, and flipping the switch sends a major pop through my system even through the Elgar and an Oneac.  Maybe that's the same thing you're talking about......?

[cotton]

I had a popping happen whenever my a/c compressor kicked on or when you start the dryer.  It turned out to be the line that connects the power from the service pole to the house.  I called the energy co. and they replaced the old line.  No problems anymore.  The service guy said that the cable had deteriorated in places and if something that placed a high load on the line kicked on, that the power load was too great.  Maybe you should have them come check it out. As long as it is outside of the house then your problem is fixed for free.

[Psychicanimal]

Psychic,

I'm not sure what FR impulses are, but it makes me think of how there's some sort of fan built into our basement fireplace (doesn't get used) with a wall switch, and flipping the switch sends a major pop through my system even through the Elgar and an Oneac.  Maybe that's the same thing you're talking about......?

RF impulses, that is.  Just a typo.

[Mike B.]

The ideal solution to the pops is to move the noise makers or the dedicated audio circuit to the opposite phase at the panel. As mentioned, the hum could be a ground loop problem. Some other things to try are using cheater plugs to eliminate the ground pin to see if that helps. Also, make sure your interconnects and power cords are separated.

[kevb]

Have you checked the voltage from your wall?  I was having annoying pops   and the lights would dim and flicker everytime my well pump kicked on.  I measured the voltage over a 3-4 day period and found that it was anywhere between 103 and 115 volts.  I was a little annoyed to say the least  I called the Hydro company and they solved the problem by boosting the voltage to 120-122 volt range consistently....and as a side effect the lights flicker no longer and there is a barely audible tick when the pump kicks on.  

Just something to consider, maybe the voltage to your place from the power lines is too low.

Kevin